CERTIFICATION
STUDY GUIDE
CERTIFIED HVAC DESIGNER (CHD)
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CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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ACKNOWLEDGEMENTS
The ASHRAE Certification Committee would like to thank the ASHRAE
Foundation Board of Trustees, without whose support this Certification Study
Guide would not have been possible. The Foundation’s commitment to
supporting an innovative, resource-rich study guide, which leverages
instructional design best practices, will help ensure effective adult learning
that drives desired outcomes and helps HVAC designers work toward
achieving their CHD certification goals.
CONTRIBUTORS
ASHRAE would like to thank the Certified HVAC Designers who contributed
written materials, technical expertise, and editorial comment in creation of this
study guide.
Nissun Feiner, C.Tech, CHD
Delta-T Designs Inc.
Kyle E. Koval, CHD
East Hills Engineering Associates LLC
Joshua Mee, CHD
Wendel Companies
Ahmad F. Shaar, BCXP, BEMP, CHD, HBDP, HFDP, OPMP
MAG International
Roger Tiguelo, CHD
GRG Prime Engineering Solutions Co
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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CONTENTS
INTRODUCTION ....................................................................................... 6
How to Use This Study Guide ................................................................ 7
CHD Exam Preparation Resources ..................................................... 1 0
SECTION 1 .1 : DOMAIN 1 , SYSTEM DESIGN, TASKS A-F .................. 1 2
Overview .............................................................................................. 1 2
Quick Quiz, Domain 1 , Section 1 .1 , Tasks A-F.................................... 1 4
Self-assessment .................................................................................. 1 5
SECTION 1 .2: DOMAIN 1 , SYSTEM DESIGN, TASKS G-L .................. 1 7
Overview .............................................................................................. 1 7
Quick Quiz, Domain 1 , Section 1 .2, Tasks G-L ................................... 1 8
Self-assessment .................................................................................. 1 9
SECTION 1 .3: DOMAIN 1 , SYSTEM DESIGN, TASKS M-R .................. 21
Overview .............................................................................................. 21
Quick Quiz, Domain 1 , Section 1 .3, Tasks M-R ................................... 22
Self-assessment .................................................................................. 23
SECTION 1 .4: DOMAIN 1 , SYSTEM DESIGN, TASKS S-Z ................... 25
Overview .............................................................................................. 25
Quick Quiz, Domain 1 , Section 1 .4, Tasks S-Z.................................... 26
Self-assessment .................................................................................. 27
DOMAIN 1 : SYSTEM DESIGN PRACTICE EXAM QUESTIONS ........... 30
SECTION 2: DOMAIN 2, DESIGN CALCULATIONS ............................. 39
Overview .............................................................................................. 39
Quick Quiz, Domain 2, Tasks A-J ........................................................ 40
Self-assessment .................................................................................. 41
DOMAIN 2: DESIGN CALCULATIONS PRACTICE EXAM QUESTIONS
................................................................................................................. 43
SECTION 3: DOMAIN 3, PROCEDURAL ............................................... 49
Overview .............................................................................................. 49
Quick Quiz, Domain 3, Tasks A-K ....................................................... 50
Self-assessment .................................................................................. 51
DOMAIN 3: PROCEDURAL PRACTICE EXAM QUESTIONS ............... 53
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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SECTION 4.1 : DOMAIN 4, COORDINATION, TASKS A-J .................... 56
Overview .............................................................................................. 56
Quick Quiz, Domain 4, Section 4.1 , Tasks A-J .................................... 57
Self-assessment .................................................................................. 58
SECTION 4.2: DOMAIN 4, COORDINATION, TASKS K-U ................... 60
Overview .............................................................................................. 60
Quick Quiz, Domain 4, Section 4.2, Tasks K-U ................................... 61
Self-assessment .................................................................................. 62
DOMAIN 4: COORDINATION PRACTICE EXAM QUESTIONS ............ 64
MY CHD CERTIFICATION EXAM STUDY MAP .................................... 69
Task Notes ........................................................................................... 69
Study Plan ........................................................................................... 76
PRACTICE EXAM QUESTIONS: ANSWER KEY .................................. 77
Domain 1 : System Design ................................................................... 77
Domain 2: Design Calculations ............................................................ 78
Domain 3: Procedural .......................................................................... 79
Domain 4: Coordination ....................................................................... 79
APPENDIX .............................................................................................. 80
Common HVAC Design Formulas ....................................................... 80
GLOSSARY ............................................................................................. 89
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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INTRODUCTION
ASHRAE is an international membership society committed to the
advancement of the arts and sciences of heating, ventilation, air-conditioning,
and refrigeration to serve humanity and promote a sustainable world. The
Certified HVAC designer (CHD) certification program supports this mission by
validating job competency as understood in internationally recognized
technical information, reflecting the best practices that lead our industry.
PURPOSE OF THE CHD CERTIFICATION
The CHD certification program validates competency of the HVAC designer,
working under the responsible charge of an engineer, to do the following:
Design HVAC systems to meet building/project requirements, including load
calculations, equipment selection and sizing, mechanical equipment room design,
duct and piping design, and layout for the development of HVAC plans for permit
and construction.
This Study Guide provides a framework and tools to help you self-assess
your knowledge in HVAC design and create a customized, self-paced study
plan for the CHD exam. ASHRAE offers numerous resources in the field. The
Study Guide will help you target which resources are most beneficial based
on your own professional development needs.
In this Study Guide, you, the candidate, are expected to evaluate your
personal skills and qualifications against numerous Tasks broken down into
individual Domains.
Depending on your experience level, some of these Tasks may be daunting
and unfamiliar. If that is the case, consider it an opportunity for growth and
devote extra attention to these matters. David Underwood, P. Eng., 201 5201 6 ASHRAE President, once said that “we in the engineering community
More information about the
CHD credential and eligibility
criteria can be found on the
ASHRAE website and in the
CHD Candidate Guidebook.
are in the solutions industry.” Based on this statement, it is your job to identify
problems and produce solutions. The Tasks included in Domains 1 -4
represent the skills necessary to produce solutions for HVAC-related
problems, and this Study Guide represents your opportunity to fill gaps in
your knowledge or experience base.
Using navigation buttons at top of screen: The buttons located at the top
of each page allow you to navigate through this document. Click on these
buttons to take you Back to view the last page you were on or to the First
Page, Previous Page, Next Page, or Last Page. The Glossary button
provides a direct link to the full glossary.
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
Clicking links in this document
will open in a browser window.
You will need to navigate back
to the PDF to pick up where
you left off.
6
THE OVERARCHING GOALS OF THE STUDY GUIDE ARE TO:
•
•
•
•
Provide a framework and tools for customized, self-paced exam preparation
Focus your review on key elements of recommended exam preparation
resources
Review knowledge needed to design HVAC systems to meet building/project
requirements
Build knowledge and skills across the four (4) Domains of the CHD exam,
which are:
Domain 1 : System Design
Domain 2: Design Calculation
Domain 3: Procedural
Domain 4: Coordination
•
•
•
Identify key terms and concepts used by HVAC designers
Provide the opportunity for you to test your acumen and readiness for the
CHD exam
Help you assess your own individual core content strengths and weaknesses,
and build a study map customized for your needs
How to Use This Study Guide
This Study Guide is designed as a workbook that contains tools you can use
to assess what you need to focus on as you prepare to take the exam.
The Study Guide is organized by Domains and Tasks. There are four
Domains total, some of which have numerous Tasks (Domain 1 has 26
Tasks, for example), so we’ve broken them down into segments. The CHD
certification exam was developed to assess your competence to perform
each of these Tasks as organized under each Domain, so this is a great way
to organize your study leading up to the exam and to also build and validate
your knowledge, skills, and abilities as an HVAC designer.
ASHRAE offers numerous resources to help you study for the CHD
certification exam; however, which resources do you need to review to
prepare for the exam? The tools in this Study Guide link the Domains and
Tasks with the resources available from ASHRAE to help you review and
study the content. The tools will also help you determine which Tasks you
need to focus upon. So, for example, if through the Self-assessment and
Quick Quiz contained herein you discover that you have limited knowledge of
Domain 1 : System Design, Task A: Size supply, return, and exhaust ducts,
the Study Guide will direct you to the 201 7 ASHRAE Handbook
Fundamentals, Chapter 21 .
—
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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ASHRAE Resources are listed
in this Study Guide and are
available in the ASHRAE
Bookstore
Study Tools
I n th i s S tu d y G u i d e yo u wi l l fi n d th e fo l l o wi n g to o l s fo r e ach D o m ai n th at wi l l
help you assess what you already know, and importantly, what you don’t
kn o w, s te p- by- s te p:
•
Qu i ck Qu i z
•
S e l f- as s e s s m e n t, i n cl u d i n g th e Tas k- by- Tas k R e s o u rce G u i d e , wh i ch wi l l
d i re ct yo u to
resources you can use to study, including “deep dive”
re s o u rce s i n s o m e i n s tan ce s yo u can u s e to d e l ve d e e pe r i n to th at to pi c
•
P racti ce E xam Q u e s ti o n s
•
S tu d y M ap
U s e d to g e th e r, th e
study tools in the Guide and ASHRAE’s resources
wi l l
h e l p yo u cre ate a targ e te d , cu s to m i z e d s tu d y pl an bas e d u po n yo u r o wn
n e e d s . Yo u wi l l n o te th at we h ave b ro ke n s o m e D o m ai n s i n to m u l ti pl e
s e cti o n s to h e l p yo u pace yo u rs e l f th ro u g h th e m ate ri al .
Yo u wi l l s tart e ach s e cti o n by taki n g a Qu i ck Qu i z wh i ch wi l l h e l p yo u te s t
yo u r kn o wl e d g e o f ke y te rm s an d co n ce pts fo r th at s e cti o n . N e xt, yo u wi l l
co m pl e te a S e l f- as s e s s m e n t to captu re th e are as yo u n e e d to fo cu s u po n as
yo u s tu d y fo r yo u r ce rti fi cati o n e xam . Th e s e to o l s wi l l h e l p yo u as s e s s yo u r
kn o wl e d g e an d o rg an i z e yo u r s tu d y o f th e co n te n t.
You’ll find instructions for how to use each study tool throughout this Study
, but here’s an overview:
Guide
Using the Study Guide and ASHRAE Resources Together
We re co m m e n d u s i n g th e s tu d y to o l s fo r e ach D o m ai n to g u i d e yo u r co u rs e
o f s tu d y an d h e l p yo u pre pare fo r th e C H D e xam :
STEP
1
STEP
R e ad th e Ove rvi e w an d take th e Qu i ck Qu i z an d S e l fas s e s s m e n t fo r e ach s e cti o n o f th e S tu d y G u i d e , s tarti n g
wi th D o m ai n 1 , Tas ks A- F.
R e vi e w th e AS H R AE R e s o u rce s fo r e ach Tas k as o u tl i n e d i n th e
2
Tas k- by- Tas k R e s o u rce G u i d e i n cl u d e d i n th e S e l f- as s e s s m e n t,
fo cu s i n g yo u r i n i ti al re vi e w o n tas ks yo u m arke d as " s o m e wh at"
o r " n o t ve ry" co n fi d e n t. R e co rd n o te s abo u t th e to pi cs yo u n e e d
to s pe n d ti m e s tu d yi n g .
STEP
3
Wh e n yo u h ave co m pl e te d yo u r fi rs t fu l l re vi e w o f al l fo u r
D o m ai n s an d th e s tu d y to o l s fo r e ach o n e , re tu rn to th e
S tu d y G u i d e to co m pl e te yo u r S tu d y M ap. Th i s fi n al s tu d y
to o l wi l l h e l p yo u m ap o u t yo u r co u rs e o f s tu d y l e ad i n g u p
to th e ce rti fi cati o n e xam .
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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Practice Exam Questions
The Study Guide also includes Practice Exam Questions, organized by
Domain. You can use these in several ways:
• As a pre-test to check your baseline knowledge
• As a post-test after completing your review to see how you might do on
the exam
• As a study and practice tool leading up to the exam, to help check your
progress
The answer key in the back of the Study Guide includes feedback with the
Domain and Task number to help you go back and revisit the content as
needed. Remember, you can find the right resource for each Task in the
Self-assessments, which include a Task-by-Task guide to the ASHRAE
Resources.
Glossary and Search
Glossary terms are defined within the text. Click any bolded term to see its
definition. You can also access all of the terms at any time by navigating to
the glossary by clicking this button.
At any time you can search the Study Guide to find terms or concepts you
want to study or review by clicking here.
Evaluation
We want to hear from you! Please click this link to complete an evaluation of
this Study Guide when you have completed it.
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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CHD Exam Preparation Resources
CHD RESOURCES
ASHRAE publications available to help you prepare for the CHD examination may
be purchased in the ASHRAE Bookstore:
https://www.techstreet.com/ashrae/index.html.
Publications
Primary Publications
•
•
•
201 9 ASHRAE Handbook—HVAC Applications
201 7 ASHRAE Handbook—Fundamentals
201 6 ASHRAE Handbook—HVAC Systems & Equipment
Secondary Publications
•
•
•
•
•
•
•
•
•
•
ANSI/ASHRAE Standard 1 5, Safety Standard for Refrigeration Systems and
Designation and Classification of Refrigerants
ANSI/ASHRAE Standard 55, Thermal Environmental Conditions for Human
Occupancy
ANSI/ASHRAE Standard 62.1 , Ventilation for Acceptable Indoor Air Quality
ANSI/ASHRAE/IES Standard 90.1 , Energy Standard for Buildings Except LowRise Residential Buildings
Standard 90.1 User's Manual
ANSI/ASHRAE/IES Standard 202, Commissioning Process for Buildings
and Systems
ANSI/ASHRAE Standard 209, Energy Simulation Aided Design for Building
Except Low-Rise Residential Buildings
ASHRAE Guideline 36, High-Performance Sequences of Operation for HVAC
Systems
Principles of Heating, Ventilating, and Air-Conditioning
Air-Conditioning Systems Design Manual, 3rd Edition
ASHRAE Learning Institute (ALI) and eLearning Center Courses
• The ASHRAE Learning Institute (ALI, https://www.ashrae.org/professionaldevelopment) and ASHRAE eLearning On Demand
(https://www.ashrae.org/professional-development/elearning-on-demand) offer
a wide range of archived, online courses
(https://www.techstreet.com/ashrae/subgroups/48292), professional
development seminars, and short courses on ASHRAE Standards and
Guidelines. ASHRAE also offers training for companies or chapters.
• CHD Practice Exam https://store.lxr.com/product.aspx?id=1 745
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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Codes
•
I CC,
International Fire Code
•
I CC,
International Building Code
•
I CC,
International Mechanical Code
•
I CC
•
N FP A 1 0 1 ,
Life Safety Code
•
N FP A 9 2 A,
Standard for Smoke-Control Systems Utilizing Barriers and
–
201 8,
International Green Construction Code (IgCC)
Pressure Differences
•
N FP A 9 2 B ,
Standard for Smoke Management Systems in Malls, Atria, and
Large Spaces
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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DOMAIN 1 , TASKS A-F
SECTION 1 .1 :
DOMAIN 1 , SYSTEM DESIGN,
TASKS A-F
Overview
I n D o m ai n 1 , yo u wi l l re vi e w th e Tas ks re l ate d to th e
art
o f H VAC , i n vo l vi n g
th e co n ce ptu al i z ati o n an d h i g h e r- l e ve l d e s i g n . At th i s s tag e , yo u r d e s i g n
be g i n s wi th a bl an k can vas bu t b e g i n s to m o ve fro m abs tract i n te n t, to a s o l i d
fo u n d ati o n o n wh i ch th e re s t o f yo u r d e s i g n wi l l bu i l d .
Li ke an y art, H VAC can al s o be s u b j e cti ve . I t i s a g i ve n th at yo u n e e d to h e at,
co o l , ve n ti l ate , e tc. , bu t th e s e are th e e n d , n o t th e m e an s . Th e s ki l l s o u tl i n e d
i n D o m ai n 1
are wh e re yo u e xe rci s e yo u r cre ati vi ty; yo u r co m pe te n cy i n th e s e
s ki l l s wi l l be wh at s e ts th e m as te r pai n te r apart fro m th e am ate u r h o bbyi s t.
Tas ks A- F wi l l te s t yo u r abi l i ty to b re ak o u t yo u r co n ce pt i n to i n d i vi d u al
s e g m e n ts th at can be e xpan d e d u po n l ate r.
How these concepts might apply day-to-day
S ay yo u are wo rki n g o n a s i n g l e - l e ve l o ffi ce bu i l d i n g ; yo u m i g h t n e e d to l o o k
at th e fo l l o wi n g facto rs :
•
C an yo u i d en ti fy wh i ch ro o m s h ave co m m o n o p e rati n g co n d i ti o n s ?
•
B as e d o n bu i l d i n g o ri e n tati o n an d l o cati o n , can yo u i n fe r wh i ch o ffi ce s wi l l
b e h ave d i ffere n tl y d u ri n g d i ffe re n t ti m e s o f th e d ay?
By identifying each room’s unique demands, you can group them together to
d e ve l o p a
zoning
distribution systems
e q u i p m e n t an d
pl an , bu t yo u are al s o abl e to l o g i cal l y be g i n to l ay o u t yo u r
.
I n ad d i ti o n , yo u wi l l n e ed to i d e n ti fy an d u n d e rs tan d th e fo l l o wi n g :
•
Wh at i s th e be s t way to ro u te s u p pl y an d re tu rn d u cts to e ffe cti ve l y s e rve
th e s pace s , wh i l e u s i n g th e l e as t am o u n t o f e n e rg y?
•
Wh at i n te rfere n ce s o r co o rd i n ati o n wi th o th e r d i sci pl i n e s can yo u e xpe ct?
•
Wh e re d o yo u re q u i re exh au s t o r fre s h ai r?
•
C an yo u i d en ti fy th e be s t l o cati o n fo r m e ch an i cal e q u i pm e n t fo r
s e rvi ce abi l i ty o r n o i s e co n s i d e rati o n ?
•
D o yo u u n d e rs tan d th e d i ffe re n ce s i n te ch n o l o g i e s we l l e n o u g h th at yo u
h ave a fe e l i n g fo r wh i ch s ys te m type l e n d s i ts e l f be s t to th i s appl i cati o n ?
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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DOMAIN 1 , TASKS A-F
At this stage, everything is still vague; nothing is sized and no loads are
determined. You will not begin to perform calculations until Domain 2, but the
work that is done here will pave the way for these details to develop.
Remember that a building is only as strong as the foundation that supports it,
and your knowledge and ability at this stage will affect the outcome of all
other work down the line. In addition, your ability to understand and
compartmentalize these Tasks will further help you properly communicate
your intent to teammates who may be further developing them down the line.
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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DOMAIN 1 , TASKS A-F
Quick Quiz, Domain 1 , Section 1 .1 , Tasks A-F
Now, let’s test your knowledge of some key
term s/con cepts fou n d i n D om ai n
1 , Tasks A-F. For each d efi n i ti on or con cept, sel ect an d wri te i n th e correct
opti on from th e ch oi ces provi d ed .
TERMS
DEFINITIONS
Con trol seq u en ce
1 .
Th e g reatest appl i cati on of ____________________
h as been i n con j u n cti on wi th vari abl e- ai r-vol u m e (VAV)
E xh au st d u cts
Fl ow d i ag ram
system s for cool i n g - on l y servi ces.
2.
Th e ____________________ m easu res th e con trol l ed
vari abl e an d tran sm i ts to th e con trol l er a si g n al h avi n g
Peri m eter h eati n g
a pressu re, vol tag e, or cu rren t val u e rel ated by a
kn own fu n cti on to th e val u e of th e vari abl e bei n g
Sen sor
m easu red .
3.
Verti cal ____________________ m ay n eed to be
exten d ed to red u ce exh au st- to- i n take reci rcu l ati on an d
i m prove eq u i pm en t effecti ven ess.
4.
Wh en com pl eti n g testi n g , ad j u sti n g , an d bal an ci n g
(TAB) an d com m i ssi on i n g , con si d er posti n g l am i n ated
system ____________________ at or ad j acen t to
cool i n g an d h eati n g eq u i pm en t i n d i cati n g operati n g
i n stru cti on s, TAB perform an ce, com m i ssi on i n g
fu n cti on al perform an ce tests, an d em erg en cy sh u toff
proced u res.
5.
I n th erm al storag e system s, th e opti m al
____________________ resu l ts from trad e-offs
between th e costs of cool i n g th e storag e d u ri n g offpeak h ou rs an d th e cost of m eeti n g th e l oad d u ri n g on peak h ou rs.
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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CHECK ANSWERS
DOMAIN 1 , TASKS A-F
Self-assessment
What’s your baseline?
Read and consider each Task and assess your confidence level. Then
consult the resources for each Task (especially for those Tasks which you
marked “somewhat” or “not very” confident). You might want to skim the
resources on this first pass. Note “deep dive” resources are provided where
appropriate to guide you if want to expand your course of study on that topic.
Record notes in the last column about topics you need to spend additional
time studying, marking chapters and page numbers where appropriate to
guide you. You’ll use these notes to create your Study Map after you have
completed your Self-assessment of all four Domains.
How confident are you in your knowledge,
skills, and abilities in these job Tasks?
Task A: Size supply,
return, and exhaust ducts.
❑ Confident
❑ Somewhat
Task B: Prepare HVAC
zoning plans and sensor
locations in accordance
with building design.
❑ Confident
❑ Somewhat
Task C: Prepare control
sequences and
schematics.
❑ Confident
❑ Somewhat
confident
❑ Not very
confident
confident
❑ Not very
confident
confident
❑ Not very
confident
Task-by-Task
Resource Guide
My Notes (Topics, resources, and
page numbers I need to spend
time studying)
201 7 Fundamentals
Handbook,
Chapter 21
Deep dive: 201 9
Applications
Handbook,
Chapter 46
201 9 Applications
Handbook,
Chapter 48
Deep dive: 201 7
Fundamentals
Handbook, Chapter 7
201 9 Applications
Handbook,
Chapter 43
Deep dive: 201 7
Fundamentals
Handbook, Chapter
7; 201 9 Applications
Handbook, Chapter
48; ASHRAE
Guideline 36,
Chapters 4 and 5.
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
15
DOMAIN 1 , TASKS A-F
Task D: Design ductwork
and piping including shaft
and ceiling space
requirements.
❑ Confident
❑ Somewhat
Task E: Differentiate and
design HVAC system types
(e.g., variable air volume
[VAV], variable refrigerant
flow [VRF], radiant, thermal
storage, underfloor
systems, perimeter and
process systems).
❑ Confident
❑ Somewhat
Task F: Design HVAC flow
diagrams.
❑ Confident
❑ Somewhat
❑
❑
❑
confident
Not very
confident
confident
Not very
confident
confident
Not very
confident
201 7 Fundamentals
Handbook, Chapters
21 and 22
Deep dive: 201 7
Fundamentals
Handbook,
Chapter 40
201 6 Systems and
Equipment
Handbook, Chapters
1 , 2, 3, 4, 6, 1 0, 1 3,
1 6, and 51
Deep dive: 201 6
Systems and
Equipment
Handbook, Chapters
5, 7, 8, 9, 1 1 , 1 2, 1 4,
1 5, 1 7, 1 8
201 6 Systems and
Equipment
Handbook, Chapters
2, 3, 4, and 1 3
Deep dive: 201 7
Fundamentals
Handbook 1 , 5, 6, 7,
8, 9, 1 0, 1 1 , 1 2, 1 4,
1 5, 1 6, 1 7, and 1 8
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
16
DOMAIN 1 , TASKS G-L
SECTION 1 .2: DOMAIN 1 ,
SYSTEM DESIGN, TASKS G-L
Overview
Tasks G-L build upon the work that was done in Tasks A-F. While at this
stage no calculations have been completed, you will narrow in on some of the
minutiae that was left out in A-F. These Tasks are critical to carry your design
forward and ensure that your final design meets the design intent.
Some of the questions you will want to ask include the following:
• Looking at your preliminary duct or piping routing, can you refine the paths
to minimize pressure loss?
• Can you identify points that would allow for fewer elbows or take-offs?
• How well do you understand air distribution and grilles/diffusers/registers
(GDRs)?
• Can you properly select and lay them out to maximize comfort while
minimizing draft, noise, and pressure loss?
• Once calculations are produced, do you understand HVAC technology well
enough that you can select a system to use in this application and to
convey your design intent to relevant vendors?
• Do you properly understand all these Tasks to the point that you can
prepare a detailed design brief and prepare schematics, flow diagrams,
etc., to present to relevant stakeholders?
Competency in these Tasks will ensure that you’re able to properly
communicate your design, which is paramount to ensuring that whoever
carries your design from paper to the real world will achieve the goals you
have set from the beginning.
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
17
DOMAIN 1 , TASKS G-L
Quick Quiz, Domain 1 , Section 1 .2, Tasks G-L
Now, let’s test your knowledge of some key terms/concepts found in Domain
1 , Tasks G -L. For each defi n i ti on or concept, select an d wri te i n th e correct
opti on from th e choi ces provi ded.
TERMS
DEFINITIONS
Ai r-di ffu si on performance i ndex (ADPI )
1.
du ri ng cooli ng u n i t operati on only,
Ai r-h an dl i ng u n i ts (AH U s)
and space condition control i s
u su al l y l i m i ted to u se of room
Dehu m i di fi cati on
Desi g n loads
____________________ occu rs
thermostats.
2.
The ____________________ i s a
u sefu l tool i n predicti n g ou tl et
Ventu ri tu be
perform ance for fu l l y mi xed
systems.
3.
The ____________________ i s a
nozzle fol lowed by an expandi n g
recovery secti on to redu ce net
pressu re loss.
4.
Wh en calcu lati ng
_________________, heat losses
or g ai ns from th e ai r-di stribu ti on
system must be i n clu ded in the
total l oad for each room .
5.
____________________ can be
one of the m ore complicated pi eces
of equ i pmen t to speci fy or order,
because a vast array of choi ces are
avai lable and there i s no si ng len u m ber i den ti fi er that adequ ately
describes the desi red produ ct.
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
18
CHECK ANSWERS
DOMAIN 1 , TASKS G-L
Self-assessment
What’s your baseline?
Read and consider each Task and rank your confidence level. Then consult
the resources for each Task (especially those which you marked somewhat
or not very confident). You might want to skim the resources on this first
pass. Record notes in the last column about topics you need to spend
additional time studying, marking chapters and page numbers where
appropriate to guide you. You’ll use these notes to create your Study Map
after you have completed your Self-assessment of all four Domains.
How confident are you in your knowledge,
skills, and abilities in these job Tasks?
Task G: Design duct and
❑ Confident
fluid systems to minimize
❑ Somewhat
pressure loss and resultant
confident
power requirements.
❑ Not very
confident
Task H: Select HVAC
system based on
calculations (e.g., AHUs,
fans, pumps, chillers,
cooling towers).
❑ Confident
❑ Somewhat
Task I: Design proper air
diffusion and devices
following codes and
standards.
❑ Confident
❑ Somewhat
confident
❑ Not very
confident
confident
❑ Not very
confident
Task-by-Task
My Notes (Topics I Need to Spend
Resource Guide
time Studying)
201 7 Fundamentals
Handbook, Chapters
21 and 22
Deep dive: 201 7
Fundamentals
Handbook, Chapters
37 and 39
Deep dive: 201 6
Systems and
Equipment
Handbook, Chapters
1 , 2, 3, 4, 1 3, 21 , 40,
43, 44
201 7 Fundamentals
Handbook, Chapters
1 , 1 7, and 40
201 9 Applications
Handbook, Chapter
58
Deep dive: 201 6
Systems and
Equipment
Handbook, Chapter
20; 201 9 Applications
Handbook, Chapter
59; ASHRAE
Standard 55,
Chapters 6 and 7
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
19
DOMAIN 1 , TASKS G-L
Task J: Develop a detailed
HVAC design based on the
approved preliminary
building design concept
and site information.
❑ Confident
❑ Somewhat
Task K: Prepare HVAC
schematics, plan drawings,
elevation views, section
views, and installation
details.
❑ Confident
❑ Somewhat
Task L: Select diffusers
and grilles to meet thermal
comfort and ventilation
needs and coordinate with
architectural plans (e.g.,
ceiling grid, under floor
systems, sidewalls,
architectural specialties,
transfers).
❑ Confident
❑ Somewhat
❑
❑
❑
confident
Not very
confident
confident
Not very
confident
confident
Not very
confident
Deep dive: 201 6
Systems and
Equipment
Handbook, Chapters
3, 4, and 28; 201 7
Fundamentals
Handbook, Chapters
1 7, 1 8, and 40
Deep dive: 201 6
Systems and
Equipment
Handbook, Chapters
2, 3, 6, 1 0, 1 3, and
1 4; 201 7
Fundamentals
Handbook,
Chapter 1 9
201 6 Systems and
Equipment
Handbook,
Chapter 20
Deep dive: 201 6
Systems and
Equipment
Handbook,
Chapter 1 0; 201 7
Fundamentals
Handbook, Chapter
9; 201 9 Applications
Handbook, Chapter
58; ASHRAE
Standard 55,
Chapter 5
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
20
DOMAIN 1 , TASKS M-R
SECTION 1 .3: DOMAIN 1 ,
SYSTEM DESIGN, TASKS M-R
Overview
I n Tas ks A- L, yo u e val u ate d yo u r abi l i ti e s wi th re g ard to pre l i m i n ary d e s i g n
Tas ks wi th i n cre as i n g d e tai l . Tas ks M - R wi l l e val u ate yo u r u n d e rs tan d i n g o f
d e s i g n fu n cti o n al i ty, as we l l as d e s i g n s affe cti n g e xi s ti n g bu i l d i n g s .
R e n o vati o n s are o fte n m o re co m pl i cate d th an n e w co n s tru cti o n pro j e cts , as
th e d e s i g n e r i s o fte n o pe rati n g wi t h po o r as - bu i l t d o cu m e n tati o n an d i s o fte n
u n abl e to acce s s e xi s ti n g d u ct an d pi pi n g d i s tri bu ti o n . Yo u r abi l i ty to
co n fi d e n tl y e xe cu te Tas ks M - R wi l l d ras ti cal l y i n cre as e th e l i ke l i h o o d o f
pro j e ct s u cce s s wh e n d e al i n g wi th re n o vati o n s an d re tro fi ts . Fo r e x am pl e :
•
C an yo u i n ve s ti g ate an d au d i t th e e xi s ti n g s ys te m d e s i g n s , e val u ate
e xi s ti n g e q u i pm e n t, an d d e te rm i n e capaci ti e s u s i n g s u ppo rti n g
d o cu m e n tati o n ?
•
Are yo u abl e to u n d e rs tan d pro po s ed ch an g e s to th e bu i l d i n g an d
d e te rm i n e h o w th e H VAC s ys te m i s affe cte d ?
•
Are yo u abl e to e ffe cti ve l y co m m u n i cate wh at s ys te m s n e e d to be
d e m o l i s h e d o r m o d i fi e d ?
•
Are yo u abl e to re co m m e n d i n te g rati o n o f n e w te ch n o l o g i e s to i n cre as e th e
e ffi ci e n cy an d e ffe cti ve n e s s o f th e H VAC s ys te m s ?
•
Wh at u pg rad e s to th e e xi s ti n g s ys te m wi l l be n e ce s s ary to s u i t th e
p ro po s e d ch an g e s ?
•
Wh at ch al l e n g e s d o th e s i te co n d i ti o n s p o s e to yo u r pro po s ed d e s i g n ?
•
Wi l l yo u be abl e to re co m m e n d s o l u ti o n s th at wi l l m atch th e l o n g e vi ty o f th e
bu i l d i n g i n te rm s o f s e rvi ce ab i l i ty an d fu tu re e xpan s i o n ?
•
Wi l l yo u r s o l u ti o n s pro vi d e re d u n d an cy s trate g i e s to m i n i m i z e d o wn ti m e s
d u ri n g m ai n te n an ce ?
D u e to th e n atu re o f re n o vati o n s , an H VAC d e s i g n e r re l i e s h e avi l y o n
e ffe cti ve co o rd i n ati o n an d co m m u n i cati o n . Lack o f ad e q u ate pre parati o n
d u ri n g th e s e Tas ks d ras ti cal l y i n cre as e s th e l i ke l i h o o d o f co s t an d s ch e d u l e
o ve rru n s d u e to po o r d rawi n g s an d m i s s e d s i te co n d i ti o n s an d m ay e ve n
j e o pard i z e th e e ffe cti ven e s s o f o ve ral l d e s i g n .
J u s t l i ke Tas ks A- L, p ro pe r fo cu s an d atte n ti o n to th e s e s ki l l s wi l l pay
d i vi d e n d s d o wn th e ro ad .
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
21
DOMAIN 1 , TASKS M-R
Quick Quiz, Domain 1 , Section 1 .3, Tasks M-R
Now, let’s test your knowledge of some key terms/concepts found in Domain
1 , Tasks M -R. For each defi ni ti on or concept, select an d wri te i n th e correct
opti on from th e choi ces provi ded.
TERMS
DEFINITIONS
Ai r deli very equ i pm ent
1.
Li brary, equ i pm ent tech ni cal data sheets and as-
DDC or BAS systems
bu i l t drawi ng s can be obtai ned from the
____________________ and
Mai ntenance m an u al /
____________________ respecti vely.
Operati ng m an u al
Predicti ve maintenance
In an existing project’s O&M Documentation
2.
Vi brati on an alysi s to identi fy i mbalances, beari ng
wear, and m i sal i g n m en t i s an exampl e of
______________________.
3.
____________________ can monitor, calcu late,
and record system statu s, water u se, energ y u se at
the m ai n m eter or of parti cu lar end-u se systems,
demand, and h ou rs of operati on; as well as start
and stop bu i ldi ng systems.
4.
One ____________________ ri si ng i n popu lari ty i s
a fan array, whi ch u ses m u l ti ple plu g fans on a
comm on
plenum wall , thu s redu ci n g u ni t si ze.
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
22
CHECK ANSWERS
DOMAIN 1 , TASKS M-R
Self-assessment
What’s your baseline?
Read and consider each Task and rank your confidence level. Then consult
the resources for each Task (especially those which you marked somewhat
or not very confident). You might want to skim the resources on this first
pass. Record notes in the last column about topics you need to spend
additional time studying, marking chapters and page numbers where
appropriate to guide you. You’ll use these notes to create your Study Map
after you have completed your Self-assessment of all four Domains.
NOTE: Task P is based on experience, and there are no Resources available
for review or study.
How confident are you in your knowledge,
skills, and abilities in these job Tasks?
Task M: Evaluate
❑ Confident
proposed building design
❑ Somewhat
concept modifications for
confident
HVAC implications.
❑ Not very
confident
Task N: Integrate new
system technologies into
HVAC design (e.g.,
variable refrigerant flow
[VRF], electronically
commutated motor [ECM]
control, integrated
automation).
❑ Confident
❑ Somewhat
Task O: Research and
confirm capacities of
existing equipment and
obtain shop drawings of
existing equipment (e.g.,
air-handling systems,
chillers, cooling towers).
❑ Confident
❑ Somewhat
confident
❑ Not very
confident
confident
❑ Not very
confident
Task-by-Task
Resource Guide
201 7 Fundamentals
Handbook,
Chapter 1 9
Deep dive: 201 6
Systems and
Equipment
Handbook, Chapters
2, 3, 4, and 1 8
201 9 Applications
Handbook, Chapters
42 and 63
Deep dive: 201 6
Systems and
Equipment
Handbook, Chapters
4, 7, 1 8, and 45;
201 9 Applications
Handbook, Chapters
43 and 65; 201 8
International Green
Construction Code,
Chapters 7 and 8
201 9 Applications
Handbook,
Chapters 40
My Notes (Topics I Need to Spend
time Studying)
Deep dive: 201 9
Applications
Handbook,
Chapter 44
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
23
DOMAIN 1 , TASKS M-R
Task P: Prepare HVAC
demolition drawings of the
equipment and systems
that must be moved or
relocated to accomplish
retrofit.
Task Q: Recommend
system design options to
minimize machine or
system downtime (e.g.,
N+1 , 2N, fan array, direct
drive fans, VRF).
Task R: Recommend
system configurations to
facilitate future
maintenance (e.g., system
access, coil pull space,
motor replacement, safety
concerns).
❑
❑
❑
❑
❑
❑
❑
❑
❑
Confident
Somewhat
confident
Not very
confident
Task P: no
recommended
chapters
Confident
Somewhat
confident
Not very
confident
201 6 Systems and
Equipment
Handbook, Chapter 4
Confident
Somewhat
confident
Not very
confident
201 9 Applications
Handbook,
Chapter 40
Deep dive: 201 9
Applications
Handbook,
Chapter 60
Deep dive: 201 6
Systems and
Equipment
Handbook, Chapters
1 , 2, 3, 1 3, 1 8, 21 ,
and 44
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
24
DOMAIN 1 , TASKS S-Z
SECTION 1 .4: DOMAIN 1 ,
SYSTEM DESIGN, TASKS S-Z
Overview
By this stage of an HVAC design project, you have established a high-level
design intent, provided additional detail to help develop and mature the
design, reviewed existing conditions, and evaluated different options to suit
all these different circumstances.
Tasks S-Z will round out the rest of the design by providing needed detail. At
this point, you would incorporate calculations (to be reviewed in Domain 2)
and integrate them in your design. Tasks that you may want to consider
include the following:
• Can you adequately prepare drawings and schematics that show
distribution branches, piping loops, and system components?
• Are you able to identify the need for balancing and flow regulation, as well
as specify and document balancing dampers and valves?
• Are you able to size and select expansion tanks , heat exchangers, air
handlers, and boiler plants?
• Are you able to size and select pumps, valves, and fans?
These final touches complete your design and finish its journey from abstract
intent to a tangible, workable product. At this stage, you should have
identified all your conditions, variables, and operating parameters and
produced a design that will accurately and deliberately meet those metrics.
Once you are satisfied that you are sufficiently competent in Tasks A-Z of
Domain 1 , proceed to Domain 2.
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
25
DOMAIN 1 , TASKS S-Z
Quick Quiz, Domain 1 , Section 1 .4, Tasks S-Z
Now, let’s test your knowledge of some key terms/concepts found in Domain
1 , Tasks S-Z. For each defi ni ti on or concept, select and wri te i n the correct
opti on from the choi ces provi ded.
TERMS
DEFINITIONS
Ai r-si de
1.
A(n) _________________ econom izer uses
2.
____________________ fans may be forward-
Anci llary equ ipm ent
Cali brati on
outdoor air to reduce refrig erati on requ irem ents.
cu rved, backward-incli ned, or ai rfoi l, and si ng lewi dth/sin g le-inl et (SWSI ) or dou ble-wi dth/dou ble-i nlet
Centri fug al
(DWDI ) . ____________________ i s an energ y
analysis tool that u ses vector analysi s to evalu ate al l
Pi n ch technolog y
heating and cooli ng u ti li ti es i n a process.
3.
____________________ i s th e process of
com parin g a set of di screte m ag ni tu des or the
characteristi c cu rve of a con ti n u ou sly varyi ng
m ag ni tu de wi th an oth er set or cu rve previ ou sly
establ ished as a standard.
4.
A cen tral plant can be cu stom i zed wi thou t sacri fi ci n g
the stan dardizati on, fl exi bi li ty, and perform ance
requ i red to su pport the prim ary cooli n g and heating
equ i pment by carefu lly selecti ng
____________________, au tomati c control , and
faci li ty m anag em en t.
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
26
CHECK ANSWERS
DOMAIN 1 , TASKS S-Z
Self-assessment
What’s your baseline?
Read and consider each Task and rank your confidence level. Then consult
the resources for each Task (especially those which you marked somewhat
or not very confident). You might want to skim the resources on this first
pass. Record notes in the last column about topics you need to spend
additional time studying, marking chapters and page numbers where
appropriate to guide you. You’ll use these notes to create your Study Map
after you have completed your Self-assessment of all four Domains.
NOTE: This is the last set of Tasks for Domain 1 . Answer the Practice Exam
Questions that follow for Domain 1 before moving on to Domain 2.
How confident are you in your knowledge,
skills, and abilities in these job Tasks?
Task S: Design for
❑ Confident
balancing air and fluid
❑ Somewhat
systems (e.g., balancing
confident
dampers, balance valves,
❑ Not very
self-balancing control
confident
valves).
Task T: Prepare ductwork
and piping flow diagrams to
convey the design intent
(e.g., primary/secondary
systems, pumping and
isolation systems, duct
loops, exhaust risers with
sub-ducts.)
❑ Confident
❑ Somewhat
Task U: Design piping and
ductwork layout based on
calculated sizing and
required routing.
❑ Confident
❑ Somewhat
confident
❑ Not very
confident
confident
❑ Not very
confident
Task-by-Task
Resource Guide
201 9 Applications
Handbook,
Chapter 39
Deep dive: 201 6
HVAC Systems and
Equipment
Handbook,
Chapter 47; 201 7
Fundamentals
Handbook,
Chapter 37
201 6 Systems and
Equipment
Handbook, Chapters
3, 4, 5, 9, 1 0, 1 3, 21
Deep dive: 201 6
Systems and
Equipment
Handbook, Chapters
1 , 2, 6, 7, 8, 1 1 , 1 2,
1 4, 1 5, 1 6, 1 7, 1 8,
and 21
201 7 Fundamentals
Handbook, Chapters
21 and 22
Deep dive: 201 7
Fundamentals
Handbook,
Chapter 38
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
My Notes (Topics I Need to Spend
time Studying)
27
DOMAIN 1 , TASKS S-Z
Task V: Select expansion
tanks.
❑
❑
❑
Task W: Select major airside units.
❑
❑
❑
Task X: Size major heating
plant components.
❑
❑
❑
Task Y: Design leakdetection systems.
❑
❑
❑
Confident
Somewhat
confident
Not very
confident
201 6 Systems and
Equipment
Handbook,
Chapter 1 3
Deep dive: 201 6
Systems and
Equipment
Handbook,
Chapter 1 5
Confident
Somewhat
confident
Not very
confident
201 6 Systems and
Equipment
Handbook, Chapters
1 , 4, 5, and 1 0
Deep dive: 201 6
Systems and
Equipment
Handbook, Chapters
2, 3, 6, 7, 8, 9, 1 1 ,
1 2, 1 3,1 4, 1 5, 1 6, 1 7,
and 1 8
Confident
Somewhat
confident
Not very
confident
201 6 Systems and
Equipment
Handbook,
Chapter 32
Deep dive: 201 6
Systems and
Equipment
Handbook, Chapters
3, 5, 1 3, and 1 5
Confident
Somewhat
confident
Not very
confident
201 7 Fundamentals
Handbook,
Chapter 29
Deep dive: 201 6
Systems and
Equipment
Handbook, Chapter
1 8; ASHRAE
Standard 1 5,
Chapters 7 and 8
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
28
DOMAIN 1 , TASKS S-Z
Task Z: Select major
cooling plant components:
1 . fans
❑
❑
❑
2. coils
❑
❑
❑
3. piping
❑
❑
❑
4. pumps
❑
❑
❑
Confident
Somewhat
confident
Not very
confident
201 6 Systems and
Equipment
Handbook,
Chapter 21
Deep dive: 201 6
Systems and
Equipment
Handbook, Chapter 4
Confident
Somewhat
confident
Not very
confident
201 6 Systems and
Equipment
Handbook,
Chapter 23
Deep dive: 201 6
Systems and
Equipment
Handbook, Chapters
5, 1 3, and 27
Confident
Somewhat
confident
Not very
confident
201 7 Fundamentals
Handbook,
Chapter 22
Confident
Somewhat
confident
Not very
confident
201 6 Systems and
Equipment
Handbook,
Chapter 44
Deep dive: 201 6
Systems and
Equipment
Handbook, Chapters
5 and 1 3
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
29
DOMAIN 1
DOMAIN 1 : SYSTEM DESIGN
PRACTICE EXAM QUESTIONS
1.
CHECK ANSWERS
CLEAR ANSWERS
Whi ch desi g n method sh ou ld be u sed to si ze ducts down stream of
termi nal boxes, toi l et exhau st du cts, and other l ow-pressu re systems?
2.
3.
A.
equ al fri cti on meth od
B.
stati c fri cti on method
C.
stati c reg ai n method
For du ct sizi ng , th e stati c reg ai n m ethod shou l d be avoi ded for:
A.
posi ti ve-pressu re du ct system s
B.
neg ati ve-pressu re systems
C.
l ow-pressu re du ct system s
Whi ch of th e fol l owi n g statem ents i s MOST accu rate reg ardi ng the Task
of sequ enci ng h eati n g and cool i ng ?
A.
Central fan system s shou ld n ot u se cool ou tdoor ai r i n sequ ence
between heati ng and cool i ng .
B.
H eati ng an d cool i ng shou l d be su ppli ed si m u l taneou sl y for h u m i di ty
control .
C.
Zoni ng and system sel ecti on sh ou ld el i mi nate, or at l east m in i m i ze,
si m u l taneou s h eati ng and cooli ng .
4.
When choosi n g a chi ller, thi s type of system requ i res g reater care i n
desi g n of the control system an d con trol sequ ences bu t i s u su al l y m ore
effi ci en t.
A.
constant fl ow
B.
vari abl e fl ow
C.
vari abl e-pri mary flow
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DOMAIN 1
5. A control schematic MOST frequently includes which of the following?
CHECK ANSWERS
CLEAR ANSWERS
A. description of the layout
B. description of the system functions
C. layout of the Input/output objects
6. When looking at the schematic of a heating system, the air-distribution
system is made up of which two items?
A. boiler(s); heating coil(s)
B. heating coil(s); zone(s)
C. zone(s); boiler(s)
7. Buildings over how many stories high USUALLY require vertical shafts to
consolidate mechanical, electrical, and telecommunication distribution
throughout the facility?
A. 3
B. 5
C. 7
8. When determining the proper accounting of leakage-related impacts on
fan energy and space conditioning loads, the recommended MAXIMUM
system leakage is what percentage of design airflow.
A. 2%
B. 5%
C. 8%
9. When designing a fluid flow system, there are two concerns that need to
be taken into consideration. They are the:
A. flow/pressure relationship and the sizing of pipe
B. number of joints in the plan and flow/pressure relationship
C. number of joints in the plan and the sizing of pipe
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DOMAIN 1
1 0. There are three basi c types of
cool i ng only,
variable refrigerant flow (VRF) systems :
heat pump, and ___________.
A.
ai r-cool ed ou tdoor
B.
heat recovery
C.
water-cool ed ou tdoor
1 1 . The th ermal layer of water i n a ch i ll ed-water thermal storag e tank,
separati n g warmer water at the top and cool er water at the bottom i s
cal l ed wh i ch of the fol lowi ng ?
A.
a therm ocl i ne
B.
therm al bri dg i n g
C.
therm al storag e capaci ty
1 2. The fl ow di ag ram of a two-pi pe ch ang e-over system MU ST contai n
________.
A.
boi ler, pu m p, and l oad
B.
ch i l l er, boi l er, an d pu m p
C.
ch i l l er, pu mp, and load
1 3. The m ost com mon en g i n eeri n g desi g n fl ow l oss cal cu l ati on sel ects a pi pe
si ze based on whi ch of the fol l owi n g ?
A.
al l owabl e pressu re drop and desi red fl ow rate
B.
desi g n ed l en g th of pi pe and all owable pressu re drop
C.
desi red fl ow rate and desi g ned leng th of pi pe
1 4. Whi ch of th e fol l owi n g i s the BEST desi g n recom mendati on to m i n i m i ze
pressu re loss i n an ai r system ?
A.
Avoi d u se of rou nd spi ral du cts.
B.
Rou te du cts as strai g ht as possi bl e.
C.
U se consecu ti ve and close-cou pl ed fi tti ng s.
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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CHECK ANSWERS
CLEAR ANSWERS
DOMAIN 1
1 5. What i s the tem peratu re di fference between th e water en teri n g and the
CHECK ANSWERS
CLEAR ANSWERS
water l eavi n g th e cool i ng tower cal led?
A.
approach
B.
cool i n g capaci ty
C.
range
1 6. The
occupied zone i s g en eral l y consi dered to be th e room volu me
between th e floor l evel an d ___ above the floor.
A.
6 ft/1 . 8 m
B.
8 ft/2. 4 m
C.
1 0 ft/3. 0 m
1 7. I n the very earl y ph ases of bu i ldi ng desi g n, the combi ned m ech ani cal and
electri cal space requ i rem ent of m ost bu i l di ng s i s wh at percen tag e of the
total bu i l di ng fl oor area?
A.
3-5%
B.
6-9%
C.
1 0-1 2%
1 8. The person responsi bl e for selecti ng con trol valves, coordi nati ng th em
wi th heat tran sfer devices, and provi di ng a sch edu l e of devi ces and a
detail ed conn ecti on schemati c i s whi ch of the foll owi ng ?
A.
archi tect
B.
H VAC desi g ner
C.
project eng i neer
1 9. Thi s type of di ffu ser featu res a seri es of open i n gs arrang ed i n a radi al
pattern arou n d the center of the di ffu ser face.
A.
sl aqu e-face
B.
squ are
C.
swi rl
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DOMAIN 1
20. A common application to compare retrofit alternatives for existing
buildings is which of the following?
CHECK ANSWERS
CLEAR ANSWERS
A. plug loads
B. energy modeling
C. building orientation
21 . A mathematical model is a description of the behavior of a system. It
contains which components?
A. input variables, output variables, data driven models
B. input variables, output variables, system structure and parameter
properties
C. system structure and parameter properties, data driven models,
output variables
22. This system technology has been used primarily to protect expensive
equipment from catastrophic failure, ensure safety, and provide alarms
when a measured variable goes outside its acceptable operating range.
A. automated-fault detection and diagnosis (AFDD)
B. building automation systems (BASs)
C. indoor environmental quality (IEQ)
23. Periodically, the capacity of existing buildings may need to be evaluated.
Doing so is called _________.
A. ongoing commissioning
B. recommissioning
C. retrocommissioning
24. (P-work experience) _________ are used to indicate overall modifications
to existing systems.
A. as-built drawings
B. demolition drawings
C. flow diagrams
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DOMAIN 1
25. To eliminate maintenance and replacement, which type of motor would be
MOST appropriate for a fan system?
A. electronically commutated motor (ECM)
B. belt-drive
C. permanent split capacitor (PSC)
26. This type of maintenance schedule is MOST typically used to extend
useful life of essential building equipment, such as pumps, air handlers,
boilers, ductwork, elevators, and transformers.
A. predictive
B. preventive
C. run-to-failure
27. The built-in benefit of a ____________ is that, when properly field
adjusted, all system flow paths have the same head loss.
A. automatic flow limiter
B. orifice flowmeter
C. static balancing valve
28. Dynamic and ________ dampers are the two basic styles of traditional
balance dampers.
A. motor operated
B. pressure independent
C. static
29. Parallel pumping arrangements increase what flow characteristic?
A. increased flow
B. increased head
C. redundancy
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CHECK ANSWERS
CLEAR ANSWERS
DOMAIN 1
30. When designing ductwork there are two (2) methods, static regain and
________.
CHECK ANSWERS
CLEAR ANSWERS
A. critical path
B. equal friction
C. low pressure
31 . What is the approximate MAXIMUM friction loss that should be
considered when sizing a traditional piping system?
A. 4 ft per 1 00 ft of pipe (400 Pa/m)
B. 5 ft per 1 00 ft of pipe (500 Pa/m)
C. 6 ft per 1 00 ft of pipe (600 Pa/m)
32. This type of terminal unit is generally applied to areas with higher
concentrations of sensible cooling loads and requires elevated chilledwater temperatures.
A. chilled beam
B. fan-coil unit
C. variable air volume (VAV) box
33. This type of expansion tank has a flexible membrane that is inserted
between the air and the water.
A. bladder
B. diaphragm
C. open
34. A disadvantage of air-side economizers in some systems is that the unit
must be located __________.
A. central to the building
B. near an indoor wall
C. near an outdoor wall
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DOMAIN 1
35. A client is building a new building and wishes to use a high efficiency
boiler and the load calculations you performed indicate the building has
1 50,000 Btu/hr/heat loss. Designing around a 40 degree delta T, how
many gallons per minute/liters per second of water are required for the
system design?
CHECK ANSWERS
CLEAR ANSWERS
A. 7.5 gpm/
B. 1 5 gpm/
C. 75.0 gpm/
36. In which method of refrigerant leak detection, the object to be tested is
pressurized with air or nitrogen?
A. bubble
B. dye
C. electronic
37. What is the MOST important selection criterion for condenser fans?
A. energy use
B. noise level
C.
static pressure
38. When selecting a coil, which of the following should be considered?
A. air quality
B. energy consumption
C. space limitations
39. For chilled water, which of the following is the MOST common piping
material?
A. chlorinated polyvinyl chloride (CPVC)
B. steel, galvanized
C. steel type F (CW)
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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DOMAIN 1
40. Which type of pump is mounted on a horizontal motor supported by the
motor or pump foot mountings?
CHECK ANSWERS
CLEAR ANSWERS
A. close-coupled, single-state, end-suction
B. frame-mounted, end-suction
C. vertical in-line
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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DOMAIN 2
SECTION 2: DOMAIN 2, DESIGN
CALCULATIONS
Overview
I n D o m ai n 1 , yo u we re co n ce rn e d wi th tas ks an d s ki l l s th at we re m o re
co n ce pt d ri ve n . Yo u h ad to e s tabl i s h an abs tract d e s i g n i n te n t an d fu rth e r
re fi n e i t i n to a fi n al pro d u ct. I n D o m ai n 1 , h o we ve r, yo u we re n o t re al l y
co n ce rn e d wi th th e actu al cal cu l ati o n s . I n s te ad , yo u we re fo cu s e d o n wh at
yo u d o be fo re an d afte r th e cal cu l ati o n s s tag e .
I f D o m ai n 1
i s th e art o f H VAC , th e n D o m ai n 2 i s ce rtai n l y th e s ci e n ce . Th e
s ki l l s th at are te s te d u n d e r th i s D o m ai n e n s u re th at yo u r d e s i g n ach i e ve s i ts
g o al s . I n th i s D o m ai n yo u wi l l e s tabl i s h :
•
H o w m u ch e n e rg y yo u m u s t ad d to o r re m o ve fro m th e s p ace .
•
H o w m u ch fre s h ai r o r e xh au s t th e s p ace re q u i res .
•
D u ct an d pi pe s i z e s to carry th e h e ati n g & co o l i n g m e d i u m s .
•
S ys te m co m po n e n ts to s u i t th e u n i q u e d e m an d s o f d i ffe re n t h e ati n g an d
co o l i n g m e d i u m s .
Wh i l e D o m ai n 1
bu i l d s a s o l i d fo u n d ati o n fo r yo u r d e s i g n , th o s e e ffo rts are
was te d i f yo u r cal cu l ati o n s are i n accu rate o r b as e d o n i n co rre ct as s u m pti o n s .
Much like the systems we design, the designer’s skill must be well balanced.
I f n o t, th e bu i l d i n g o ccu pan ts are s u re to n o ti ce .
On ce yo u are s ati s fi e d th at yo u are s u ffi ci e n tl y co m pe te n t i n al l o f th e Tas ks
i n D o m ai n 2 , m o ve o n to D o m ai n 3 .
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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DOMAIN 2, TASKS A-J
Quick Quiz, Domain 2, Tasks A-J
Now, let’s test your knowledge of some key terms/concepts found in Domain
2, Tasks A-J. For each definition or concept, select and write in the correct
option from the choices provided.
TERMS
DEFINITIONS
CD1 1 -3
1.
A(n) ____________________ pipe operates at the lowest
overall stress level.
2.
____________________ ventilation is the intentional
movement of air into and out of a building suing fans,
ductwork, intake louvers, and exhaust grilles.
3.
____________________ is the normal force per unit
area.
4.
Heating calculations use simple worst-case assumptions:
no solar or internal gains, and no
____________________ (with all heat losses evaluated
instantaneously).
5.
Ventilation ____________________ may be offset with
heat recovery equipment.
6.
For pipe sizes 2 in. and over, minimum velocities
corresponding to a ____________________ of
0.75 ft/1 00 ft are normally used.
7.
Peak design heating and ____________________
calculations seek to determine the maximum rate of
heating and cooling energy transfer at any point in time.
8.
Noise, ____________________, and installation and
operating costs all limit the maximum and minimum
velocities in piping systems.
9.
____________________ determines the size of a duct,
knowing airflow, such that the design velocity is not
exceeded.
Cooling load
Erosion
Head loss
Heat load
Heat storage
Mechanical
Pressure
Unrestrained
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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CHECK ANSWERS
DOMAIN 2, TASKS A-J
Self-assessment
What’s your baseline?
Read and consider each Task and rank your confidence level. Then consult
the resources for each Task (especially those which you marked somewhat
or not very confident). You might want to skim the resources on this first
pass. Record notes in the last column about topics you need to spend
additional time studying, marking chapters and page numbers where
appropriate to guide you. You’ll use these notes to create your Study Map
after you have completed your Self-assessment of all four Domains.
NOTE: This is the only set of Tasks for Domain 2. Answer the Practice Exam
Questions that follow for Domain 2 before moving on to Domain 3.
How confident are you in your knowledge,
skills, and abilities in these job Tasks?
Task A: Calculate HVAC
❑ Confident
system requirements (e.g., ❑ Somewhat
water flows, airflows, pump
confident
heads, suction heads,
expansion compensation). ❑ Not very
confident
Task B: Assist in the
preparation of project
estimates for comparative
system selection (e.g.,
installed cost, operating
cost, space limitations,
water availability, power
requirements).
Task C: Calculate all
piping and ductwork sizing
based on flow rates
received from the project
engineer and adapted in
size and route to comply
with the existing physical
constraints.
Task D: Adjust thermal
load or HVAC requirement
estimates based on
modifications to building.
❑ Confident
❑ Somewhat
confident
❑ Not very
confident
Task-by-Task
Resource Guide
201 7 Fundamentals
Handbook, Chapters
21 and 22.
Deep dive: 201 7
Fundamentals
Handbook, Chapters
36 and 39
201 9 Applications
Handbook,
Chapter 38
My Notes (Topics I Need to Spend
time Studying)
❑ Confident 201 7 Fundamentals
Chapters
❑ Somewhat Handbook,
21 and 22
confident
❑ Not very
confident
Deep dive: 201 7
Fundamentals
Handbook,
Chapter 39
❑ Confident 201 7 Fundamentals
Chapters
❑ Somewhat Handbook,
1 7 and 1 8
confident
❑ Not very
confident
Deep dive: 201 7
Fundamentals
Handbook, Chapters
3, 9, and 36
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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DOMAIN 2, TASKS A-J
Task E: Calculate head
loss through the critical
path.
❑ Confident 201 7 Fundamentals
❑ Somewhat Handbook,
Chapter 22
Task F: Calculate heat
loads for each assigned
space in the building.
❑ Confident
❑ Somewhat
Task G: Calculate the
building load heat loss
and gain.
❑ Confident
❑ Somewhat
Task H: Calculate external
static and total pressures
for air-distribution units and
specify in the equipment
schedule.
❑ Confident
❑ Somewhat
Task I: Calculate
ventilation rate
requirements by space
use, thermal comfort
parameters, and air quality
per applicable codes
and standards.
❑ Confident
❑ Somewhat
Task J: Design piping
system to account for
various fluid properties
(e.g., freeze protection,
fluid expansion
compensation, fluid
density, transfer capacity).
❑ Confident
❑ Somewhat
confident
❑ Not very
confident
confident
❑ Not very
confident
confident
❑ Not very
confident
confident
❑ Not very
confident
confident
❑ Not very
confident
confident
❑ Not very
confident
Deep dive: 201 7
Fundamentals
Handbook, Chapters
21 and 39
201 7 Fundamentals
Handbook, Chapters
1 7 and 1 8
Deep dive: 201 7
Fundamentals
Handbook, Chapters
1 4, 1 5, 1 6, and 39
201 7 Fundamentals
Handbook, Chapters
1 7 and 1 8
Deep dive: 201 7
Fundamentals
Handbook, Chapters
3, 9, 1 4, 1 5, 1 6,
and 36
201 7 Fundamentals
Handbook,
Chapter 21
Deep dive: 201 6
Systems and
Equipment
Handbook,
Chapter 21 ; 201 7
Fundamentals
Handbook,
Chapter 39
201 7 Fundamentals
Handbook, Chapters
9, 1 6, and 40
Deep dive: 201 7
Fundamentals
Handbook, Chapters
3 and 36
201 7 Fundamentals
Handbook, Chapters
3 and 22
Deep dive: 201 7
Fundamentals
Handbook, Chapters
9 and 31
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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DOMAIN 2
DOMAIN 2: DESIGN
CALCULATIONS PRACTICE
EXAM QUESTIONS
1.
CHECK ANSWERS
CLEAR ANSWERS
A l ou ver i s rated to resi st water penetrati on for veloci ti es u p to 1 000 fpm
(5. 1 m /s) an d has 70%
free area. Wh at i s the m axi m u m ai rflow that can
flow throu g h a l ou ver wi th an overal l area of 1 2 ft² (1 . 1 1 m ²) ?
2.
A.
3600 cfm (1 02 m ³/mi n)
B.
8400 cfm (238 m ³/mi n )
C.
1 2, 000 cfm (340 m³/mi n)
An exi sti ng bu i l di ng i s served by a chi ll er plant operati n g at delta T 1 0F
(5. 56 C) wi th total chi lled water fl ow 700 U . S. g pm (44. 1 6 L/s) . The
bu i l di ng owner deci des to repl ace the chi l ler pl an t wi th a new h i g h perform ance ch i l l er plant, whi l e m ai n tai n i n g th e same total cool i n g
capaci ty. The new chi l ler pl an t wi l l operate at delta T 1 4F (7. 78 C) . What
i s the TOTAL ch i l l ed water flow of th e new pu m p(s) ?
3.
A.
500 U . S. g pm (31 . 55 L/s)
B.
700 U . S. g pm (61 . 83 L/s)
C.
980 U . S. g pm (44. 1 6 L/s)
1 00 GPM (378 LPM) of water i s pu mped wi th a 2 H P base-m ou n ted pu m p
operati ng at 75% effi ci ency. Wh at i s the approxi mate head l oss on the system?
4.
A.
40 ft (1 20 kPa)
B.
60 ft (1 80 kPa)
C.
80 ft (240 kPa)
The preferred relati ve humidi ty ran g e for hu man h ealth and comfort i s
between _________.
A.
30 and 50%
B.
40 and 60%
C.
50 and 70%
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DOMAIN 2
5. When evaluating a system to recommend to a building owner who intends
to own and operate the building 20 years, which of the following systems
would have the lowest life-cycle cost ?
A. system A, which has an installed cost of $1 00,000 and an annual
operating and maintenance cost of $3,500
B. system B, which has an installed cost of $1 25,000 and an annual
operating and maintenance cost of $1 ,500
C. system C, which has an installed cost of $80,000 and an annual
operating and maintenance cost of $1 ,500 and estimated life span of
1 5 years
6. What is the criterion MOST used for louver sizing?
A. maximum free area
B. minimum static pressure drop
C. water penetration
7. In the formula for velocity,
V=Q/A, A represents which of the following?
A. airflow rate
B. cross-sectional area of duct
C. total pressure
8. A hot-water heating system is to be designed to operate between 1 20°F
and 1 80°F (49°C and 82°C). Which of the following should be avoided as
a piping material?
A. copper
B. steel
C. PVC
9. Which equation is used to calculate the time it takes for an incompressible
fluid in a horizontal, constant-area conduit to achieve steady flow?
A. unsteady Flow
B. Bernoulli
C. Poiseuille Flow
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CHECK ANSWERS
CLEAR ANSWERS
DOMAIN 2
1 0. When predi cti n g th e mean respon se of a l arg e grou p of peopl e accordi ng
to the ASH RAE therm al sen sati on scale, the
predicted mean vote
(PMV) i n dex i s u sed. I n the PMV equ ati on, L represents:
A.
acti vi ty l evel
B.
l en g th
C.
therm al l oad on the body
1 1 . Whi ch of th e fol l owi n g i s the MOST u nknown factor wh en performi ng l oad
cal cu lati ons?
A.
di m en si on s of th e bu i l di ng
B.
ski l l of bu i l der
C.
infiltration rates
1 2. When cal cu lati ng the al lowable ai r leakag e for each fan system , the
recom mend ed percentag e for su pply and retu rn du ctwork secti ons that
l eak di rectly to/from the su rrou ndi n g space i s whi ch of the foll owi ng ?
A.
2%
B.
3%
C.
5%
1 3. When u si ng th e Darcy-Wei sbach equ ati on and presenti ng i t in h ead or
speci fi c energ y form ,
g represents:
A.
accelerati on of g ravi ty
B.
u n i ts conversi on factor
C.
flu i d den si ty
1 4. When cal cu lati ng pressure drop, wh i ch of th e fol lowi ng i nform ati on i s
provided within the manufacturer’s data?
A.
flow rate
B.
h ead l oss from equ i pment
C.
valves and fi tti ng s
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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CHECK ANSWERS
CLEAR ANSWERS
DOMAIN 2
1 5. When com pl eti n g heating cal cu l ati ons, wh i ch of the fol l owi ng needs to be
taken i nto accou n t?
A.
heat gain from i n tern al equ i pment
B.
heat loss throu g h exteri or wall s
C.
solar heat g ai n throu g h exteri or g l azi ng
1 6. When cal cu lati ng the heat g ai n th rou g h an exteri or g l azi n g , i t i s MOST
i mportant to kn ow whi ch of the fol lowi ng ch aracteri sti cs?
A.
el evati on above sea l evel an d g lass thi ckness
B.
ori entati on and elevati on above sea level
C.
ori entati on and g lass thi ckness
1 7. Whi ch m on th i s u sed to determ in e th e ti me of year when the M AXI M U M
h eati n g l oad occu rs?
A.
the m on th wi th the h i g h est mean dry bu lb
B.
the m on th wi th the hottest m ean dry bu l b
C.
the m on th wi th the lowest mean dry bu lb
1 8. A space has a total exteri or wal l area of 1 200 ft² (1 1 1 m²) and an
i nsu l ati on val u e of R-1 8 (RSI 3. 1 7) . The desi g n ou tdoor h eati ng
tem peratu re i s 0° F (1 7. 8° C) and the i nteri or temperatu re i s 70° F
(21 . 1 ° C) . Wh at i s the approxi m ate total heat requ i red to offset the l oss
throu g h th e wall ?
A.
2. 2 M BH (0. 64 kWh)
B.
3. 5 M BH (1 . 03 kWh )
C.
4. 7 M BH (1 . 38 kWh )
1 9. Whi ch of th e fol l owi n g statements i s MOST correct when esti mati ng h eat
l oss th rou g h com pl etel y bel ow-g rade stru ctu res?
A.
All bel ow-g rade su rfaces are treated i den ti call y.
B.
H eat fl ow paths can be u sed to fi nd the steady-state h eat loss to the
g rou nd su rface.
C.
The exteri or ai r tem peratu re i s cri ti cal to determ i n i ng the heat loss.
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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CHECK ANSWERS
CLEAR ANSWERS
DOMAIN 2
20. When calculating daily temperatures, which of the following is the MOST
important to take into consideration?
A. daylight savings time
B. local time
C. solar time
21 . A new duct-mounted coil is inserted into an existing duct system with a
total system airflow of 5,000 cfm (2.36 m³/s). The existing system is
operating at a total static pressure of 1 .5” w.c. (373 Pa) and the additional
coil will add 0.3” w.c. (74 Pa) to the total static pressure. The existing
supply fan motor is operating at 1 236 RPM. What will the approximate
resulting fan speed need to be to maintain the same total system airflow?
A. 1 1 29 RPM
B. 1 353 RPM
C. 1 658 RPM
22. At diverging transitions of a fan/duct system, which of the following
is correct?
A. Absolute static pressure can decrease.
B. Absolute total pressure increases.
C. Velocity pressure decreases.
23. Evaporative heat loss from skin depends on:
A. amount of moisture on the skin
B. clothing area factor
C. the surface area of the skin
24. When using equations for estimating heat transfer coefficient ( ℎ푐 ), the
effective heat transfer area may be inaccurate for whom?
A. seated and reclining persons with moving air
B. standing persons in moving air
C. walking and active persons in still air
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
47
CHECK ANSWERS
CLEAR ANSWERS
DOMAIN 2
25. What concept describes the proper ventilation rate averaging process.
CHECK ANSWERS
CLEAR ANSWERS
A. active
B. effective
C. efficient
26. Flow devices with gradual contours are subject to separation that is more
difficult to predict. Which of the following are used to reduce the loss in
expansion?
A. diffuser
B. splitter
C. stall
27. In metallic pipe when stress calculations are required, an area of concern
is which of the following?
A. external pressure stress
B. lateral stress caused by pressure and weight
C. stress from expansion and contraction
28. Using density to determine glycol concentration is unsatisfactory
because:
A. Density measurements are not temperature sensitive.
B.
Inhibitor concentrations can change density.
C. Propylene glycol values exhibit a maximum at 50 to 55%
concentration.
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
48
DOMAIN 3
SECTION 3: DOMAIN 3,
PROCEDURAL
Overview
Domain 3 is focused on the procedures that HVAC designers execute. In this
Domain, you deal with the practical considerations of taking your design from
paper to reality. The Tasks in this Domain will test your abilities to:
• Analyze your design, or another’s, for conformance with codes, standards,
and regulations.
• Review shop drawings to ensure that the materials to be installed meet the
design intent.
• Perform field reviews during construction and to verify/document as-built
conditions.
• Review and respond to requests for information (RFI) and other consultantcontractor interactions.
The procedural work that Domain 3 concerns itself with is paramount to
achieving the goals set out in Domain 1 and 2. As a designer, you do not just
send your designs out into the ether, never to be heard from again. Carefully
following proper procedures will allow your design to be built to your
specifications.
Once you are satisfied that you are sufficiently competent in all of the Tasks
in Domain 3, move on to Domain 4.
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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DOMAIN 3, TASKS A-K
Quick Quiz, Domain 3, Tasks A-K
Now, let’s test your knowledge of some key terms/concepts found in Doma
3,
Tas ks
o p ti o n
A- K.
fro m
F o r e ach
th e
ch o i ce s
d e fi n i ti o n
o r co n ce p t,
s e l e ct
an d
wri te
in
th e
in
co rre ct
p ro vi d e d .
TERMS
DEFINITIONS
As - bu i l t
1 .
____________________ i s
o wn e r wh o
C xA
th e
l e ad s ,
p l an s ,
co m m i s s i o n i n g
co m m i s s i o n i n g
an
e n ti ty
s ch e d u l e s ,
te am
to
i d e n ti fi e d
an d
i m pl e m e n t
by
th e
co o rd i n ate s
th e
p ro ce s s .
Faci l i ty g u i d e
2.
____________________ i s
a b as i c
bu i l d i n g
s ys te m s
I n ve s ti g ati o n
d e s cri p ti o n
an d
M o n i to ri n g
p ro ce d u re s
Owner’s project
co n d i ti o n s ,
re q u i re m e n ts
to
p l an
co n fi rm e d
s e t p o i n ts ,
p ro ce d u re s
wi th
faci l i ty o pe rati n g
s ch e d u l e s ,
p ro p e rl y
g e n e ral
o p e rate
an d
th e
o pe rati n g
faci l i ty.
(OPR)
3.
Room
an d
o p e rati n g
cl e an l i n e s s
Com m i ssi on i n g
ce rti fi cate s
an d
a co m p l e te
d rawi n g s ,
pi pi n g ,
d o cu m e n ts
warran ti e s
sh ou l d
i n cl u d e
o f s ys te m
co m p l e ti o n
wi th
s e t o f ____________________
s u b m i tte d
p l u m bi n g ,
fro m
co n tro l ,
m e ch an i cal ,
an d
fi re
e l e ctri cal ,
p ro te cti o n
co n tracto rs .
4.
____________________ i s
a d o cu m e n t
th e
o f a p ro j e ct an d
fu n cti o n al
e xp e ctati o n s
5.
s ys te m
p aram e te rs
we e ks
be
u sed
In
th e
an d
u ses
o r d ata l o g g e rs
o ve r ti m e
an d
an al yz e
to
th e
fi n al
s ys te m
d ata d ays
co m m i s s i o n i n g
re p o rt,
or
if
re q u i re d ,
b u i l t re p o rt
co m p l e ti o n
m u s t be
o f te s ti n g
an d
d u ri n g
i n s tal l ati o n
a
p ro vi d i n g
ce rti fi e d
as -
of
d o cu m e n tati o n
i n cl u d e d .
____________________ p h as e
d e tai l e d
te s ti n g
bu i l d i n g
re co rd
th e
th e
o p e rate d .
____________________ i s
Th e
th at d e tai l s
l ate r.
co n s tru cti o n
7.
o f h o w i t wi l l
____________________ te s ti n g
au to m ati o n
6.
re q u i re m e n ts
i n te rvi e ws
an d
wi th
d o cu m e n tati o n
p e rfo rm an ce ,
an d
re co m m e n d e d
i n cl u d e s
m ai n te n an ce
o f e xi s ti n g
i d e n ti fi cati o n
an d
m o re
pe rs o n n e l ,
bu i l d i n g
an al ys i s
of
ch an g e s .
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
50
CHECK ANSWERS
DOMAIN 3, TASKS A-K
Self-assessment
What’s your baseline?
Read and consider each Task and rank your confidence level. Then consult
the resources for each Task (especially those which you marked somewhat
or not very confident). You might want to skim the resources on this first
pass. Record notes in the last column about topics you need to spend
additional time studying, marking chapters and page numbers where
appropriate to guide you. You’ll use these notes to create your Study Map
after you have completed your Self-assessment of all four Domains.
NOTE: This is the only set of Tasks for Domain 3. Answer the Practice Exam
Questions that follow for Domain 3 before moving on to Domain 4.
How confident are you in your knowledge,
skills, and abilities in these job Tasks
Task A: Analyze buildings, ❑ Confident
building designs, or HVAC ❑ Somewhat
plans for compliance with
confident
applicable codes,
standards, and regulations. ❑ Not very
confident
Task B: Apply Building
Information Modeling (BIM)
standards throughout
drawing production.
❑ Confident
❑ Somewhat
Task C: Review shop
drawings and equipment
submittals for compliance
with contract documents.
❑ Confident
❑ Somewhat
Task D: Interpret design
documents during
bidding/tender and
construction phases.
❑
❑
confident
❑ Not very
confident
❑
❑
confident
Not very
confident
Confident
Somewhat
confident
Not very
confident
Task-by-Task
My Notes (Topics I Need to Spend
Resource Guide
time Studying)
201 7 Fundamentals
Handbook,
Chapter 40
Deep dive: 201 6
Systems and
Equipment
Handbook, Chapter
52; 201 9 Applications
Handbook, Chapters
44 and 66
201 7 Fundamentals
Handbook,
Chapter 1 9
Deep dive: 201 9
Applications
Handbook, Chapters
41 and 60
201 9 Applications
Handbook,
Chapter 44
201 9 Applications
Handbook,
Chapter 44
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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DOMAIN 3, TASKS A-K
Task E: Review and
comply with HVAC codes
and standards.
❑ Confident 201 7 Fundamentals
❑ Somewhat Handbook,
Chapter 40
Task F: Verify and
document as-built field
conditions for projects in
construction.
❑ Confident
❑ Somewhat
Task G: Verify and
document as-built field
conditions for existing
structures.
❑
❑
Task H: Perform periodic
field investigations (e.g.,
punch-lists, quality control,
shop drawings).
❑
❑
Task I: Perform review of
Request for Information
(RFI) and incorporate into
bidding/tender documents.
❑
❑
Task J: Prepare HVAC
documentation for building
permit application and
coordinate with Authority
Having Jurisdiction (AHJ).
❑
❑
Task K: Incorporate field
“as - bu i l t” d ocu m en ts i n to
final documents.
❑
❑
confident
❑ Not very
confident
❑
❑
❑
❑
❑
❑
confident
Not very
confident
Confident
Somewhat
confident
Not very
confident
Confident
Somewhat
confident
Not very
confident
Confident
Somewhat
confident
Not very
confident
Confident
Somewhat
confident
Not very
confident
Confident
Somewhat
confident
Not very
confident
Deep dive: 201 6
Systems and
Equipment
Handbook, Chapter
52; 201 9 Applications
Handbook,
Chapter 66
201 9 Applications
Handbook,
Chapter 44
201 9 Applications
Handbook,
Chapter 60
201 9 Applications
Handbook,
Chapter 44
201 9 Applications
Handbook,
Chapter 44
201 9 Applications
Handbook,
Chapter 44
201 9 Applications
Handbook,
Chapter 44
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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DOMAIN 3
DOMAIN 3: PROCEDURAL
PRACTICE EXAM QUESTIONS
1.
CHECK ANSWERS
CLEAR ANSWERS
Whi ch of th e fol l owi n g i s devel oped wi th th e help of u sers, occu pan ts, an d
owners?
2.
A.
basi s of desi g n (BOD)
B.
cu rren t faci li ty requ i rem ents (CFR)
C.
exi sti n g bu i ldi ng commissi oni ng (EBCx) process
What i s the bu i ldi n g desi g n and docu mentation m ethodol og y that rel i es
on th e creati on and col lecti on of i nterrel ated, com pu tabl e i n form ati on
abou t a bu i ldi ng proj ect th at i s a reliabl e, coordin ated, an d in tern al ly
consi sten t dig ital representati on of the bu i l di ng ?
3.
4.
A.
bu i l di ng i n formati on man ag ement (BI M)
B.
bu i l di ng i n formati on m od el i n g (BI M)
C.
com pu ter-ai ded desi g n (CAD) systems
A system s man u al contai ns whi ch one of the fol lowi n g i tems?
A.
cu rren t faci li ty requ i rem ents (CFR)
B.
desi g n cal cu l ati on s
C.
owner’s project requirements (OPR)
I n a si tu ati on of di spu tes or am bi g u i ti es, the h i g h est pri ori ty docu m en t to
refer to i s whi ch of the fol lowi ng ?
A.
contract
B.
project m an u al
C.
drawi n g s
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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DOMAIN 3
5. A planned renovation of a 2,41 0 ft² (224 m²) retail space with a 40-occupant
capacity is located on the second floor of a 5-story commercial building.
Calculate the approximate minimum outdoor air requirement if the people
outdoor air rate is 7.5 cfm/person (3.8 l/s-person) and the area outdoor air
rate 0.1 8 cfm/ft² (o.9 l/s-m²).
A. 489 cfm (230.8 l/s)
B. 689 cfm (325.3 l/s)
C. 734 cfm (353.6 l/s)
6. In conducting validations of the accuracy of the as-built plan for existing
buildings, the FIRST step is to:
A. check the air-distribution side
B. identify equipment room locations
C. verify the actual equipment versus previous submittals
7.
When the actual installation deviates from the issued “For Construction
Plan,” what project document should be verified to reconcile?
A. approved submittals
B. meeting minutes
C. specifications
8. During the project implementation process, which of the following is NOT
a main responsibility of an HVAC designer?
A.
monitor the HVAC contractor’s daily work
B. review and approve submittals
C. validate Requests for Information (RFI)
9. Which of the following is a valid reason for a contractor to submit a
Request for Information (RFI) during the construction process?
A. The contractor failed to include a portion of the installation as part of
their bid.
B. There has been a field-directed change to the documents, and the
contractor is requesting additional compensation.
C. There is conflicting information between two (2) separate trades
drawings.
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
54
CHECK ANSWERS
CLEAR ANSWERS
DOMAIN 3
1 0. A m ech ani cal permi t appl i cati on COMM ON LY requ i res wh i ch docu men t?
A.
equ i pm ent warranty
B.
H VAC plans
C.
sh op drawi ng s
1 1 . As-bu i lt drawi n g s provi ded by the contractor serve whi ch of the fol lowi ng
pu rposes?
A.
al l ow the H VAC desi g ner to revi ew proposed su bsti tu ti ons pri or to
i n stal l ati on
B.
docu men t ch ang es to the desi g n made throu g hou t constru cti on
C.
en su re that n o confl i cts exi st between all i nstal li ng contractors
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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CHECK ANSWERS
CLEAR ANSWERS
DOMAIN 4, TASKS A-J
SECTION 4.1 : DOMAIN 4,
COORDINATION, TASKS A-J
Overview
An HVAC designer does not exist in a vacuum. Your work affects, and is
affected by, every system and assembly in the building.
The Tasks in Domain 4 measure your ability to coordinate with other
individuals or teams on the project and to ensure that your design meets the
conditions you have been presented. These Tasks also allow you
opportunities to provide input to the other design professionals as it relates to
your systems.
Tasks A-J will test your ability to:
• Assist in the development of the basis of design (BOD) document with the
other consultants and owner.
• Coordinate space and structural requirements for your HVAC systems.
• Analyze architectural documents to establish your design concept and
calculations (Domain 1 & 2), as well as to provide input that may reduce
overall energy usage and occupant comfort.
• Collaborate with other team members on the HVAC design team.
• Most importantly, collaborate with other design disciplines to ensure the
health and safety of the building occupants.
Design professionals from other disciplines may not be well versed in the
requirements and constraints of your work. Your competency in this Domain
will allow you to be an effective advocate for your design and to ensure that
your design meets the requirements of the other disciplines.
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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DOMAIN 4, TASKS A-J
Quick Quiz, Domain 4, Section 4.1 , Tasks A-J
Now, let’s test your knowledge of some key
term s/con cepts fou n d i n D om ai n
4, Tasks A- J . For each d efi n i ti on or con cept, sel ect an d wri te i n th e correct
opti on from th e ch oi ces provi d ed .
TERMS
DEFINITIONS
Basi s of d esi g n
1 .
____________________ i s u sed to resi st th e
passag e of sm oke.
D esi g n param eters
2.
D esi g n team
to eval u ate al l revi ew fi n d i n g s wi th th e
Owner’s project
____________________ an d see th at th e respon si bl e
team m em ber i m pl em en ts th e approved d eci si on s.
req u i rem en t (OP R)
Perform an ce
I t i s th e respon si bi l i ty of th e own er or proj ect m an ag er
3.
Som e d esi g n revi ews u se ____________, g i vi n g 1 0
to 20% of th e d rawi n g s an d speci fi cati on s for an i n -
req u i rem en ts
d epth revi ew; i f on l y m i n i m al i ssu es are i d en ti fi ed , th e
own er accepts th e su bm i ssi on .
Sam pl i n g
Sm oke d am per
4.
Th e ____________________ i s a d ocu m en t th at
record s th e con cepts, cal cu l ati on s, d eci si on s, an d
Stru ctu ral en g i n eer
prod u ct sel ecti on s u sed to m eet th e OPR an d to
sati sfy appl i cabl e reg u l atory req u i rem en ts, stan d ard s,
Ven ti l ati on
an d g u i d el i n es.
5.
Al l l oad s on th e stru ctu re sh ou l d be com m u n i cated to
an d coord i n ated wi th th e ____________________.
6.
Th e ____________________ i s g en eral l y a set of
con ci se obj ecti ve q u al i tati ve statem en ts, each wi th
on e or m ore q u an ti tati ve perform an ce m etri cs or
cri teri a.
7.
Captu re vel oci ty, d u ct m ateri al , an d perti n en t d u ct
fi tti n g s an d fabri cati on are a few of th e
____________________ n ecessary for exh au st
system s, especi al l y th ose servi n g fu m e exh au st, d u st,
an d /or parti cl e col l ecti on to fu n cti on properl y,
effi ci en tl y, an d per appl i cabl e cod es.
8.
____________________ an d pl u m bi n g d esi g n com e
from th e d esi g n bu i l d i n g popu l ati on , an d are
som ewh at i n d epen d en t of th e h i erarch y of on e
system i n fl u en ci n g an oth er.
9.
Th e com m i ssi on i n g obj ecti ve focu ses on d ocu m en ted
con fi rm ati on th at a faci l i ty fu l fi l l s th e speci fi ed
__________________ for th e bu i l d i n g own er,
occu pan ts, an d operators.
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
57
CHECK ANSWERS
DOMAIN 4, TASKS A-J
Self-assessment
What’s your baseline?
Read and consider each Task and rank your confidence level. Then consult
the resources for each Task (especially those which you marked somewhat
or not very confident). You might want to skim the resources on this first
pass. Record notes in the last column about topics you need to spend
additional time studying, marking chapters and page numbers where
appropriate to guide you. You’ll use these notes to create your Study Map
after you have completed your Self-assessment of all four Domains.
How confident are you in your knowledge,
skills, and abilities in these job Tasks?
Task A: Assist in the
❑ Confident
development of the basis of ❑ Somewhat
design (BOD).
confident
❑ Not very
confident
Task B: Review HVAC
drawings with
Commissioning Authority
(CxA0).
❑ Confident
❑ Somewhat
Task C: Coordinate space
requirements for HVAC
equipment placement with
other design team
members.
❑ Confident
❑ Somewhat
Task D: Modify the HVAC
design documents concept
based on the outcome of
the design team reviews.
❑
❑
Task E: Coordinate
systems expansion
compensation design with
structural engineer and
piping vendor (e.g., thrust
blocks, expansion joints,
anchor points).
❑
❑
confident
❑ Not very
confident
❑
❑
❑
confident
Not very
confident
Confident
Somewhat
confident
Not very
confident
Confident
Somewhat
confident
Not very
confident
Task-by-Task
Resource Guide
201 9 Applications
Handbook, Chapters
44 and 60
Deep dive: 201 6
Systems and
Equipment
Handbook, Chapter 1
201 9 Applications
Handbook,
Chapter 44
Deep dive: 201 9
Applications
Handbook,
Chapter 60
201 9 Applications
Handbook,
Chapter 44
My Notes (Topics I Need to Spend
time Studying)
201 9 Applications
Handbook,
Chapter 44
201 6 Systems and
Equipment
Handbook,
Chapter 46
Deep dive: 201 9
Applications
Handbook,
Chapter 44
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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DOMAIN 4, TASKS A-J
Task F: Analyze
architectural plans,
sections, and elevations for
use in HVAC design.
❑ Confident 201 9 Applications
Chapters
❑ Somewhat Handbook,
44 and 45
Task G: Comply with client
specifications and
performance requirements
to determine mechanical
designs.
❑ Confident 201 9 Applications
❑ Somewhat Handbook,
Chapter 44
Task H: Collaborate in the
development of HVAC
systems and design
parameters.
❑ Confident 201 6 Systems and
Handbook,
❑ Somewhat Equipment
Chapters 1 and 50
Task I: Review
architectural life safety plan
relative to mechanical plan
and apply fire and smoke
damper requirements.
❑ Confident 201 9 Applications
Chapters
❑ Somewhat Handbook,
44 and 54
❑
❑
❑
❑
confident
Not very
confident
Deep dive: 201 9
Applications
Handbook,
Chapter 60
confident
Not very
confident
confident
Not very
confident
201 9 Applications
Handbook,
Chapter 44
confident
Not very
confident
Task J: Coordinate with life ❑ Confident 201 9 Applications
and safety engineer to
Chapters
❑ Somewhat Handbook,
44
and
54
design the smoke
confident
management and
dive: 201 9
❑ Not very Deep
ventilation system per fire
Applications
confident
code and regulation.
Handbook,
Chapter 60
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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DOMAIN 4, TASKS K-U
SECTION 4.2: DOMAIN 4,
COORDINATION, TASKS K-U
Overview
As mentioned earlier, an HVAC designer does not exist in a vacuum, and you
are, unfortunately, unable to design everything with which your systems need
to interact.
The equipment in your design requires electricity, water and drainage,
structural support, and sound or vibration isolation. Typically, these are all
achieved by different disciplines, and they require input from you to ensure
that their work suits the needs of your design, and in many cases the reverse
is also true. Often you are constrained by the power that is available to the
building, or limitations of the existing structure will not support your equipment
and distribution.
Domain 4 is a measure of the human touch of design. Topics to be
considered include the following:
• Can you communicate appropriately with others and speak their language?
• Can you consider other designers needs and convince them to give
consideration to yours?
While you may be very skilled in the Tasks of Domains 1 -3, they matter very
little if you have insufficient power to your chiller because you did not
articulate your needs to the electrical engineer. Likewise, no one will be
particularly impressed with the accuracy of your calculations if the owner is
now paying a small fortune for a structural change because you failed to
properly coordinate your duct routing.
As an HVAC designer, you are thoroughly involved from the very beginning,
all the way to the end. While you may be part of a large team and focused
only on a small portion of the design, your efforts and those of your team
permeate throughout the entire project. The success of the project is a
measure of your individual skill as a designer and your ability to interact with
everyone else involved.
Once you are satisfied that you are sufficiently competent in all of the Tasks
in Domain 4, move on to the Study Map.
’
CERTIFICATION STUDY GUIDE | CERTIFIED HVAC DESIGNER (CHD)
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DOMAIN 4, TASKS K-U
Quick Quiz, Domain 4, Section 4.2, Tasks K-U
Now, l et’s test your knowledge of some key terms/concepts found in Domain
4, Tasks K-U. For each definition or concept, select and write in the correct
option from the choices provided.
TERMS
DEFINITIONS
Construction
schedule
1 . ____________________ is a unit of real electrical power,
equal to the power developed in a circuit by a current of 1 A
flowing through a potential difference of 1 V.
Cycle
Domestic
water system
Electrical
designers
Medium life
to live
Peer-to-peer
Snubber
Trade
contractors
UFAD zones
Watt (W)
2. During the commissioning process evaluation, the
commissioning authority should meet briefly with the owner;
general, controls, mechanical, and electrical contractors;
and mechanical and ____________________ to discuss
the commissioning process.
3.
The CxA’s design review is not intended to replace
____________________ design reviews that check for
accuracy and completeness of the design and calculations.
4. The ____________________ is the part of the fundamental
waveform where the electrical potential goes from zero to a
maximum to zero to a minimum, and back to zero again.
5. The acoustic characteristics of a room are considered to
____________________ if they have little sound
absorption.
6. The CxA works with the contractors and construction
manager to coordinate the commissioning schedule and
ensure that commissioning activities are integrated into the
master ____________________.
7. Approximate methods have been used by energy modelers,
such as raising the thermostat set point in the
____________________ to represent a higher average air
temperature or representing the actual zone with two
stacked zones in the model.
8. During predesign and design, the list of areas to be
commissioned may be general and include such options as
electrical lighting controls, emergency power, and
____________________.
9. ____________________ of specialty or complex systems
or designs should review commissioning requirements and
performance criteria of their systems for coordination,
schedule, and cost implications.
1 0. ____________________ is a device made of steel-housed
resilient bushings arranged to prevent equipment from
moving beyond an established gap.
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CHECK ANSWERS
DOMAIN 4, TASKS K-U
Self-assessment
What’s your baseline?
Read and consider each Task and rank your confidence level. Then consult
the resources for each Task (especially those which you marked somewhat
or not very confident). You might want to skim the resources on this first
pass. Record notes in the last column about topics you need to spend
additional time studying, marking chapters and page numbers where
appropriate to guide you. You’ll use these notes to create your Study Map
after you have completed your Self-assessment of all four Domains.
How confident are you in your knowledge,
skills, and abilities in these job Tasks?
Task K: Coordinate with
❑ Confident
other design team
❑ Somewhat
members during each
confident
design phase (e.g.,
❑
Not very
architects, structural
confident
designers, plumbing
designers, electrical
designers).
Task L: Coordinate HVAC ❑ Confident
implications for the building ❑ Somewhat
electrical loads and
confident
electrical space mechanical
requirements with electrical ❑ Not very
confident
design team members.
Task M: Coordinate with
structural engineer for
HVAC requirements (e.g.,
duct and piping runs,
anchorage, seismic
bracing, sound isolation,
support requirements,
vibration).
Task N: Coordinate with
project design and
construction schedules.
❑ Confident
❑ Somewhat
confident
❑ Not very
confident
Task-by-Task
Resource Guide
201 9 Applications
Handbook,
Chapter 44
My Notes (Topics I Need to Spend
time Studying)
201 9 Applications
Handbook,
Chapter 44
Deep dive: 201 9
Applications
Handbook, Chapters
57 and 60
201 9 Applications
Handbook, Chapters
44, 49, and 56
Deep dive: 201 9
Applications
Handbook,
Chapter 60
❑ Confident 201 9 Applications
❑ Somewhat Handbook,
Chapter 44
confident
❑ Not very
confident
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DOMAIN 4, TASKS K-U
Task O: Coordinate
electrical requirements for
HVAC equipment.
❑ Confident 201 9 Applications
Chapters
❑ Somewhat Handbook,
44 and 57
Task P: Coordinate
requirements of HVAC
system for domestic water
and waste with plumbing
designer.
❑ Confident
❑ Somewhat
Task Q: Coordinate with
acoustical engineer for
selection of ventilation
equipment including sizing
of ventilation distribution
and air-handling equipment
to meet designated sound
pressure levels.
❑
❑
Task R: Coordinate with
energy modeler for HVAC
system input.
❑ Confident
❑ Somewhat
Task S: Coordinate site
piping and utility
requirements with civil
engineer.
❑ Confident
❑ Somewhat
Task T: Coordinate with
vendors to prepare
equipment schedules.
❑
❑
Task U: Review drawings
and identify potential
obstructions that may
impact the HVAC system
(e.g., structural, fire
proofing, lighting,
sprinklers, walls).
❑
❑
confident
❑ Not very
confident
❑
❑
confident
Not very
confident
Confident
Somewhat
confident
Not very
confident
confident
❑ Not very
confident
❑
❑
❑
confident
Not very
confident
Confident
Somewhat
confident
Not very
confident
Confident
Somewhat
confident
Not very
confident
Deep dive: 201 9
Applications
Handbook,
Chapter 60
201 9 Applications
Handbook,
Chapter 44
201 9 Applications
Handbook,
Chapter 49
Deep dive: 201 7
Fundamentals
Handbook, Chapters
3, 8, 9, 37; 201 9
Applications
Handbook, Chapter
44 and 60
201 9 Applications
Handbook,
Chapter 44
Deep dive: 201 7
Fundamentals
Handbook, Chapter
1 9; 201 9 Applications
Handbook,
Chapter 60
Deep dive: 201 9
Applications
Handbook,
Chapter 44
Deep dive: 201 9
Applications
Handbook,
Chapter 44
Deep dive: 201 9
Applications
Handbook,
Chapter 44
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DOMAIN 4
DOMAIN 4: COORDINATION
PRACTICE EXAM QUESTIONS
1.
CHECK ANSWERS
CLEAR ANSWERS
What i s the docu men t that records th e concepts, cal cu l ati ons, deci si on s,
and product selections used to meet the owner’s project requirements
(OPR) ?
2.
A.
basi s of desig n (BOD)
B.
cu rren t faci li ty requ i rem ents (CFR)
C.
system s m an u al
When i s the M OST appropri ate ti me to beg i n th e com mi ssi oni ng process
on a proj ect?
A.
com mi ssi oni n g i s u n n ecessary i f the desi g ner has completed thei r
work properly
B.
du ri n g th e predesi g n phase, when the scope and i n ten t h ave been
establ i sh ed
C.
3.
when the project i s com pleted and perform ance n eeds to be veri fi ed
When coordi n ati n g wi th archi tectu ral m em bers of the desi g n team, what
rel evant i n form ati on shou l d th e H VAC desi g n er provi de as i t rel ates to
H VAC equ i pment placem ent?
4.
A.
equ i pm ent tonnag e
B.
power an d voltag e requ i rem ents
C.
servi ce cl earances an d cl earance to com bu sti bles
Whi ch of th e fol l owi n g statem ents appl i es to the rol e that the desi g n team
plays i n th e commissi oning process?
A.
I t i s the responsi bi lity of the owner or project m an ag er to evalu ate all
revi ew fi ndi ng s wi th the desi g n team.
B.
Th e commi ssi oni ng professi onal i s u l ti m atel y respon si bl e for desi g n.
C.
Th e desi g n team makes recommendati ons to faci l i tate com mi ssi oni ng
an d i m prove bu i l di ng performance.
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DOMAIN 4
5. Which expansion control system depends on slipping or sliding surfaces
to accommodate movement and requires some type of seals or packing?
A. ball joints
B. expansion joints
C. expansion loops
6. Which drawings should be analyzed FIRST prior to preparing duct or pipe
routes for interferences and to ensure that all HVAC components fit in the
available service spaces?
A. architectural
B. civil
C. structural
7. When initiating the HVAC design process, to ensure a successful design,
which documents should the HVAC designer refer to FIRST?
A. applicable codes and standards
B. ASHRAE handbooks
C. client specifications and basis of design (BOD)
8. Which of the following design parameters are most likely to affect yearround energy usage when selecting direct-expansion (DX) coils?
A. air-side
friction loss
B. enclosure sweat
C. internal refrigerant pressure drop
9. When the duct layout for a proposed design is complete, the HVAC
designer should check the ______ found in the _______ to ensure that
the integrity of all fire-rated assemblies has been maintained.
A. fire damper shop drawings; fire suppression drawings
B. SMACNA standards; local fire code
C. wall construction schedules; architectural drawings
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CHECK ANSWERS
CLEAR ANSWERS
DOMAIN 4
1 0. The H VAC desi g n er shou l d coordi nate wi th wh i ch desi g n professi on al to
ensu re that th e smoke m an ag em en t an d ven ti l ati on system meets
rel evant fi re code?
A.
ci vi l en g i neer
B.
el ectri cal en g i n eer
C.
l i fe safety eng i neer
1 1 . Constru cti on su bm i ttal s MOST often are:
A.
presen ted to the con su l tant to rem ove all responsi bi li ty an d liabi li ty
from th e contractor
B.
revi ewed by the desi g n team and the commi ssi oni ng ag ent to veri fy
g eneral con form an ce wi th the desi g n intent
C.
a way to offl oad desi g n work from the con su l tan ts to the contractor
1 2. What type of proj ect deli very i s concerned wi th all aspects of bu i l di ng
perform ance, bu t sti l l needs to coordi nate th e different bu i l di ng systems to
avoi d rework.
A.
i nteg rated
B.
n on com pou n d
C.
sequ enti al
1 3. I n the equ ati on for determ ini ng th e desi g n wi n d pressu re for lou vers,
푅ℎ ,
represen ts:
A.
extern al pressu re coeffi ci ent at mean roof h ei g h t
B.
veloci ty pressu re at m ean roof heig ht
C.
volu m e of air fl ow at m ean roof heig ht
1 4. Whi ch of th e fol l owi n g i s a com m i ssi on i n g acti vi ty com pleted by the CxA?
A.
bu dg et developm ent
B.
establ i sh ment of own er requ i rem ents
C.
su bm i ttal revi ews
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CHECK ANSWERS
CLEAR ANSWERS
DOMAIN 4
1 5. The el ectri cian eng i n eer has provi ded th e H VAC desi g ner wi th a
CHECK ANSWERS
CLEAR ANSWERS
m axi m u m power rati ng i n Kw for a parti cu l ar servi ce. Wh i ch formu l a
wou l d be u sed to determ i ne the power con su m pti on of th e equ i pm ent?
A.
am p = power x vol ts
B.
power = vol ts x amps
C.
power = vol ts / am ps
1 6. Wh en desi gn i n g a coolin g tower an d associ ated pi pi n g , what i n formati on
sh ou l d th e H VAC desi g ner provi de to th e plu m bi ng desi g ner?
A.
desi g n temperatu res
B.
m akeu p water requ i rem ents
C.
rate of heat rej ecti on and pu m p fl ow
1 7. I n Phase 2 of the I n teg rated Proj ect Deli very (I PD) process, what i s the
rol e of th e H VAC desi g ner?
A.
assist in assembling the owner’s project requirements (OPR)
B.
coordi nate servi ce requ i rements wi th el ectri cal desi g n team
C.
produ ce bu i l di n g l oad cal cu l ati ons
1 8. An H VAC desi g ner sh ou ld provi de whi ch i nform ati on to the bu i l di n g
m odel er?
A.
equ i pm ent stru ctu ral l oad
B.
l i teratu re abou t th e DOE-2 Alg ori thm
C.
U -factor for
fenestration
1 9. Wh at sh ou l d the H VAC desi g ner coordi nate wi th th e ci vi l eng i neer?
A.
i ncom i ng spri nkler servi ce
B.
pi pi ng for a remote fl u i d cool er
C.
u n derg rou n d el ectri cal du ct
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DOMAIN 4
20. Having selected HVAC equipment with the assistance of the vendor,
where is the BEST location for the relevant performance information?
CHECK ANSWERS
CLEAR ANSWERS
A. equipment details
B. equipment schedule
C. equipment shop drawings
21 . Who is responsible for reviewing architectural, structural, plumbing, and
electrical drawings for potential interference with the HVAC system?
A. authority having jurisdiction (AHJ)
B. HVAC designer
C. mechanical contractor
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MY CHD CERTIFICATION EXAM
STUDY MAP
Task Notes
Where should I focus my time when studying for the
CHD exam?
The tables that follow organize and record the Tasks and topics you need to
focus upon as you prepare and study for the CHD exam (the responses you
provided in the Domain review populated here). Add additional notes here as
needed and use this to create a Study Plan which follows.
DOMAIN 1 : SYSTEM DESIGN
ADDITIONAL NOTES
Section 1 .1 , Tasks A-F
Task A
Task B
Task C
Task D
Task E
Task F
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Section 1 .2, Tasks G-L
Task G
Task H
Task I
Task J
Task K
Task L
Section 1 .3, Tasks M-R
Task M
Task N
Task O
Task P
Task Q
Task R
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Section 1 .4, Tasks S-Z
Task S
Task T
Task U
Task V
Task W
Task X
Task Y
Task Z(1 )
Task Z(2)
Task Z(3)
Task Z(4)
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DOMAIN 2: DESIGN CALCULATIONS
ADDITIONAL NOTES
Task A
Task B
Task C
Task D
Task E
Task F
Task G
Task H
Task I
Task J
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DOMAIN 3: PROCEDURAL
ADDITIONAL NOTES
Task A
Task B
Task C
Task D
Task E
Task F
Task G
Task H
Task I
Task J
Task K
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DOMAIN 4: COORDINATION
ADDITIONAL NOTES
Section 4.1 , Tasks A-J
Task A
Task B
Task C
Task D
Task E
Task F
Task G
Task H
Task I
Task J
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Section 4.2, Tasks K-U
Task K
Task L
Task M
Task N
Task O
Task P
Task Q
Task R
Task S
Task T
Task U
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Study Plan
How do I plan my time leading up to my test date?
Now, take this time to map your study plan, week by week. We’ve suggested
a 6-week schedule here, which you can adjust up or down depending on
when your exam is scheduled. For each week, note which Domain(s) and
Task(s) you plan to focus on, taking into consideration the weight of each
Domain (% of questions) and where you self-identified your gaps. For
example, Domain 1 is 40% of the exam, and if you identified that you need to
focus on studying 20 of the 29 Tasks, you may wish to break Domain 1 up
into several weeks of study. If you don’t know the exact date of your exam,
leave the dates blank; you can add that information in when you determine
your test date.
STUDY CALENDAR
EXAM DATE:___________
Week 1
Dates: __________
Domain(s): ______________________
Task(s): ________________________
General Notes:
Week 2
Dates: __________
Domain(s): ______________________
Task(s): ________________________
General Notes:
Week 3
Dates: __________
Domain(s): ______________________
Task(s): ________________________
General Notes:
Week 4
Dates: __________
Domain(s): ______________________
Task(s): ________________________
General Notes:
Week 5
Dates: __________
Domain(s): _____________________
Task(s): _______________________
General Notes:
Week 6
Dates: __________
Domain(s): ________________________
Task(s): __________________________
General Notes:
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PRACTICE EXAM QUESTIONS:
ANSWER KEY
NOTE: In the following answers to the practice exam questions, the
information in the parentheticals provide a location to the information related
to the correct answer. Here is the key to use in order to decipher the
information:
Example: In Domain 1 , Question 1 below, if you wish to review the resource
information (A-201 7/ch21 /p21 .23), you would review:
A – the task being addressed
201 7 – the handbook in which the information is located
Ch21 – the chapter in the handbook in which the information is located
P21 .23 – the pages in the chapter of the handbook in which the
information is located
NOTE: There are certain answers that are not located in a handbook but are
the result of job knowledge or industry practice.
Domain 1 : System Design
1 . (A-201 7/ch21 /p21 .23) A
1 5. (H-201 6/ch40/p40.1 ) C
2. (A-201 7/ch21 /p21 .23) B
1 6. (I-201 9/ch58/p58.1 ) A
3. (B-201 9/ch48/p48.20) C
1 7. (J-201 6/ch3/p3.7) B
4. (B-201 9/ch48/p48.4) C
1 8. (K-201 6/ch1 3/p1 3.23) B
5. (C-201 7/ch7/p7.1 9) C
1 9. (L-201 6/ch20/p20.6) C
6. (C-201 9/ch43/p43.3) B
20. (M-201 7/ch1 9/p1 9.3) B
7. (D-201 7/ch21 /p21 .1 5) A
21 . (M-201 7/Ch1 9/p1 9.1 ) B
8. (D-201 7/ch21 /p21 .1 6) C
22. (N-201 9/ch63/p63.2) A
9. (D-201 7/ch22/p22.1 ) A
23. (O-201 9/ch40/p40.7) A
1 0. (E-201 6/ch1 8/p1 8.1 ) B
24. (P-job knowledge) B
1 1 . (E-201 6/ch51 /p51 .2) A
25. (Q-201 6/ch4/p4.4) A
1 2. (F-201 6/Ch1 3/p1 3.1 2) B
26. (R-201 9/ch40/p40.3) B
1 3. (G-201 7/ch22/p22.8) A
27. (S-201 9/ch39/p39.1 7) C
1 4. (G-201 7/ch21 /p21 .20) B
28. (S-201 9/ch39/p39.1 7) C
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29. (T-201 6/ch44/p44.1 2) A
35. (X-201 6/ch32/p32.7) A
30. (U-201 7/ch21 /p21 .23) B
36. (Y-201 7/ch29/p29.9) A
31 . (U-201 7/ch22/p22.1 0) A
37. (Z1 -201 6/ch21 /p21 .9) A
32. (W-201 6/ch5/p5.8) A
38. (Z2-201 6/ch23/p23.5) C
33. (V-201 6/ch1 3/p1 3.4) B
39. (Z3-201 7/ch22/p22.2) C
34. (W-201 6/ch2/p2.8) C
40. (Z4-201 6/ch44/p44.3) A
Domain 2: Design Calculations
1 . (A-201 7/ch21 /p21 .1 8) B
1 6. (F-201 7/ch1 8/p1 8.1 6) C
2. (A-201 6/ch1 3/1 3.3) A
1 7. (F-201 7/ch1 4/p1 4.6) C
3. (E-201 6/ch44/p44.7) B
1 8. (G-201 7/ch1 8/p1 8.30) C
4. (A-201 7/ch36/p36.1 ) B
1 9. (G-201 7/ch1 8/p1 8.35) B
5. (B/job knowledge) B
20. (G-201 7/ch1 4/p1 4.1 2) B
6. (C-201 7/ch21 /p21 .1 9) C
21 . (H-201 6/ch21 /p21 .6) B
7. (C-201 7/ch21 /p21 .2) B
22. (H-201 7/ch21 /p21 .5) C
8. (C-201 7/ch22/p22.5) C
23. (I-201 7/ch9/p9.3) A
9. (D-201 7/ch3/p3.1 1 ) A
24. (I-201 7-ch9/p9.7) A
1 0. (D-201 7/ch9/p9.1 8) C
25. (I-201 7/ch1 6/p1 6.4) B
1 1 . (D-201 7/ch1 8/p1 8.2) B
26. (J-201 7/ch3/p3.5) A
1 2. (E-201 7/ch21 /p21 .1 6) A
27. (J-201 7/ch22/p22.8) C
1 3. (E-201 7/ch22/p22.5) A
28. (J-201 7/ch31 /p31 .1 2) B
1 4. (E-201 7/ch22/p22.1 0) B
1 5. (F-201 7/ch1 7/p1 7.1 1 ) B
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Domain 3: Procedural
1.
(A-201 9/ch44/p44. 1 3) B
7.
(G/I ndu stry practi ce) A
2.
(B-201 9/ch 41 /p44. 9-1 1 ) B
8.
(H /I n du stry practi ce) A
3.
(C-201 9/ch44/p44. 7) C
9.
(I /J ob kn owl edg e) C
4.
(D-job knowl edg e) A
1 0. (J /I n du stry practi ce) B
5.
(E-ASH RAE
1 1 . (K/I n du stry practi ce/j ob
61 . 1 /p1 6/calcu l ated) C
6.
kn owledg e) B
(F/I n du stry practi ce) C
Domain 4: Coordination
1.
(A-201 9/ch44/p44. 6) A
1 2. (L-201 9/ch60/p60. 9) A
2.
(B-201 9/ch44/p44. 7) B
1 3. (M-201 9/ch56/p56. 1 7) B
3.
(C/job knowl edg e) C
1 4. (N -201 9/ch44/p44. 8) C
4.
(D-201 9/ch44/p44. 7) A
1 5. (O-201 9/ch60/p60. 1 ) B
5.
(E-201 6/ch46/p46. 1 2) B
1 6. (P/J ob knowledg e) B
6.
(F/j ob kn owledg e) A
1 7. (Q-201 9/ch60/p60. 8) A
7.
(G /J ob kn owl edg e) C
1 8. (R-201 7/ch1 9/p1 9. 1 3) C
8.
(H -201 6/ch50/p50. 2) A
1 9. (S/J ob knowledg e) B
9.
(I /J ob kn owledg e) C
20. (T/J ob kn owl edg e) B
1 0. (J /J ob kn owl edg e) C
21 . (U /J ob knowledg e) B
1 1 . (K-201 9/ch44/p44. 8) B
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APPENDIX
Common HVAC Design Formulas
REMEMBER: Words in blue/bold are defined in the glossary (and as
popups).
1 ) Cooling & Heating Equations
For SI:
•
•
•
•
Sensible Heat
H S = cp ρ q ∆T
Latent Heat
H L = c1 ρ q ∆W
Total Heat
H T = ρ q ∆h
Sensible Heat Ratio
SHR = H S / H T
Where:
HS = Sensible Heat (kW)
HL = Latent Heat (kW)
HT = Total Heat (kW)
∆T = Temperature Difference (°K)
q = Air Volume Flow (m3/s) 3
ρ = Density of Air (1.202 kg/m )
cp = Specific Heat of Air (1.0 kJ/kg.K)
c1 = Air Latent Factor (a typical value 3010)
∆W = Humidity Ratio Difference (kg water/kg dry air)
∆h = Enthalpy Difference (kJ/kg)
SHR = Sensible Heat Ratio
For I-P:
•
•
Sensible Heat
H S = 1 .085 × CFM × ∆T
Latent Heat
H L = 0.68 × CFM × ∆WGR
= 4840 × CFM × ∆WLB
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•
Total Heat
H T = 4.5 × CFM × ∆h
•
Sensible Heat Ratio
SHR = H S / H T
Where:
HS = Sensible Heat (Btu/hr)
HL = Latent Heat (Btu/hr)
HT = Total Heat (Btu/hr)
∆T = Temperature Difference (°F)
∆WGR. = Humidity Ratio Difference (Gr.H2O/Lb.DA)
∆WLB. = Humidity Ratio Difference (Lb.H2O/Lb.DA)
∆h = Enthalpy Difference (Btu/Lb.DA)
CFM = Air Flow Rate (Cubic Feet per Minute)
SHR = Sensible Heat Ratio
2) Thermal Resistance R-Values/U-Values
A. Thermal Value (R-Value)
R=t/k
B. Thermal Transmittance (U-Value)
U = 1 / ΣR
Where:
For SI:
k = Thermal Conductivity (W/(m·K))
R = Thermal Resistance ((m²·K)/W)
U = Thermal Transmittance (W/(m²·K))
t = Thickness (m)
ΣR = Sum of the Individual R-Values
For I-P:
k = Thermal Conductivity (Btu./hr. ft. °F.)
R = Thermal Resistance (hr. ft². °F./Btu.)
U = Thermal Transmittance (Btu./hr. ft². °F.)
t = Thickness (ft)
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3) Water System Equations
For SI:
H = ρ ∙ q ∙ cp ∙ ∆T
H
q (Evap) =
(ρ ∙ cp ∙ ∆T)
Where:
H = Total Heat (kW) 3
q = Water Flow Rate (m /s) 3
ρ = Density of Water (997 kg/m )
cp = Specific Heat of Water (4.187 kJ/kg.K)
∆T = Temperature Difference (°K)
For I-P:
H=
(GPM ∙ ∆T)
24
GPM (Evap) =
(H ∙ 24)
∆T
GPM (Cond) =
(H ∙ 30)
∆T
Where:
H = Total Heat (Tons of Refrigerant)
∆T = Temperature Difference (°F)
GPM = Water Flow Rate (Gallons per Minute)
퐺푄푀 (퐸푣푎푞) . = Evaporator Water Flow Rate (Gallons per Minute)
퐺푄푀 (퐶푝표푑) . = Condenser Water Flow Rate (Gallons per Minute)
4) Air Change Rate Equations
For SI:
ACH =
(q ∙ 3600)
V
Where:
ACH. = Air Change Rate3 per Hour
q = Air Volume Flow (m3 /s)
V = Space Volume (m )
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For I-P:
ACH =
(CFM ∙ 60)
V
Where:
ACH. = Air Change Rate per Hour
CFM = Air Volume Flow
(cubic feet per minute)
V = Space Volume (ft3)
5) Mixed Air Temperature
Q
Q
TMA = (TRA ∙ ( RA ) ) + TO A ∙ ( O A )
QS A
QSA
Where:
For SI:
QSA= Supply Air (L/s)
QRA = Return Air (L/s)
QOA = Outside Air (L/s)
TMA = Mixed Air Temperature (°C)
TRA = Return Air Temperature (°C)
TOA = Outside Air Temperature (°C)
For I-P:
QSA= Supply Air (CFM)
QRA = Return Air (CFM)
QOA = Outside Air (CFM)
TMA = Mixed Air Temperature (°F)
TRA = Return Air Temperature (°F)
TOA = Outside Air Temperature (°F)
6) Ductwork Equations
•
Total Pressure
pt = ps + pv
Where:
p t = Total Pressure (Pa)
p s = Static Pressure (Pa)
p v = Velocity Pressure (Pa)
•
Velocity
V=
Q
A
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Where:
For SI:
V = Fluid Mean Velocity (m/s)3
Q = Volumetric Flow Rate (m /s)
A = Cross-Sectional Area of Duct (m²)
For I-P:
V = Fluid Mean Velocity (FPM)
Q = Volumetric Flow Rate (CFM)
A = Cross-Sectional Area of Duct (ft²)
7) Fan Affinity Laws
A. Flow Rate
B. Static Pressure
N
Q1 = Q 2 ∙ ( 1 )
N2
P1 = P2 ∙ (
C. Electrical Power
Where:
N1 2
)
N2
W1 = W2 ∙ (
N1 3
)
N2
For SI:
Q = Volumetric Flow Rate (m³/s)
N = Rotational Speed, Revolutions Per Minute (RPM)
P = Static Pressure (Pa)
W = Electrical Power (W)
For I-P:
Q = Volumetric Flow Rate (CFM)
N = Rotational Speed, Revolutions Per Minute (RPM)
P = Static Pressure (in.wg)
W = Electrical Power (W)
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8) Pump Affinity Laws (At Constant Pump Impeller Diameter)
•
Flow Rate
•
Pump Head
N
Q1 = Q 2 ∙ ( 1 )
N2
P1 = P2 ∙ (
•
Electrical Power
Where:
N1 2
)
N2
W1 = W2 ∙ (
N1 3
)
N2
For SI:
Q = Volumetric Flow Rate (m³/s)
N = Rotational Speed, Revolutions Per Minute (RPM)
P = Pump Head (bar)
W = Electrical Power (W)
For I-P:
Q = Volumetric Flow Rate (GPM)
N = Rotational Speed, Revolutions Per Minute (RPM)
P = Static Pressure (ft.wg)
W = Electrical Power (W)
9) Pump Net Positive Suction Head (NPSH) Calculations
•
•
NPSH AVAIL > NPSH REQ’D
Net Positive Suction Head Available:
NPSH AVAIL = H A ± H S − H F − H VP
Where:
For SI:
NPSHAVAIL = Net Positive Suction Available at Pump (m)
NPSHREQ’D = Net Positive Suction Required at Pump (m)
HA = Pressure at Liquid Surface (m—10.2 m for Water at Atmospheric Pressure)
HS = Height of Liquid Surface Above (+) or Below (−) Pump (m)
HF = Friction Loss between Pump and Source (m)
HVP = Absolute Pressure of Water Vapor at Liquid Temperature (m)
For I-P:
NPSHAVAIL = Net Positive Suction Available at Pump (ft)
NPSHREQ’D = Net Positive Suction Required at Pump (ft)
HA = Pressure at Liquid Surface (ft—34 ft for Water at Atmospheric Pressure)
HS = Height of Liquid Surface Above (+) or Below (−) Pump (ft)
HF = Friction Loss between Pump and Source (ft)
HVP = Absolute Pressure of Water Vapor at Liquid Temperature (ft)
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1 0) Cooling Tower Equations
For SI:
•
Cycles of Concentration
C=
•
Blowdown
B=
•
(E + D + B)
(D + B)
E − ((C − 1 ) ∙ D)
(C − 1 )
Evaporation
E = 0.00 1 53 ∙ R ∙ m
•
Drift
D = 0.0002 ∙ m
•
Range
R = EWT − LWT
Where:
m = Circulating Cooling Water (m3/hr)
B = Blowdown (m3/hr)
C = Cycles of3 Concentration
D = Drift (m /hr) 3
E = Evaporation (m /hr)
EWT = Entering Water Temperature (°C.)
LWT = Leaving Water Temperature (°C.)
R = Range (°C.)
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For I-P:
•
Cycles of Concentration
C=
•
Blowdown
B=
•
(E + D + B)
(D + B)
E − ((C − 1 ) ∙ D)
(C − 1 )
Evaporation
E = GPM (Cond) ∙ R ∙ 0.00085
•
Drift
D = 0.0002 ∙ GPM (Cond)
•
Range
R = EWT − LWT
Where:
B = Blowdown (GPM)
C = Cycles of Concentration
D = Drift (GPM)
E = Evaporation (GPM)
EWT = Entering Water Temperature (°F.)
LWT = Leaving Water Temperature (°F.)
R = Range (°F.)
1 1 ) Efficiencies
For SI:
•
Coefficient of Performance (COP)
COP =
•
To tal Cooling Capaci ty (W)
Compre ss or Inpu t Power (W) + Conden s er Fan Inpu t Power (W)
Energy Efficiency Ratio (EER)
EE R =
Ne t Cooling Capaci ty (W) ∙ 3.4 1 3
To tal Inpu t Power (W)
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For I-P:
•
Coefficient of Performance (COP)
COP =
•
To tal Cooling Capaci ty (BTU/h)
(Compre ss or (W) + Conden s er Fan (W)) ∙ 3.4 1 3
Energy Efficiency Ratio (EER)
EE R =
Ne t Cooling Capaci ty (BTU/h)
To tal Inpu t Power (W)
1 2) Cooling Towers and Heat Exchangers
•
•
•
APPROACH (COOLING TOWER) = LWT – AWB
APPROACH (HEAT EXCHANGER) = EWTHS – LWTCS
RANGE = EWT – LWT
Where:
For SI:
EWT = Entering Water Temperature (°C)
LWT = Leaving Water Temperature (°C)
AWB = Ambient Wet Bulb Temperature (°C)
HS = Hot Side
CS = Cold Side
For I-P:
EWT = Entering Water Temperature (°F)
LWT = Leaving Water Temperature (°F)
AWB = Ambient Wet Bulb Temperature (°F)
HS = Hot Side
CS = Cold Side
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GLOSSARY
ASHRAE Terminology is a comprehensive online glossary of more than 3700
terms and definitions related to the built environment, with a focus on
HVAC&R, as well as building envelope, electrical, lighting, water and energy
use, and measurement terms.
Below are some key terms related to the HVAC designer job.
Term
Acceptable
indoor air
quality
Air changes
Airconditioning
Air
economizer
Approach
Aspect ratio
Basis of
design (BOD)
Blowdown
Definition
air in which there are no known contaminants at harmful
concentrations as determined by cognizant authorities and with
which a substantial majority (80% or more) of the people
exposed do not express dissatisfaction
expression of the amount of air movement or air leakage into or
out of a building in terms of the number of building volumes or
room volumes exchanged
the process of treating air to meet the requirements of a
conditioned space by controlling its temperature, humidity,
cleanliness, and distribution
a duct and damper arrangement and automatic control system
that together allow a cooling system to supply outdoor air to
reduce or eliminate the need for mechanical cooling during mild
or cold weather
(1 ) in a water cooling tower or evaporative cooling device, the
difference between the average temperature of the circulating
water leaving the device and the average wet-bulb temperature
of the entering air. (2) in heat exchangers, the temperature
difference between the leaving fluids
(1 ) in any rectangular configuration, the ratio of the longer
dimension to the shorter. (2) ratio of the length to width of a
rectangular air duct
a document that records the concepts, calculations, decisions,
and product selections used to meet the o wner’s project
requirements and to satisfy applicable regulatory requirements,
standards, and guidelines; the document includes both narrative
descriptions and lists of individual items that support the design
process
(1 ) discharge of water from a steam boiler or open recirculating
system that contains high total dissolved solids; the addition of
makeup water will reduce the concentration of dissolved solids to
minimize their precipitation. (2) in pressure relief-devices, the
difference between actuation pressure of a pressure relief valve
and reseating pressure, expressed as a percentage of set
pressure or in pressure units
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Breathing
zone
the region within an occupied space between planes 3 and 72 in.
(75 and 1 800 mm) above the floor and more than 2 ft (600 mm)
from the walls or fixed air-conditioning equipment
Bypass factor
the percentage of the air that does not come into contact with the
coil; the remaining air is assumed to exit the coil at the average
coil temperature. See also apparatus dew point
Capacity
(1 ) measure of the maximum amount of energy or material that
may be stored in a given system; See also nameplate rating; airconditioning capacity. (2) the rate of heat removal by the
refrigerant used in the compressor or condensing unit in a
refrigerating system. This rate equals the product of the
refrigerant mass flow rate and the difference in the specific
enthalpies of the refrigerant vapor at its thermodynamic state
entering the compressor or condensing unit and refrigerant liquid
at the thermodynamic state entering the mass flow control
device. (3) the rate that heat is removed or added to a system.
(4) maximum load for which a machine, apparatus, device, or
system is designed or constructed
Cavitation
(1 ) formation by mechanical forces of vapor in liquids;
specifically, the formation of vapor cavities in the interior or on
the solid boundaries of liquids in motion, where the pressure is
reduced to a critical value without a change in ambient
temperature. (2) formation of cavities on a surface of a solid by
liquid moving over it with velocity high enough to induce erosion
of the surface when the cavity collapses. (3) in pumps, cavitation
occurs when the pressure of the fluid is below the vapor pressure
of the fluid at that temperature; cavitation has been described as
having marbles or small stones inside the impeller casing.
Cavitation over an extended period of time will erode the impeller
and cause pump failure
Chill factor
the apparent temperature felt on exposed skin as a function of air
temperature and wind speed. Chill factor is expressed in time
(e.g., 1 1 seconds) to express how long it will take exposed skin
to freeze. Compare to wind chill, which is expressed as a
temperature
Coefficient of
performance
(COP)
(1 ) ratio of the rate of net heat output to the total energy input
expressed in consistent units and under designated rating
conditions. (2) ratio of the refrigerating capacity to the work
absorbed by the compressor per unit time
Coefficient of
performance
(COP) – heat
pump
the ratio of the rate of heat delivered to the rate of energy input,
in consistent units, for a complete heat pump system, including
the compressor and, if applicable, auxiliary heat, under
designated operating conditions
Compression
tank
pneumatic cushioning device, operating at system pressure, that
absorbs fluid expansion as a result of temperature change and
prevents unnecessary periodic operation of the relief valve.
Compare to expansion tank
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Cooling
design
temperature
Cooling
design wetbulb
temperature
Cooling
system
energy
coefficient of
performance
Daily range
Degree day
(Kelvin-day)
Dew-point
temperature
Direct digital
control (DDC)
Directexpansion
(DX)
refrigeration
systems
Displacement
ventilation
system
the outdoor dry-bulb temperature equal to the temperature that is
exceeded by 1 % of the number of hours during a typical weather
year
the outdoor wet-bulb temperature equal to the temperature that
exceeds a stated number of hours during a typical weather year.
The value is normally stated as a percent. This value is
applicable to cooling systems where the main purpose is
dehumidification and the prevention of mold and mildew
a ratio calculated by dividing the net total cooling capacity in
watts by the total power input in watts (excluding reheaters and
humidifiers) at any given set of rating conditions. The net total
cooling capacity is the total gross capacity minus the energy
dissipated into the cooled space by the blower system
difference between high and low temperatures for a typical day.
Used in HVAC load calculations
the difference in temperature between the outdoor mean
temperature over a 24-hour period and a given base
temperature, used in estimating heating and cooling energy use.
For any one day, there are as many degree days (Kelvin-days)
as there are degrees Fahrenheit (degrees Celsius) departure of
the mean temperature for the day from the base temperature
temperature of moist air saturated at pressure p, with the same
humidity ratio W as that of the given sample of moist air. It is
defined as the solution td(p, W) of the equation: Ws(p, td) = W
a type of control where controlled and monitored analog or binary
data (e.g., temperature, contact closures) are converted to digital
format for manipulation and calculations by a digital computer or
microprocessor, then converted back to analog or binary form to
control physical devices
(1 ) system in which the cooling effect is obtained directly from the
expansion of the liquid refrigerant into a vapor. (2) common term
applied to an air-conditioning or refrigeration system that utilizes
the vapor-compression refrigeration cycle. In a vaporcompression refrigeration cycle, the refrigerant removes heat in
the evaporator by directly expanding the entering liquid
refrigerant into vapor as it leaves the evaporator. The vapor is
then compressed and piped to a condenser where the heat
removed by the evaporator and the heat of compression are
rejected to another medium so that the gaseous refrigerant is
condensed to a liquid. The liquid is then piped to a pressure
reducing device/metering device to be supplied to the evaporator
a type of air-distribution system, used only for cooling purposes,
in which air at a temperature below room temperature is supplied
to the floor level at a low discharge velocity [<1 00 fpm (0.5m/s)]
and is returned near ceiling level. Thermal plumes, which
develop over heat sources in the room, drive the overall floor-toceiling air motion, producing a stratified environment with cooler
and fresher air near the floor and warmer and less fresh air near
the ceiling
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Distribution
system
District
cooling
Diversity
factor
Draft
(1 ) conveying means, such as ducts, pipes, and wires, to bring
substances or energy from a source to the point of use. The
distribution system includes auxiliary equipment such as fans,
pumps, and transformers. (2) parts of a cooling tower, beginning
with the inlet connection, that distribute the hot, circulating water
within the tower to the points where it contacts the air
concept of providing and distributing, from a central plant, cooling
energy to a surrounding area (district) of tenants or clients
(residences, commercial businesses, or institutional sites).
Compare to district heating
ratio, or percentage, obtained when the total output capacity of a
system is divided by the total output capacity of all the terminal
devices connected to the systems. Example: to express the ratio
of VAV supply air fan capacity to the total capacity of the VAV
terminal devices as a percentage
(1 ) current of air, when referring to pressure difference that
causes a current of air or gases to flow through a flue, chimney,
heater, or space. (2) current of air, when referring to localized
effect (generally, the unwanted local cooling of the body caused
by air movement) caused by one or more factors of high air
velocity, low ambient temperature, or direction of airflow whereby
more heat is withdrawn from a person’s skin than is normally
dissipated
difference between the static water level and the active-pumping
Drawdown
water level
Dry-bulb
(1 ) temperature of air indicated by an ordinary thermometer
temperature
shielded from solar and long wave radiation. (2) in general, any
(DBT)
thermometer that indicates the temperature of air (or other
fluids); distinguished from a wet-bulb thermometer
Energy
(1 ) ratio of net cooling capacity in Btu/h to total rate of electric
efficiency ratio input in watts under designated operating conditions. (2) ratio of
(EER)
the net total cooling capacity to the effective power input at any
given set of rating conditions, in watts per watt
Energy
(1 ) system that has to be operated during on-peak as well as offstorage
peak periods. (2) system wherein the load demand is met by a
system
combination of stored thermal energy and an energy conversion
device
Enthalpy
(also known as heat content), thermodynamic quantity equal to
the sum of the internal energy of a system plus the product of the
pressure volume work done on the system. H = E + pv,
where H = enthalpy or total heat content, E = internal energy of
the system, p = pressure, and v = volume. (Compare to specific
enthalpy)
the steady-state condition during which the fluctuations of
Equilibrium
variables being measured remain within stated limits
mixture of substances whose solid and liquid phases in
Eutectic
equilibrium have identical composition. Such a mixture has a
minimum freezing point
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Exfiltration
(1 ) leakage of indoor air out of a building through similar types of
openings. Like natural ventilation, it is driven by natural and/or
artificial pressure differences. (2) uncontrolled outward air
leakage from conditioned spaces through unintentional openings
in ceilings, floors, and walls to unconditioned spaces or the
outdoors caused by pressure differences across these openings
due to wind, inside-outside temperature differences (stack
effect), and imbalances between supply and exhaust airflow
rates
Exhaust air
air that must be removed from a space due to contaminants,
regardless of pressurization
Expansion
tank
partially filled tank for the accommodation of volume expansion
of a fluid, typically water. Compare to compression tank
Face velocity
the rate of air movement at the face of the device (airflow rate
divided by face area), expressed in m/s (fpm) to three significant
figures
Failsafe
1 ) position or mode of operation a controlled device takes on
removal of the control signal and/or power. (2) to return to a
position that, on loss of control system power, allows the
controlled system to go to a safe mode
the ratio of fan power output to fan power input
Fan total
efficiency
Fenestration
(1 ) commonly used to refer to any opening, usually glazed, in a
building envelope; windows. Examples include windows, plastic
panels, clerestories, skylights, glass doors that are more than
one-half glass, and glass block walls. (2) in an external wall of a
building, any area that allows light to pass
Free area
(1 ) actual open area between the fins of a grille or register. (2)
total area through which air can pass in a grille, face, or register
Friction loss
pressure loss due to friction between a flowing fluid and its
contact surface
Global
warming
potential
(GWP)
an index developed to provide a simplified means of describing
the relative ability of a chemical compound to affect radiative
forcing, if emitted to the atmosphere, over its lifetime in the
atmosphere, and thereby to affect the global climate. Radiative
forcing reflects the factors that affect the balance between the
energy absorbed by the earth and the energy emitted by it in the
form of longwave infrared radiation. The GWP is defined on a
mass basis relative to carbon dioxide. The GWP for a compound
must be calculated up to a particular integrated time horizon, for
example, 20, 1 00, or 500 years. The time horizon most widely
accepted is 1 00 years
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Gross floor
area
Heat capacity
Heat gain
(heat uptake)
Heat index
Heat loss
Heat pump
Humidifying
effect
Hydraulic
diameter
HVAC zone
Indoor air
the sum of the floor areas of all the spaces within the building
with no deductions for floor penetrations other than atria. Gross
floor area is measured from the exterior faces of exterior walls or
from the centerline of walls separating buildings, but it excludes
covered walkways, open roofed-over areas, porches and similar
spaces, pipe trenches, exterior terraces or steps, roof overhangs,
parking garages, surface parking, and similar features
1 ) the amount of heat necessary to raise the temperature of a
given mass one degree; numerically, the mass multiplied by the
specific heat. (2) the capacity of a body to store heat
quantity of heat absorbed by an enclosed space or system
an index that combines air temperature and relative humidity in
an attempt to determine the human-perceived equivalent
temperature (how hot it feels, also termed
the felt air temperature). When the relative humidity is high, the
evaporation rate is reduced, so heat is removed from the body at
a lower rate, causing it to retain more heat than it would in dry
air. Compare wind chill
(1 ) (also known as infiltration losses) energy required to warm
outdoor air leaking in through cracks and crevices around doors
and windows, through open doors and windows, and through
porous building materials. (2) (also known
as transmission losses) heat transferred through confining walls,
glass, ceilings, floors, or other surfaces. (3) See also heat gain
(heat uptake)
thermodynamic heating/refrigerating system to transfer heat. The
condenser and evaporator may change roles to transfer heat in
either direction. By receiving the flow of air or other fluid, a heat
pump is used to cool or heat. Heat pumps may be the air source
with heat transfer between the indoor air stream to outdoor air or
water source with heat transfer between the indoor air stream
and a hydronic source (ground loop, evaporative cooler, cooling
tower, or domestic water)
product of the mass of water evaporated times the latent heat at
the evaporating temperature
(1 ) for a fully filled duct or pipe whose cross section is a regular
polygon, the hydraulic diameter is equivalent to the diameter of a
circle inscribed within the wetted perimeter. For a fully filled duct
or pipe whose cross section is round, the hydraulic diameter is
equivalent to the diameter of the duct of pipe. (2) a commonly
used approximation is to take four times the flow area divided by
the perimeter of the solid boundary in contact with the fluid
a space or group of spaces within a building with heating and
cooling requirements that are sufficiently similar so that desired
conditions (e.g., temperature) can be maintained throughout
using a single sensor (e.g., thermostat or temperature sensor)
air inside the building envelope
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I n d o o r ai r
attri bu te s o f th e res pi rabl e ai r i n s i d e a bu i l d i n g ( i n d o o r cl i m ate) ,
q u al i ty ( I AQ)
i n cl u d i n g g as e o u s co m po s i ti o n , h u m i d i ty, te m pe ratu re , an d
co n tam i n an ts . S e e al s o i n d o o r e n vi ro n m e n t q u al i ty ( I E Q) . S e e
al s o s i ck bu i l d i n g syn d ro m e
I n d oor
a pe rce i ve d i n d o o r e xp e ri e n ce o f th e bu i l d i n g i n d o o r en vi ro n m e n t
e n vi ro n m e n t
th at i n cl u d e s as pe cts o f d es i g n , an al ys i s , an d o pe rati o n o f
q u al i ty ( I E Q)
e n e rg y e ffi ci e n t, h e al th y, an d co m fo rtabl e b u i l d i n g s . Fi e l d s o f
speci al i z ati o n i n cl u d e arch i te ctu re , H VAC d es i g n , th erm al
co m fo rt, i n d o o r ai r q u al i ty (I AQ) , l i g h ti n g , aco u s ti cs , an d co n tro l
s ys te m s . S e e i n d o o r ai r q u al i ty ( I AQ)
I n fi l trati o n
u n co n tro l l e d i n ward ai r l e akag e to co n d i ti o n e d space s th ro u g h
u n i n te n ti o n al o pe n i n g s i n ce i l i n g s , fl o o rs , an d wal l s fro m
u n co n d i ti o n e d spaces o r th e o u td o o rs , cau s e d by th e s am e
pre s s u re d i ffe re n ce s th at i n d u ce e xfi l trati o n
I n h i bi to r
ch e m i cal s u bs tan ce th at re d u ce s th e rate o f co rro s i o n , s cal e
fo rm ati o n , fo u l i n g , o r s l i m e pro d u cti on
J acke t
( 1 ) i n teg ral co ve ri n g , s o m e ti m e s fabri c rei n fo rce d , th at i s appl i e d
o ver i n s u l ati o n . Al s o , th e co re , s h i e l d , o r arm o r o f a cabl e to
pro vi d e m e ch an i cal o r e n vi ro n m e n tal pro te cti o n . ( 2 ) se al e d
s p ace aro u n d a pi e ce o f e q u i p m e n t or a s to rag e u n i t, th ro u g h
wh i ch a th e rm al m e d i u m can be ci rcu l ate d
J et
co n ce n trate d ai rs tre am fo rm e d as pri m ary ai r l e ave s th e d i ffu s er
K- facto r
ti m e rate o f s te ad y- s tate h eat fl o w th ro u g h a u n i t are a o f a
( th e rm al
h o m o g e n e o u s m ate ri al , i n d u ce d by a u n i t te m pe ratu re g rad i en t i n
co n d u cti vi ty)
a d i recti o n pe rpe n d i cu l ar to th at u n i t are a. U n i ts are Btu
2
i n . /h · ft · ° F o r B tu /h · ft· ° F [W/( m · K) ]
Late n t h e at
th e ch an g e i n e n th al py as so ci ated wi th a ch an g e i n h u m i d i ty
rati o , cau s e d by th e ad d i ti o n o r re m o val o f m o i s tu re
Late n t h e at o f
q u an ti ty o f h e at re q u i re d to ch an g e a u n i t m as s o f i ce to wate r at
fu s i o n
3 2 ° F ( 0 ° C ) tem pe ratu re , m e as u red i n B tu /l bm ( J /kg )
Li fe - cycl e co s t
co s t o f e q u i pm e n t o ver i ts e n ti re l i fe i n cl u d i n g ope rati n g ,
m ai n te n an ce , an d re pai r/repl ace m e n t co s t. M ay al s o i n cl u d e
d e co m m i s s i o n i n g co s t
Li ft
ve rti cal d i s tan ce th at fl u i d m u s t be pu m pe d to re ach a s pe ci fi e d
h ei g h t
Lo ad pro fi l e
s u m m ary o f th e rm al o r o th e r e n e rg y l o ad s i n a system o ver a
pe ri o d o f ti m e . N o te : fo r e xam pl e , a co m m o n l o ad pro fi l e o n a
pe ak d es i g n d ay fo r th e rm al s to rag e d es i g n s wo u l d s h o w h o u rl y
s ys te m l o ad re q u i re m en ts fo r 2 4 h o u rs
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Makeup air
(dedicated
replacement
air)
(1 ) dedicated replacement air. (2) air brought into a building from
the outdoors to replace air that is exhausted. Makeup air may or
may not be conditioned. (3) any combination of outdoor and
transfer air intended to replace exhaust air and exfiltration. (4) in
a clean room, air introduced to the secondary air system for
ventilation, pressurization, and replacement of exhaust air. (5) in
a laboratory or kitchen, outdoor air deliberately brought into the
building from the outside and supplied to the vicinity of an
exhaust hood to replace air, vapor, and contaminants being
exhausted. Makeup air is generally filtered and fan forced, and it
may be heated or cooled depending on the requirements of the
application. Makeup air may be delivered through outlets integral
to the exhaust hood or through outlets in the same room
Mean radiant theoretical uniform surface temperature of an enclosure in which
temperature an occupant would exchange the same amount of radiant heat
as in the actual nonuniform enclosure. Compare to operative
temperature
Mean
can be calculated as the average of temperature readings over a
temperature period of time or the average of the high and low temperatures
over a given time
Mechanical
reducing the temperature of a fluid by using vapor compression,
cooling
absorption, desiccant dehumidification combined with
evaporative cooling, or other energy-driven thermodynamic
means. Indirect or direct evaporative cooling alone is not
considered mechanical
Mechanical
raising the temperature or change of phase of a solid or fluid by
heating
use of fossil-fuel burners, electric resistance heaters, heat
pumps, or other systems that require energy to operate
Mechanical
(1 ) the active process of supplying or removing air to or from an
ventilation
indoor space by powered equipment such as motor-driven fans
and blowers but not by devices such as wind-driven turbine
ventilators and mechanically operated windows. (2) ventilation
provided by mechanically powered equipment, such as motordriven fans and blowers, but not by devices such as wind-driven
turbine ventilators and mechanically operated windows
Metabolic rate 1 ) rate of energy production of the body. The rate varies with the
type of activity. (2) the rate of transformation of chemical energy
into heat and mechanical work by metabolic activities within an
organism, usually expressed in terms of unit area of the total
body surface. Metabolic rate is expressed in met units
Minimum
scaled rating of the effectiveness of air filters. The scale is
efficiency
designed to represent the worst-case performance of a filter
reporting
when dealing with particles in the range of 0.3 to 1 0 micrometers.
values
The MERV rating is from 1 to 1 6. Higher MERV ratings
(MERV)
correspond to a greater percentage of particles captured on each
pass, with a MERV rating of 1 6 filter capturing more than 95% of
particles over the full range
Miscibility
ability of a liquid or gas to dissolve uniformly in another liquid or
gas
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Moisture
carryover
Natural
ventilation
Net positive
suction head
(NPSH)
Nominal
capacity
Nonstandard
part-load
value (NPLV)
Net
occupiable
area
Occupiable
space
Occupied
zone
Operating
differential
Operative
temperature
retention and transport of water droplets in a gas stream (usually
air) (e.g., water droplets formed by bridging fins of a coil and
transported by the airstream)
movement of air into and out of a space primarily through
intentionally provided openings (such as windows and doors),
through nonpowered ventilators, or by infiltration
minimum head at the pump inlet to prevent the liquid being
pumped from flashing into a vapor at that temperature and
pressure and potentially causing the pump to cavitate. There are
two types of NPSH values: net positive suction head available
(NPSHA) and net positive suction head required (NPSHR).
NPSHA is actual or available head at the pump impeller and
should be greater than the vapor pressure of operating fluid at
the operating temperature. NPSHR is the value stated by the
pump manufacturer that is the minimum required head at the
pump impeller. NPSHA should be greater than NPSHR. Values
of NPSH are expressed as head in units of feet (kPa)
(1 ) the capacity recorded and reported by a given test. (2) the
capacity reported by the manufacturer for a specified device
a single-number part-load efficiency figure of merit calculated
and referenced to conditions other than IPLV conditions for units
that are not designed to operate at ARI standard rating
conditions
the floor area of an occupiable space defined by the inside
surfaces of its walls but excluding shafts, column enclosures, and
other permanently enclosed, inaccessible, and unoccupiable
areas. Obstructions in the space such as furnishings, display or
storage racks, and other obstructions, whether temporary or
permanent, are considered to be part of the net occupiable area
(1 ) any enclosed space inside the pressure boundary (including,
but not limited to, all habitable spaces, toilets, closets, halls,
storage and utility areas, and laundry areas) and intended for
human activities. (2) that portion of the premises accessible to or
occupied by people, excluding machinery rooms
the portion of the space that is normally occupied. The occupied
zone is typically defined as encompassing all space from the
floor level, excluding the space from the floor to 0.25 ft (0.076 m)
above the floor, to 6 ft (1 .83 m) above the floor and excluding the
space from the wall to 2 ft (0.61 m) away from any wall
difference between the cut-out and cut-in at the sensing element
the uniform temperature of an enclosure in which an occupant
would exchange the same amount of heat by radiation plus
convection as in the actual nonuniform environment. Compare to
mean radiant temperature
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Optimization
(1 ) collection of data in a control system in order to produce the
best possible output, usually in accordance with what is most
economical. (2) procedure used in the design of a system to
maximize or minimize some performance index. May entail the
selection of a component, a principle of operation, or a
technique. (3) refinement of a system to reduce its energy
requirements
Outdoor air
1 ) air outside a building or taken from the external atmosphere
and, therefore, not previously circulated through the system. (2)
ambient air that enters a building through a mechanical
ventilation system, through intentional openings for natural
ventilation, or by infiltration. (3) compare to outside air
Outlet velocity average velocity of fluid emerging from an outlet measured in the
plane of the outlet
Outside air
Air external to a defined zone (e.g., corridors)
Overall heat
heat flow per area for a given construction and for an overall
temperature difference of one degree
transfer
coefficient
Overall
quantity of heat transferred per unit of temperature difference into
thermal
a building through its walls or roof, due to solar heat gain and
transfer value outdoor/indoor temperature difference
(OTTV)
Packaged
a factory selected wall sleeve and separate unencased
terminal aircombination of heating and cooling components, assemblies, or
conditioner
sections. It may include heating capability by hot water, steam, or
(PTAC)
electricity and is intended for mounting through the wall to serve
a single room or zone
Part-load
single number figure of merit expressing part-load efficiency for
value
equipment on the basis of weighted operation at various partialload capacities for the equipment; expressed in kilowatts per ton
of refrigeration
Performance the ratio of capacity to power input at specified operating
factor
conditions. Using consistent units, the performance factor may
be expressed in dimensionless form as a coefficient of
performance (COP) or as the energy efficiency ratio (EER)
Plane radiant uniform temperature of an enclosure where the radiance on one
temperature
side of a small plane element is the same as in the nonuniform
actual environment
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Plenum
(also called plenum box and plenum chamber) (1 ) a
compartment or chamber, to which one or more ducts are
connected, that forms a part of the air-distribution system and
that is not used for occupancy or storage. A plenum often is
formed in part or in total by portions of the building. (2) an air
compartment that is attached to, or is an integral part of, a
forced-air furnace which is designed to either distribute the
heated air after it leaves the heat exchanger in the case of a
supply plenum or to collect air that enters the return inlet in the
case of a return plenum. (3) component forming an interface
between a ductwork and one or more air terminal devices; by
virtue of its design or by the inclusion of accessories, it can also
be used to equalize the pressure/velocity across the air terminal
device
Predicted
mean vote
(PMV)
index that predicts the mean value of thermal sensation votes of
a large group of persons, expressed on a seven-point scale
Predicted
percentage
dissatisfied
(PPD)
index that predicts the percentage of a large group of people who
are likely to feel thermally dissatisfied for the body as a whole
(i.e., feel either too warm or too cold)
Pressure
dependent
(PD)
the flow rate through a flow control device varies in response to
changes in system pressure
Pressure
head
hydrostatic height of fluid, equal to the fluid pressure divided by
the density times the gravitational acceleration
Pressure
independent
the flow rate through a flow control device is not affected by
changes in system pressure
Pressurelimiting device
a pressure-responsive electronic or mechanical control designed
to automatically stop the operation of the pressure-imposing
element at a predetermined pressure
Pressuresustaining
valve
valve providing maintenance of designated pressure level within
a system
Primary air
(1 ) any air that is mixed with fuel at or in a burner prior to
burning. (2) in a clean room, air that recirculates through the
work space. (3) treated supply air that enters the space through
any supply air device, such as air outlet or through any air supply
terminal, such as a VAV unit or fan terminal unit. The air is not
mixed with space air before entering the space
Pump down
of refrigerant, withdrawal of all refrigerant from the low side of a
system by pumping it to either the condenser or the liquid
receiver
Range
(1 ) difference between the highest and the lowest operational
values, such as pressure, temperature, rate of flow, or computer
values. (2) region between limits within which a quantity is
measured, transmitted, or received, expressed by stating the
lower and upper range values
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Recirculated
air
Recirculating
system
Refrigerating
effect
Return air
air taken from a space and returned to that space, usually after
being passed through a conditioning system. The part of the
return air that is reused. Air removed from a space and reused as
supply air
a domestic or service hot-water distribution system that includes
a closed-circulation circuit designed to maintain usage
temperatures in hot-water pipes near terminal devices (e.g.,
lavatory faucets, shower heads) in order to reduce the time
required to obtain hot water when the terminal device valve is
opened. The motive force for circulation is either natural (due to
water density variations with temperature) or mechanical
(recirculation pump)
in a refrigeration system, the rate of heat removal
air removed from a space to be recirculated or exhausted. Air
extracted from a space and totally or partially returned to an airconditioner, furnace, or other heating, cooling, or ventilating
system
Seasonal
for the cooling season, the ratio of the total heat removed from
energy
the conditioned space to the total electrical energy input if the
efficiency ratio combined appliance operated exclusively in a space-cooling-only
– cooling only (COOL) mode. The quantity is expressed in units of Btu/Wh
(SEER)
Sensible
a panel designed for sensible cooling of an indoor space through
cooling panel heat transfer to the thermally effective panel surfaces from the
occupants and/or indoor space by thermal radiation and natural
convection
Sensible heat the energy exchanged by a thermodynamic system that relates
to a change of temperature
Sensible heat [also known as sensible heat factor ( SHF)], the ratio of sensible
ratio (SHR)
heat transfer to total (sensible + latent) heat transfer for a
process. Also see sensible heat and latent heat
Setback
reduction of heating (by reducing the setpoint) or cooling (by
increasing the setpoint) during hours when a building is
unoccupied or during periods when lesser demand is acceptable
Setpoint
point at which the desired temperature (°F [°C]) of the heated or
cooled space is set
Shading
the ratio of solar heat gain at normal incidence through glazing to
coefficient
that occurring through standard thickness of clear, double(SC)
strength glass. Shading coefficient does not include interior,
exterior, or integral shading devices
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Sick building
building in which the indoor air quality is unacceptable to a
substantial majority of people exposed. Volatile organic
compounds (VOC) of various types and other contaminants are
present in concentrations sufficient to act synergistically on many
occupants, resulting in a sick building syndrome, usually when
concentrations are too high. This syndrome does not conform to
a particular illness and is difficult to trace to a specific source.
See indoor air quality (IAQ); volatile organic compounds (VOC
Sick building
syndrome
the term may apply to a combination of ailments (a syndrome)
associated with a place of work, residence, or assembly. Sick
building syndrome can be related to a lack of adequate outdoor
air ventilation, improper exhaust, ventilation of odors, chemicals
or fumes, or poor indoor air quality. Other sources of sick
buildings may be linked to contaminants produced by outgassing
of some types of building materials, VOC, bacteria molds, etc.
This syndrome does not conform to a particular illness and is
difficult to trace to a specific source. See indoor air quality,
volatile organic compounds (VOC)
Smokecontrol
system
an engineered system that uses mechanical fans to produce
airflows and pressure differences across barriers to limit smoke
movement
Specific
enthalpy
enthalpy per unit mass of substance
Solar heat
gain
coefficient
(SHGC)
the ratio of the solar heat gain entering the space through the
fenestration area to the incident solar radiation. Solar heat gain
includes directly transmitted solar heat and absorbed solar
radiation, which is then reradiated, conducted, or convected into
the space
Specific heat
(CP)
ratio of the quantity of heat required to raise the temperature of a
given mass of any substance one degree to the quantity required
to raise the temperature of an equal mass of a standard
substance one degree (usually water at 59°F [1 5°C]). The units
are expressed in Btu/lb·°F [J/(kg·K)]
Specification
statement of a set of requirements to be satisfied by a material,
product, system, or service that indicates the procedures for
determining whether each of the requirements is satisfied. Note:
it is desirable to express the requirements numerically in terms of
appropriate units, together with their limits
Start-up
a set of procedures to be followed in the systematic initial
sequencing or energizing of components, devices, equipment,
and systems
Static head
the pressure due to the weight of the fluid above the point of
measurement. In a closed system, static head is equal on both
sides of the pump
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Static
pressure
the actual pressure of the fluid, which is associated not with its
motion but with its state. The pressure is exerted uniformly
throughout the entire fluid. The portion of the fluid pressure which
exists by virtue of the degree of compression only. If expressed
as gage pressure, it may be negative or positive. In a dynamic
system, static pressure is the difference between total and
velocity pressures. in. H 2O (kPa)
Stratification
division into a series of layers, as with thermal gradients across a
fluid in motion or at rest
Stratified
storage
thermal storage vessel in which a thermocline exists
Stratified
system
an air-distribution system that, during the cooling operation, limits
the amount of mixing in the space and instead relies on thermal
plumes to produce a stratified environment with cooler and
fresher air near the floor and warmer and less fresh air near the
ceiling. Examples are underfloor air-distribution system (UFAD)
and DV systems
Suction lift
combination of static suction lift and friction head in suction
piping when the source of liquid is below the pump centerline
Supply air
(1 ) air delivered by mechanical or natural ventilation to a space,
composed of any combination of outdoor air, recirculated air, or
transfer air. (2) air entering a space from an air-conditioning,
heating, or ventilating apparatus for the purpose of comfort
conditioning. Supply air is generally filtered, fan forced, and
either heated, cooled, humidified, or dehumidified as necessary
to maintain specified conditions. Only the quantity of outdoor air
within the supply airflow may be used as replacement air
Temperature
gradient
temperature variation per unit distance or time along the heat
flow path
Thermal
conductance
(C-factor)
thermal conductivity is the heat flux through a flat body induced
by a unit temperature difference between the surfaces of that
body. Units are Btu/h·ft2·°F (W/[m 2·K])
Thermal
energy
storage
(1 ) thermal energy storage may refer to a number of technologies
that store energy in a thermal reservoir for later reuse. They can
be employed to balance energy demand between daytime and
nighttime. The thermal reservoir may be maintained at a
temperature above (hotter) or below (colder) than that of the
ambient environment. The principal application today is the
production of ice, chilled water, or eutectic solution at night,
which is then used to cool environments during the day. (2)
thermal energy storage technologies store heat, usually from
active solar collectors in an insulated repository for later use in
space heating, domestic or process hot water, or to generate
electricity. Most practical active solar heating systems have
storage for a few hours to a day's worth of heat collected. There
are also a small but growing number of seasonal thermal stores
used to store summer heat for space heating during winter
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Thermal
expansion
increase in one or more of the dimensions of a solid body or a
liquid volume, caused by a temperature rise
Thermal
resistance (Rvalue)
the reciprocal of the time rate of heat flow through a unit area
induced by a unit temperature difference between two defined
surfaces of material or construction under steady-state
conditions. Units of thermal resistance are h· ft2· °F/Btu (m 2· °K/W).
Thermal resistance is the reciprocal of the thermal conductance
Thermostat
an automatic control device used to maintain temperature at a
fixed or adjustable setpoint
Thermostatic
control
an automatic control device or system used to maintain
temperature at a fixed or adjustable setpoint
Three-way
valve
valve having either a single inlet and two outlets (diverting) or two
inlets and a single outlet (mixing), in which either one or the other
is open. Can also be a service valve for dual-mounted safety
relief valves. See also diverting valve
Tolerance
difference between upper and lower limits of size for a given
nominal dimension or value
Transducer
(1 ) a device designed to receive energy from one system and
supply energy, of either the same or of a different kind, to
another system in such a manner that the desired characteristics
of the input energy appear at the output. (2) a device that
changes one form of physical quantity into another. In the
measurement field, transducers are generally used to sense a
variety of measurands, such as line voltage, current, power,
pressure, and temperature, and to convert these to a common
output signal for use with a controlling or recording instrument
Transfer air
air transferred from one room to another through openings in the
room envelope, whether it is transferred intentionally or not. The
driving force for transfer air is generally a small pressure
differential between the rooms, although one or more fans may
be used
Two-way
valve
valve having a single inlet and single outlet. Uses of two-way
valves could be for throttling, isolation, or shutoff
Unconditioned
space
space within a building that is not conditioned space
Unitary
system
one or more factory-made assemblies that normally include an
evaporator or cooling coil and a compressor and condenser
combination
Use factor
percent capacity realized over a period of time that a system
is operated
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Variable
refrigerant
flow (VRF)
system
an engineered direct-expansion (DX) multisplit system
incorporating at least one variable capacity compressor
distributing refrigerant through a piping network to multiple indoor
fan-coil units, each capable of individual zone temperature
control, through integral zone temperature control devices and
common communications network. Variable refrigerant flow
utilizes three or more steps of control on common,
interconnecting piping
Ventilation
(1 ) the process of supplying air to or removing air from a space
for the purpose of controlling air contaminant levels, humidity, or
temperature within the space. (2) the process of supplying or
removing air by natural or mechanical means to or from any
space. Such air is not required to have been conditioned
Ventilation air
the minimum amount of outdoor air required for the purpose of
controlling air contaminant levels in buildings
Volatile
organic
compounds
(VOC)
organic compounds in the vapor state present in an indoor
atmosphere
Waste heat
(1 ) heat rejected from the building (or process) because its
temperature is too low for economical recovery or direct use. (2)
unused heat rejected from a system, usually a heat engine or
combustion furnace, to its surroundings
Water
economizer
a system by which the supply air of a cooling system is cooled
indirectly with water that is itself cooled by heat or mass transfer
to the environment without the use of mechanical cooling
Wind chill
the apparent temperature felt on exposed skin due to wind. The
degree of this phenomenon depends on both air temperature and
wind speed. The wind chill temperature (often popularly called
the wind chill factor) is always lower than the air temperature for
values where the wind chill formula is valid. In cases where the
apparent temperature is higher than the air temperature, the heat
index is used instead. Wind chill is always expressed as a
temperature. Compare to chill factor, which is always expressed
as time
Zoning
division of a building or group of buildings into separately
controlled spaces (zones), where different conditions can be
maintained simultaneously
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