Manual J8® Training Materials
Donald Prather
Technical Services Specialist
Air Conditioning Contractors of America
HVAC Excellence National HVACR Educators – Trainers Conference & Expo
March 18-20th, 2013 Las Vegas, NV
The Air Conditioning Contractors
of America (ACCA)
The only nationwide association representing
the technical, educational, and policy interests
of U.S. businesses that design, install and
maintain indoor environmental systems
ACCA History
National Warm Air Heating and Air Conditioning
Assn. (1914)
Air Conditioning and Refrigeration Contractors of
America (1946)
National Environmental Systems Contractors
Assn. (1968)
Air Conditioning Contractors of America (1969)
Don’s History
Maryland 1st Class Stationary Engineer
Licensed HVAC Contractor in Florida
BS Mechanical Engineering Technology
Thomas Edison State College
ACCA Technical Service Manager
How Many Here Teach Manual
J8 Load Calculations?
126 Pages
556 Pages
250 Pages
Manual J7
Hand Sheets
vs
Manual J8
Hand Sheets
vs
Manual J7
Hand Sheets
vs
Manual J8
Hand Sheets
vs
ACCA Instructor Power Point
The intent of this series of MS Power
Point® presentations is to provide
instructors with varying levels of
experience the building blocks to teach the
residential HVAC design process over a
wide variety of time frames.
ACCA Instructor Power Point
The material was designed to be used by
time-strapped instructors familiar with
Manual J7 who need course material to
transition to the new Manual J8ae.
ACCA Instructor Power Point
This step-by-step training material can be
opened, modified, adapted, or changed to
meet your needs. It can be pared down to
a condensed overview of the residential
HVAC system design process, for a full
week of training as is, or expanded into a
full semester or by adding case studies or
additional examples, this material could
cover a full school year.
ACCA Instructor Power Point
ACCA also thanks the following for their
recommendations and comments which
sharpened the presentations even further:
–
–
–
–
–
–
–
Jack Bartell; Virginia Air Distributors
Glenn Hourahan, PE; ACCA Staff
Warren Lupson; Lupson & Associates
Hank Rutkowski, PE; HTR Consulting
David Swett; Omaha Public Power
Richard Welguiucz,; The Trane Company
Wes Davis; ACCA Staff
First Chapters of J8ae
Instructor Complaint:
“In Manual 7 we start with interesting stuff:
the real meat! By the time I wade through
the first two chapters of Manual J8ae I
have lost my class.”
First Chapters of J8ae
I will now try to briefly cover the pertinent
information from the first two chapters in a
quick and interesting way using the actual
12 slide presentation and a one page hand
out summarizing the exceptions.
First Chapters of J8ae
This will be a little challenging because
you are not students so please have some
patience if it seems I am covering stuff that
you all know how to do better than I do.
Drum Roll Please!
Residential Load
Calculation
Introduction
Miscellaneous Items
•Cell/mobile phones and pagers
– Please turn off or set on vibrate mode to minimize
disruptions to class
– Please take cell phone conversations outside the
training room
•Smoking stations outside
– Not permitted inside the training room
•Restroom locations
Class Objective
To provide the attendee a basic understanding of
heat gain and loss calculations principles in Manual
J8ae, to enable him or her to correctly use manual
worksheets or the software calculation procedure on
the spreadsheet in back the of manual.
Introduction
“Long term success in the
residential comfort system
business depends a great deal on
how well system capabilities
match customer expectations. To
accomplish this, contractors
must work with the client first to
establish realistic expectations
and second to install a system
that performs to those
expectations.”
Client Interview
Do the contractor and the
client have the same vision?





Heating and cooling
Temperature on each floor
Humidity control
Filtration and air quality
System efficiency & operating
cost
 Health and safety (mold, mildew
& back drafting issues)
 Building code compliance
Drawing Used with
permission from HARDI
System capability
The system must be compatible with
negotiated list of performance criteria.
– System concept (# of zones, single or two stage, etc.).
Drawing Used with
permission from HARDI
Benefits of an Accurate
Load Calculation
 Provide specified comfort & humidity control at
design conditions.
 Provide acceptable comfort & humidity control at
part-load conditions.
 Provide reasonable comfort at outdoor design
conditions.
 Reduce the possibility of indoor mold and mildew.
 Optimize installing cost.
 Reduce operating cost.
 Improve reliability.
Drawing Used with
permission from HARDI
Benefits of an Accurate
Load Calculation cont.
 Translate to smaller equipment.
 Translate to smaller duct airways and increased duct
system efficiency.
 Minimize service loads imposed on utility grids.
 Translate to competitively priced proposals and
quotes.
 Minimize “surprises” after the system is put into
operation.
 Demonstrate “due diligence” in a court of law.
 Provide design values for sensible & latent
equipment capacity.
Consequences of Failing to
Make a Detailed and Accurate
Load Estimate
 Cause discomfort during design-day weather.
 Produce marginal or unacceptable comfort at partload conditions.
 Reduce the equipment’s ability to control indoor
humidity.
 Cause short cycling effecting comfort, operating cost
and reducing equipment life.
 Translates to large of equipment and ducts.
 Increased installed cost resulting is less competitive
quotes.
 Increases loads on utility grids.
 Awkward position in a court of law.
Business Issues
 Your client is important.
 You are selling quality, performance and
dependability.
 The comfort system is professionally designed and
exceeds minimum standards and practices.
 Money spent on design work is a far better
investment than money spent on excess capacity.
 You are providing value-added work.
 You can be trusted to do things the right way.
 You show you care.
 You make money.
The End
Residential Load
Calculation
Section 2 – Making an
Accurate Load Estimate
Miscellaneous Items
•Cell/mobile phones and pagers
– Please turn off or set on vibrate mode to minimize
disruptions to class
– Please take cell phone conversations outside the
training room
•Smoking Stations Outside
– Not permitted inside the training room
•Restroom locations
Making an Accurate Load
Estimate
•Preparation of forms and worksheets –
section 6.
•Survey - appendix 5.
•Protocols for estimating heating and
cooling loads.
– Manual J do’s (mandatory requirements).
– Manual J don’ts (mandatory
requirements).
Preparation of Forms and
Worksheets
•Order of procession for block load estimate
– Worksheet A: design conditions
– Worksheet B – C: window, glass
doors & sky light loads
– Worksheet D: opaque surface
loads
– Worksheet E: infiltration loads
– Worksheet F: internal loads
– Worksheet G: duct loads
– Worksheet H: ventilation loads
– Form J1ae: room load estimates
Manual J do’s
(mandatory requirements)
Use outdoor design conditions recommended
by table 1 manual J.
Use the default indoor design conditions
recommended by manual J.
Consider orientation of the structure on the
site.
Verify all construction details prior to
calculating loads.
Take full credit for all internal shading devices
and external overhangs.
Manual J do’s
(mandatory requirements)
Use internal shading devices that are
compatible with the type of room.
Take credit for insect screens when installed
or specified.
Take full credit for rated performance of
construction materials, insulation and
construction features.
Take full credit for tightness of of the envelope
construction.
Follow the manual J procedures for infiltration
and ventilation.
Manual J do’s
(mandatory requirements)
Take full credit for duct system sealing and
insulation.
Match location as close as possible when
selecting a duct load table.
Match duct supply and return system
geometry.
Use the correct R-values for duct wall
insulation.
Add blower heat to the sensible gain if
equipment performance data is not adjusted
for blower heat.
Manual J Don’ts
Do not use Manual J for commercial
applications.
Do not use MJ8ae to estimate loads not
compatible with the overview for this manual.
Do not design for record breaking weather
conditions.
Do not add a “safety factor” to table 1A.
Do not design for abnormally low or high
indoor temperature or humidity conditions.
Do not assume there is no internal shading.
Do not fail to take full credit for overhangs.
Manual J Don’ts
Do not assume that the load for the worstcase site orientation can be used for other
orientations.
Do not reduce known ceiling, wall or floor
R-values “just to be safe”.
Do not fail to give full credit for the builder’s
effort to produce a tight envelope.
If a local code specifies a fresh air
requirement, do not assume the infiltration
rate will satisfy this requirement.
Manual J Don’ts
Do not assume that windows and doors will
be open when making the infiltration
estimate.
Do not make worst case “everything is
going full blast” assumptions about internal
loads.
Do not add extra occupancy loads for
“entertaining groups of people.”
Do not add internal loads for special events.
Manual J Don’ts
Do not arbitrarily assume that ducts are
unsealed.
Do not fail to give full credit for efforts to
provide tight, properly insulated ducts.
Do not apply “safety factors” during any
stage of the load calculation process.
Do not apply a “safety factor” to the final
answer or to the equipment selection
procedure.
Making an Accurate Load
Estimate
•Improper practices. (Do not use “rules-ofthumb”)!
•Know your software and read the MJ8 text!
•Using software for manual J calculations.
•Conclusion.
THE
END
Principles of Math: Appendix 4
J8ae
This section should be covered sooner
rather than later and will help students
who need a quick math review as well as
students that need to learn a little about
building construction and materials..
Residential Load
Calculation
Appendix 4 – Physical
Principles and
Mathematics
Miscellaneous Items
•Cell/mobile phones and pagers
– Please turn off or set on vibrate mode to minimize
disruptions to class
– Please take cell phone conversations outside the
training room
•Smoking stations outside
– Not permitted inside the training room
•Restroom locations
Course Objective
Understand the physical principles and
mathematics necessary to calculate the
heat loss and gain for a residential building
Physical Principles &
Mathematics Appendix 4
• References – pg.163
• Units of measurement
and measurements
protocols.
– Measured dimensions.
– Areas of building
components.
– Perimeters and
volumes.
Formulas
•Area (rectangle)= length x height
•Area (triangle) = base x height x 0.5
Formulas
•Gross area = rectangular + triangular area
•Volume of a box = length x width x height
•Triangular prism volume = length x width x height
x 0.5
Ceiling Area Calculation for
Sloped Ceilings
MJ8 Table A4-1 pg. 412
MJ8ae Table A4-1 pg. 164
Physical Principles & Mathematics
Appendix 4
•Temperatures dry bulb & wet bulb.
– Temperature scales (°F/°C).
 Based on affect of heat on water.
 Boiling and freezing points.
F = C° x 9/5 + 32
C = 5/9 x (F° - 32)
Drawings Courtesy of HARDI
Residential Load
Calculation
Appendix 4 – Physical
Principles and
Mathematics
How do We Measure Heat?
•Basic unit of
measurement is
British Thermal
Unit BTU.
•Amount of heat
to change 1 lb. of
water 1°F.
Drawing Courtesy of HARDI
Physical Principles &
Mathematics Appendix 4
•Sensible heat causes a
change in temperature
but no change in state.
– Types of sensible
transfer.
•Latent heat causes a
change in state but no
temperature change.
– Types of latent
heat transfer.
Drawings Courtesy of HARDI
Physical Principles &
Mathematics - Cont.
•Sensible and latent heat equations.
– Sensible Btuh = 1.1 x ACF x CFMx ∆T
– Latent Btuh = 0.68 X ACF X CFM X Grains
•Sensible Heat Ratio (SHR).
– SHR = Sensible cooling load Btu/h
Total cooling load Btu/h
Modes of Heat Transfer
Drawing Courtesy of HARDI
•Conduction - The flow of heat through a material,
or other material in contact with it.
Modes of Heat Transfer
•
Convection - The transfer of heat from a surface
to a liquid or gas or vice versa depending on
which is hotter.
Drawing Courtesy of
HARDI
Modes of Heat Transfer
•
Radiation - The transfer of energy by
electromagnetic waves.
Drawing
Courtesy of
HARDI
Physical Principles &
Mathematics - Cont.
Material properties - see table A1-3
– Thermal conductivity = 1/ R (resistance) per inch.
– Thermal conductance = Conductivity x Thickness
– Thermal resistance = 1/ U (conductance)
Physical Principles &
Mathematics - Cont.
•R-values pg. 170
– Table A1-3 R-values for materials.
– R per Inch = 1/ U value (conductivity) per in.
– Rt = R1 + R2 + R3 + R4 etc.
Physical Principles &
Mathematics - Cont.
Air film coefficient


Outside Air Film
Inside Air Film
R-Values for
Common
Construction
Materials
Table A4-3
pg. 184
Table A4-3
pg. 184
Table A4-3
pg. 185
Table A4-3
pg. 185
Pg. 171
R-Values for Common
Insulations
R-Values Compression
Adjustment
pg. 171
50%
R-11.5
R-Values for Common
Construction Materials
Physical Principles &
Mathematics - Cont.
Transmission coefficient pg. 172
U value = 1btuh per sq. Ft. Per hr.
Drawing Courtesy of
HARDI
Physical Principles &
Mathematics - Cont.
•
•
•
Whole panel u-values.
U-value estimate issues.
U-value calculations.
U value =
1___
Rt value
U value =
1__ = .07 BTU
14.45
Physical Principles &
Mathematics - Cont.
Drawing Courtesy of HARDI
•Temperature
and
temperature
differences
70°F - 0°F = 70°F TD
Physical Principles &
Mathematics - Cont.
•Daily range.
Physical Principles &
Mathematics - Cont.
•
Heat transfer multiplier (HTM)
HTM = U value X temp. Diff.
•
Heat loss HTM for opaque panels.
– Heat loss HTM for slab floors.
– Effective opaque panel gain.
– Heat gain HTM for opaque panels.
Physical Principles &
Mathematics - Cont.
•
Heat loss HTM for
fenestration, opaque panels.
– Effective heat gain for
windows and glass doors.
– Effective heat gain for
skylights.
•
Default heat gain HTM for
generic fenestration.
•
Overhang adjustment for
window and glass door HTM.
Physical Principles &
Mathematics - Cont.
•
Duct loads
Supply air moving through ducts
can experience a significant
temperature drop or rise resulting
in large loads for heating/cooling
units..
•
Duct sealing
Cooling Supply Ducts
passing through an
unconditioned space
must be insulated and
sealed with a vapor
barrier.
Drawings Courtesy of HARDI
Physical Principles &
Mathematics - Cont.
•Blower heat.
1,707 Btuh
•Moisture migration.
Drawing Courtesy of HARDI
Warm side
Moisture Migration
Cold side
THE
END
JUMP TO SECTION 6 PART 2
Residential Load Calculation
Room Load Estimate
Residential Load
Calculation
Section 6 (Part 2)
Room Load Estimate
Class Objective
Upon completion, the attendee should be able to calculate a
cooling and/or heating load for a residential single-family
structure using Manual J8ae, worksheets and a pocket
calculator.
ACCA House w/add
70
75
50
771
Valparaiso, IN
41
3
90
38
.
M
67
15
98
1165
Table 6A
Internal Loads
ACCA House w/add
Valparaiso, IN
70
41
M
75
3
67
50
90
15
771
38
. 98
3
We
will added up subForm
totals later.
Worksheet:
J1ae
(12 small,6 med & 4 large plants))
4
In RM
Loads
2400
1165
800
360
www.acca.org/speedsheet
FORM J1AE ● ABRIDGED VERSION of MANUAL J, 8TH EDITION
Project
ACCA
Design State & City
Indiana
Valparaiso
Indoor Design Heating db
70
@ Outdoor (Winter) 99% db
3
HTD
Indoor Design Cooling db
Indoor Design Cooling RH
75
50%
@ Outdoor (Sum m er) 1% db
Grains Difference
90
38
CTD
Daily Range
Elevation
771
Latitude
41
Glass
Direction
.
Construction Detail
ACF
Heating
HTM
Cooling
HTM
67
15
Medium
0.978
Net
Area
Block Load
Heating
BTUH
Cooling
BTUH
Room -->
Room -->
Net
Area
BTUH
Heating
Cooling
WAR
#DIV/0!
Net
Area
BTUH
Heating
Cooling
WAR
#DIV/0!
6A Window s
& Glass
Doors
6B Skylights
7
8
Wood &
a
Metal
Doors
b
c
Above Grade Walls
a
b
c
d
e
9
Partition Walls
f
g
Below Grade Walls
a
b
10 Ceilings
a
b
c
Partition Ceilings
d
e
11 Passive Floors
a
b
Exposed Floors
c
Slab (Perim eter Ft.)
d
Basem ent Floor
e
Partition Floors
12 Infiltration
f
g
Envelope Leakage
Average
No. of Fireplaces
Heated & Cooled
Floor Area = Sq. Ft.
Number of Bedrooms
13 Internal Gains
Above Grade = Cu. Ft.
3
#DIV/0!
Occupants
4
#DIV/0!
#DIV/0!
#DIV/0!
#VALUE!
#VALUE!
Appliance - 2400 BTUH
14 Sub Totals
#VALUE!
#DIV/0!
#DIV/0!
#DIV/0!
#DIV/0!
#VALUE!
#DIV/0!
#DIV/0!
#DIV/0!
#DIV/0!
#DIV/0!
#DIV/0!
#DIV/0!
#DIV/0!
7E-T&B SA in Attic, RA Riser in Floor to Ceiling Chase, Perimeter Supply Outlets
15 Duct Loss & Gain
16 Ventilation
R-Value = 6 Leakage Class .12/.24
Installed Square Feet of Surface or Default = 1
Supply
Combustion Air From Conditioned Space
Furnace
Water Heater
19 Blow er Heat Gain
0.142
1
0.149
Return
1
None
Manufacturer's performance data has no blow er heat discount
1707
20 Total Sensible Loss or Gain
#VALUE!
Latent Infiltration load for cooling
Enter Com pany Nam e Here
Enter Com pany Address Here
Enter Com pany City, State and Zip Code Here
Enter Company Phone Numbers Here
Enter Website or Em ail Address Here
21
Latent load for occupants
Latent load
Small
for plants
12
800
Medium
Large
6
4
360
Latent load for duct in unconditioned space
Latent ventilation load for cooling
221
Total Latent Gain
1381