Commissioning
buildings, systems using
ASHRAE Standard 202
ASHRAE Standard 202-2013 was recently released, which offers
guidance on the building commissioning process.
BY TERRENCE MALLOY PE, CxA, exp US Services Inc., Chicago
Learning
objectives
Gain a basic understanding
of the commissioning process.
Learn about ASHRAE Standard 202.
Examine some real-world
examples of why commissioning is needed.
W
e hear a lot about commissioning (Cx) and retro-commissioning (RCx) these days, but what
do we really know about it, and what standards do we use to ensure that it is done correctly? ASHRAE’s answer to that question is
the 2013 edition of ASHRAE Standard 202:
Commissioning Process for Buildings and
Systems. Its purpose is to ensure the proper
procedures, protocols, and documentation
are used in the completion of all building
Figure 1: The energy consumption of the large VAV air handler before implementation
of any control changes is shown. All graphics courtesy: exp U.S. Services
26
Consulting-Specifying Engineer • DECEMBER 2013
and systems commissioning. It identifies the
minimum acceptable commissioning process that must be used.
The standard was developed by taking
best practices from ASHRAE Guideline
0-2005, The Commissioning Process,
which was first published in 1989 and then
revised in 1996. The current Guideline
0-2005 was compiled by ASHRAE and
the National Institute of Building Sciences
to provide the guidelines for a universal
commissioning process.
Standard 202 is designed to benefit the
building industry by ensuring that all participants follow the owner’s process for
verifying and documenting that the performance of buildings and systems meets
defined criteria. The standard was officially approved by ASHRAE at its June
2013 meeting.
This article will discuss the basics of
Standard 202-2013, but more importantly
provide several examples from recent RCx
projects that show that commissioning
really is needed.
In summary, the standard describes
the commissioning process, the role of
the commissioning authority (CxA), and
a framework for developing the owner’s
project requirements (OPR), basis of
design (BOD), commissioning plan, speciwww.csemag.com
Incomplete testing and evaluation
of VAV system requires reset
fications, procedures, documentation, and
reports. This standard also describes the
general requirements for a training program for continued successful system and
equipment performance. It addresses the
need for a document with more detail and
content than was previously available.
Whereas Guideline 0-2005 provided
suggestions and guides through the Cx
process, Standard 202 details the mandatory requirements of Cx that can be used
and adopted by code officials. The new
standard restates the same information
contained in Guideline 0-2005 and also
provides the minimum requirements for
the owner and the Cx team. It details the
mandatory role for the owner in defining
requirements and developing the OPR.
The main points are:
1. Purpose: The purpose is to identify
the minimum acceptable commissioning
process for buildings and systems.
2. Scope: This standard provides
procedures, methods, and documentation requirements for each activity for
project delivery from predesign through
occupancy and operation, including:
Overview of commissioning
process activities
Description of each process step’s
minimum activities
Minimum documentation requirements
Acceptance requirements.
4. Initiation of the
commissioning process:
The standard delineates
the owner’s responsibilities including CxA selection and development of
the OPR, and also lists
the overall Cx requirements.
A
n overhaul of the air handlers at a community college reaped
energy savings and improved occupancy comfort.
Through the local electric utility’s energy reduction program, exp US Services was hired to perform retro-commissioning of three of the buildings at a suburban community college.
Although the buildings were less than 10 years old, they were
not energy efficient and were a source of tenant complaints.
The buildings used three large variable air volume (VAV) air handlers with a total fan motor horsepower of 770 hp. The investigation of the HVAC systems revealed that the VAV boxes were never
properly commissioned, and the minimum settings were all above
the 50% flow setting. Each classroom had a designated VAV box,
but because the rooms were often sparsely occupied, these spaces were getting overcooled due to the high airflow. Additionally,
the school was paying a double penalty in that the reheat coils in
many of the boxes were coming on even in summer, to reheat the
overcooled spaces.
Through some minor changes in the building automation system
(BAS), the commissioning team was able to reset the VAV flow minimums
to much lower settings, and in some cases to zero when occupancy
sensors signaled that the room was unoccupied, which was in keeping with the original design intent. The electric energy savings were
substantial, and although the engineers did not verify the gas savings,
it is estimated they were about 35,000 therms/year.
The facility provided utility data for the before and after periods of
September 2009 to August 2010 and March 2011 to February 2012
(see Table 1). This provided an excellent comparison of year-to-year
electricity usage and savings.
The Cx team installed amp loggers on an air handling unit (AHU-1),
and the before and after data are shown in Figures 1 and 2. It is clear
that the new VAV minimum settings allowed the AHU fans to drop to
less than 30% of their peak loads, whereas previously the minimum
load was never less than about 60% of the peak.
5. OPR: The standard states that the OPR
should be developed by
the owner and the CxA
during the pre-design
phase, and list all of the
systems to be commissioned. At a minimum,
the OPR should contain
the following:
Facility use and
operating schedule
Energy and efficiency goals
Indoor space
requirements such
as temperature,
ventilation, etc.
List of all systems/
equipment to
be commissioned
Project schedule
Testing and sampling procedures
Training requirements
Submittal requirements
Cx report format.
3. Utilization: The standard lists the required activities and related deliverables
that are produced. The primary ones are:
Activity
Deliverable
Initiate Cx process
Roles and responsibilities
Decide project requirements
Owner’s project requirements
Develop Cx plan
Cx process plan
Design approach to requirements
Basis of design
Set contractor Cx requirements
Cx specifications
Review design to requirements
Design review report
Review submittals
Submittal review report
Observe and test
Construction checklists and reports
Resolve issues
Issues and resolution log
Assemble systems manual
Systems manual
Conduct training
Training plans and records
Post-occupancy operation
End-of-warranty Cx report
Assemble Cx report
Cx report
www.csemag.com
OPR should be included in contract
documents for informational purposes,
and be updated regularly throughout
the Cx process to reflect any changes
necessitated by the owner.
6. Commissioning plan: This provides the organizational plan and requisite documentation including:
Overview of Cx
process specific to
the current project
Roles of the Cx
team
Cx activities and
schedules
List and formats of
all Cx evaluations and testing form
List of systems to be commissioned
and specific evaluation procedures
for each.
Consulting-Specifying Engineer • DECEMBER 2013
27
ASHRAE Standard 202
shall provide a design review report with
comments, questions, and observations to
the owner and design teams for compliance with the OPR. This design review is
not design peer or code review.
10. Commissioning submittal
review: The Cx team shall perform a
review of the requisite submittal documents for all systems being commissioned, to ensure that they comply with
the OPR. The CxA shall submit a written
report to the owner and design authority.
A copy of this review shall be included in
the final commissioning report.
Figure 2: This shows the energy consumption of the large VAV air handler after implementation of the recommended control changes.
7. BOD: The BOD lists the design
team’s approach to meeting the OPR,
and provides the owner with a better understanding of the design issues.
The BOD is submitted by the design
team to both the owner and the
CxA and should contain:
Design assumptions and attention
to the OPR
Consideration of design alternatives
opportunities for improved
performance
Proper location of equipment
Coordination of applicable
technical and code requirements.
8. Contractor and supplier requirements: The applicable Cx process specifications and requirements shall be
included in all contracts with contractors, subcontractors, suppliers, service
providers, and manufacturers for the
systems and equipment being commissioned. Contractors, suppliers, etc., shall
provide the required documentation
as defined in the contract documents.
Examples of these documents include
submittals, shop drawings, installation
28
manuals, operations and maintenance
(O&M) manuals, and existing conditions
documentation.
9. Design review: The CxA shall perform a review of the design documents
to ensure that they comply with the OPR
before construction documents are issued.
A copy of this review shall be included in
the final commissioning report. The CxA
11. Construction observation and
testing: The proper installation, operation, and systems interaction shall be tested and verified for all equipment listed
in the Cx plan. This step in the process
shall consist of:
Systems evaluation including
detailed equipment information
such as model, serial numbers, and
name plate data, and condition of
equipment upon delivery.
Establishment of specific test
procedures and sampling quantities
for systems containing large numbers of components.
Execution of test procedures
repeated as often as needed until
systems are in compliance with
Fan controls don’t measure up
T
he fan controls at an airport terminal had never been reviewed, and needed to be updated
with variable frequency drives.
During a recent inspection of the HVAC systems for a 1-million-sq-ft airport terminal, the exp
U.S. Services team noticed the installation of inlet vanes on about 35 of the variable air volume
(VAV) air handlers. This seemed particularly odd because the fans were only about 10 years old.
When the engineering team inquired about the installation, the client indicated it was a cost
issue and that at the installation time the inlet vanes were a cheaper control method than variable
frequency drives (VFDs). It seems that a proper design review by the CxA would have addressed
this issue, and perhaps suggested a lifecycle cost analysis (LCCA) to show the actual operating
costs of using the inlet vane controls versus VFD controls.
The recommendation: replace the inlet vanes with VFDs. Although a moderately costly option,
the annual savings are 2,360,000 kWh and $127,000. As a bonus, the state is offering incentives
of about $160,000, so the effective payback is around 3.7 years.
Consulting-Specifying Engineer • DECEMBER 2013
www.csemag.com
Table 1: Electricity usage
Pre-RCx electricity usage
Months
Usage (kWh)
Post-RCx electricity usage
Peak demand (kW)
Months
Usage (kWh)
Peak demand (kW)
Sept. 09
771,878
1,434
Mar. 11
529,538
1,059
Oct. 09
634,072
1,444
Apr. 11
520,226
1,076
Nov. 09
699,026
1,265
May 11
576,244
1,167
Dec .09
590,416
1,089
Jun. 11
626,308
1,162
Jan. 09
616,322
982
Jul. 11
767,057
1,730
Feb. 09
529,746
946
Aug. 11
755,127
1,673
Mar. 09
608,936
1,172
Sep. 11
741,862
1,794
Apr. 10
626,972
1,326
Oct. 11
639,417
1,260
May 10
629,940
1,201
Nov. 11
537,964
1,278
Jun. 10
779,401
1,488
Dec. 11
503,887
1,033
Jul. 10
956,229
1,566
Jan. 12
429,176
969
Aug. 10
833,145
1,521
Feb. 12
446,561
976
Total
8,276,083
15,434
Total
7,073,367
15,177
Table 1: The total annual electricity savings were 1,202,716 kWh and $91,960.
requirements. The CxA witnesses
and documents these tests.
n Any equipment or system that fails
to meet requirements in a timely
manner is assigned an issue number
and recorded in the issue and resolution log.
12. Issues and resolution documentation: The Cx team shall develop a formal issues and resolution log,
and document any open or continuing item from the Cx progress reports.
The log will list all continuing items
along with the person/organization
responsible for their resolution. The log
will be maintained throughout the project
until all issues are resolved, or accepted
by the owner.
13. Systems manual: This shall
provide the information needed to understand, operate, and maintain the building’s systems. It is provided to the owner
for training purposes, and should contain
the following:
n Executive summary
n Facility design and construction:
copies of OPR and BOD
n Building systems: equipment
specifications, contractor
www.csemag.com
submittals, manufacturers’ O&M
data
n Facility operations: equipment
operating schedules, control
sequences and setpoints, operating
plan
n Training: training plan and materials, training records
n Final commissioning report: Cx
plan, testing and evaluation reports,
design review report, and issues
and resolution log.
14. Training plan: O&M personnel and occupants shall be trained in the
operation and maintenance of the commissioned systems. The training plan
should contain:
n Outline of instructional topics
addressing the design, operation,
and maintenance of specific
systems and equipment.
n The location and minimum duration
of training sessions, along with the
instructors’ qualifications, and
training records.
n A copy of the plan shall be included
in the systems manual.
15. Post-occupancy operation:
The post-occupancy activities begin at
substantial completion and include any
delayed or seasonal testing not yet completed. Also, any warranty issues should
be dealt with at this time. The owner or
general contractor is responsible for contractor call-backs. At the conclusion of the
post-occupancy operations, the systems
manual, testing documentation, and final
Cx report shall be submitted to the owner.
16. Commissioning report: The
final Cx report shall summarize the Cx
process and building operations, and be
submitted to the owner. It shall contain
the Cx plan and results of that plan. An
executive summary will identify all systems commissioned and the location of
the final OPR and BOD documents and
project record drawings. It should also
contain the following:
n The final Cx process plans
n Copies of design and submittals
review reports
n A completed copy of the CxA evaluations and start-up and test forms
n Copies of all of the Cx progress
reports
n A copy of the issues and resolutions
log and descriptions of measures
taken for resolving all issues
n A list and explanation of any
Consulting-Specifying Engineer • DECEMBER 2013
29
ASHRAE Standard 202
systems that do not perform in
accordance with the OPR.
n A resolution plan approved by the
owner for any incomplete issues or
testing and the party responsible for
their resolution.
Cx in the real world
As important as the Cx process is,
in reality it is often not completed
thoroughly, if at all. The examples in
this article reveal projects in which
one or more of the critical commis-
Snowmelt system controls
adjusted to save energy
A
t this large office campus, the sidewalk snowmelt system had never been reviewed
or commissioned. During a recent retro-commissioning investigation for a large office
complex, exp U.S. Services learned that the boiler-heated glycol system used for snow melting
ran continually whenever the outdoor air temperature was below 38 F. NOAA weather records
revealed that while the temperature is below 38 F for about 2250 hours/year, the actual amount
of time of snowfall is only 580 hrs/yr. This difference of about 1,700 hrs represents the time the
snowmelt system is on when it doesn’t need to be.
Because large areas were covered by eight different snowmelt systems, the calculated annual
savings was 43,000 therms of natural gas and $21,000. This system was installed many years
before the popularity of commissioning, but this speaks to the need for retro-commissioning,
and/or at least a periodic review of control sequences and operations.
sioning process steps were not completed properly—or were omitted
entirely. The consequences of these
omissions became apparent in the
forms of high energy use, poor system operations, and occupant comfort complaints.
The four examples cited are
indicative of what we find almost
everywhere, and clearly indicate the
need for more complete and rigorous
commissioning. The new ASHRAE
Standard 202 provides an excellent
and straightforward manual from
which to complete the commissioning process.
Terrence Malloy is project manager for the energy solutions group
at exp US Services Inc. He focuses on energy conservation, retrocommissioning, and renewable energy
systems.
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