COMMISSIONING OF HVAC SYSTEMS FOR
IMPROVED ENERGY PERFORMANCE:
THE ANNEX 40 APPROACH
This paper is prepared for the International Short Symposium on HVAC Commissioning
Kyoto April 8 2003.
J.C. Visier
Centre Scientifique et technique du Bâtiment, CSTB, France, visier@cstb.fr
Note: This paper is based on work produced by the different participants to the annex40. Part of it are”cut
and paste” from the collective documents prepared within the annex and especially of the annex glossary of
terms.
ABSTRACT
The Energy Conservation in Building and Community Systems program of the International Energy Agency has set up a
research working group (Annex 40) on Commissioning of Building HVAC Systems for Improved Energy Performance. The
objective of this new Annex is to develop, validate and document tools for commissioning buildings and building services.
The paper describes the annex work at it mid term.
This work includes 5 tasks: 1) the commissioning process 2) manual commissioning tools 3) building energy management
system assisted commissioning tools 4) use of models for commissioning 5) commissioning projects.
In this paper the progresses on each subtask are described and a vision of what could be the final results is presented.
KEYWORDS
Building, energy, commissioning, HVAC
INTRODUCTION
The Energy Conservation in Building and Community Systems program of the
International Energy Agency has set up a research working group (Annex 40) on
Commissioning of Building HVAC Systems for Improved Energy Performance [1]. The
objective of this new Annex is to develop, validate and document tools for commissioning
buildings and building services.
One presents here the work program as well as the results achieved at the mid term of this
research group.
THE ANNEX 40 PARTICIPANTS
13 countries take part to the annex, 10 as full participant (Belgium, Canada, Germany,
Finland, France, Japan, Norway, Sweden, Switzerland, USA), and 3 as active observers (The
Netherlands, Korea, China).
A40-A-M5-F-CSTB-1
page 1/10
DDD/AGE n° 03-047C
The annex participants meet twice a year and the attendance to each meeting is between 30
and 40. The participants to these international meetings are mainly researchers coming from
research centers, universities and large companies. Shadow groups have been set up in
different countries in order to have a strong interaction with the professionals interested in the
annex work.
The participant list and contacts as well as much valuable information on the annex are
available on the annex web site www.commissioning-hvac.org .
WHAT IS COMMISSIONING
The definition chosen by Annex 40 is the following:
Commissioning is a documented way to diagnose and verify building system performance,
and to propose ways to improve the performance in compliance with owner’s or occupants’
requests. Commissioning is performed in order to keep the system in optimal condition
through the life of the building from viewpoints of environment, energy and facility usage.
The commissioning begins with pre-design phase and can be applied through life of
building including all phases, which are pre-design, design, elaboration, construction and
operation and occupancy phases.
This definition is a mix of American ASHRAE definition and Japanese SHASE definition.
It considers commissioning as a process and not as an action. This process goes along the
whole construction project. One shall note that commissioning is here described in a much
broader way than it is generally described in UK where commissioning is the advancement of
an installation from the stage of static completion to full working order to specified
requirements [2] .
One can differentiate: Initial Commissioning, Retro-Commissioning, Re-Commissioning,
On-Going Commissioning. The annex glossary which is now under final review defined them
as:
Initial Commissioning occurs during production of new building or system, and is defined
as systematic process beginning with program phase and ending with post-acceptance phase.
It is strongly recommended that the initial commissioning have consistency in the process. In
the case of installing new equipment in an existing building (e.g. installing a new cooling
system newly in an existing building which only has a heating system), it is referred to as
initial commissioning.
Retro-Commissioning means the first time commissioning being implemented in existing
building in which a documented commissioning was not implemented before. In many cases,
design documents of the existing building have been lost or unmatched with the current
situation. Therefore, the retro-commissioning process would include verification matters on
the design as shown in parts of initial commissioning.
Re-Commissioning occurs when building owner hopes to verify, improve and document
performance of a building system that has already had initial commissioning or retrocommissioning implemented in past. The re-commissioning is, in other words, a
commissioning implemented after the initial commissioning. Reasons to re commission a
building are diverse. It could be a modification in the user requirements, the discovery of
underperformance of the system, the wish to fix faults found during the initial commissioning
A40-A-M5-F-CSTB-1
page 2/10
DDD/AGE n° 03-047C
etc…. Periodic re-commissioning ensures that the original performance persists. Recommissioning is the event that reapplies the original commissioning in order to keep
building system performance in accordance with the design or current operating needs.
On-Going Commissioning is conducted continually for the purposes of maintaining,
improving and optimizing building system performance after initial commissioning or retrocommissioning and before degradation or disorder of the system goes too far. The large
difference between on-going commissioning and periodic re-commissioning is that recommissioning refers to the original building system performance, but on-going
commissioning lays emphasis on the performance optimization. On-going commissioning is a
successive commissioning process during operation and maintenance level to resolve
operating problems, improve comfort, optimize energy use, and recommend retrofits if
necessary.
WHY COULD COMMISSIONING DEVELOP IN THE FUTURE
Commissioning will probably develops in the coming years due to 1) Energy and
environmental reasons. Global warming has increased the pressure to reduce energy use in
buildings and many countries are willing to develop green buildings 2) Business reasons.
Many companies are developing new services to diversify their activities in the building and
energy industries 3) Technological reasons. Building automation systems are now standard in
recent buildings and are being installed in many older ones. These systems automatically
collect building and plant operating data, and offer possibilities for innovative commissioning
services.
Clearly, lack of awareness, lack of time and costs are the primary obstacle that impedes the
adoption of commissioning as a routine process for all buildings. Hence, efforts for
improvement should consider how new tools and organization can increase awareness of
commissioning interest and decrease the cost of delivering commissioning and/or
demonstrate the benefits obtained by performing commissioning.
ANNEX 40 GOAL AND ORGANIZATION
The objective of the Annex is to develop, validate and document tools for commissioning
buildings and building services. These tools include guidelines on commissioning procedures
and recommendations for improving commissioning processes, as well as prototype software
that could be implemented in stand-alone tools and/or embedded in building energy
management systems (BEMS). The work performed in the annex is focus on HVAC systems
and their associated control systems.
The annex includes also the test of the tools developed in real projects which will be used
to improve awareness of commissioning interest.
The Annex is organized according to the structure illustrated in Figure 1.
A40-A-M5-F-CSTB-1
page 3/10
DDD/AGE n° 03-047C
short term
long term
s
ol
to
g
g
in
in
n
n
io
io
ols
iss
to
iss
m
g
m
m
in
m
o
n
o
c
c
io
in
d
iss
e
s
t
l
m
sis
de
m
s
o
o
c
a
m
S
al
of
u
M
n
e
a
BE
M
Us
Commissioning process
Commissioning projects
Figure 1: Structure of Annex 40 work.
THE CX PROCESS
The first issue to describe the commissioning process is to define the tasks to be performed
to commission a building. This is important to clarify what is really covered by
commissioning activities. The tasks lists defined by the annex will help to define the tools
which are needed and where they can best be used.
The second issue consists in selecting the intensity of commissioning which is necessary
for a given building. The annex works on the development of a tool enabling to select for a
given project the intensity which will lead to a good cost ratio of commissioning activities.
The third issue consists in defining who will perform the commissioning tasks. We try to
describe different possibilities with their pro and cons.
The results of these activities consist in a series of customizable “standard models
commissioning plans” (SMCxP). These plans contain a detailed list of activities. Plans will be
defined for different type of building projects. The other tools developed within the annex
will help to apply one or more actions of the commissioning plans.
Commissioning tasks
The list of actions to be performed to commission a building could be quite long and it is
important to well structure it. The approach chosen in the annex is based on a Dutch tool
called “model quality control matrix”[3]. This matrix consists of columns corresponding to
project phases: pre-design, design, elaboration, construction and operation and occupancy
phases. It includes 9 lines corresponding to the different aspects of the task: definition of the
task, action to be performed, organization to perform the task, tools used to apply the task,
purchase and finance needed to apply it, documentation of the results, others… All actions are
located in one cell of the matrix.
A40-A-M5-F-CSTB-1
page 4/10
DDD/AGE n° 03-047C
A detailed description as well as tools can be linked to each matrix cell. An example of a
detailed task list developed within the annex is given below. This list is adapted to a complex
building.
Pre-Design
Develop Owner's Project Requirements
Scope and Budget for Cx
Appoint Cx Manager
Develop Initial Cx Plan
Identify Cx Team
Issue Periodic Cx Reports
Review Phase Activities
Design
Elaborate Cx Plan
Elaborate Cx Members and Roles
Write Cx Specification
Review Design Docs for Sys Manual
Review Design Intent
Review Maintenance Management Needs
Review Energy Budget
Review Phase Activities
Elaboration
Finalize Cx Specification
Check Energy and Envir for Life Cycle
Review System Manual
Develop Test Procedures and Forms
Develop Performance Forms
Update Cx Plan
Update Cx Members
Review Phase Activities
Realization
Update Owner's Project Requirements
On-Site Review of System Manual
Review Submittals
Conduct Cx Meetings
Coordinate Cx Schedule
Refine Cx Forms and checklists
Verify Training
Update Cx Plan
Update Cx Members
Review Phase Activities
Operation
Coordinate Seasonal Tests
Resolve Design/Construction Issues
Monitor Operational Benchmarks
Review Final As-Builts
Review Final System Manual
Prepare Cx Report
Update Cx Plan
Update Cx Members
Review Phase Activities
A40-A-M5-F-CSTB-1
page 5/10
DDD/AGE n° 03-047C
Evaluation
Final Cx Report
Identify Continuous Commission Tasks
Identify Unresolved Issues
Identify Desired Changes
Identify Cx Weakness Items
Identify Cx Improvements Items
Identify Warranty Action Items
Customized commissioning plan
The actions to perform to commission properly a building depend on the following
parameters:
Building owner and operator strategy: when the future user of the building is involved in
the project since the beginning, the approach chosen to look at future operation of the
building is much more detailed. So the effort put in commissioning can be much more
intensive.
Criticalness of building operation: laboratories, computer centre, industrial buildings,
headquarters are example of buildings where malfunction may have high economic or image
impacts. In such buildings the commissioning effort can also be more intensive than in
standard buildings.
Building and HVAC system complexity: The risk of malfunctions increases when one
moves from small heated buildings to large air conditioning buildings.
Packaged units/ systems: HVAC packaged units are mainly industrial products which are
selected for a given building. Distributed systems such has hydronic heating system,
centralized air conditioning systems include a set of industrial component connected through
air or water network to constitute a unique system. The risk of poor design and installation is
clearly higher with distributed system, so they do require more intensive commissioning.
The annex is developing a tool enabling building owners to assess rapidly the level of
commissioning needed for their project. This assessment will be the basis for the
customization of the commissioning plan which is necessary to reach a good cost benefit
ratio. 5 example of commissioning levels have already been defined which corresponds to :
1) Type 5: Complex critical building e.g.: a laboratory with complex HVAC systems and high
requirements on the indoor environment linked to the process in the laboratory
2) Type 4: Large commercial building with central HVAC system e.g.: an office building
including offices, meeting rooms, restaurant but without critical parts such as large
computer center
3) Type 3: Medium size building with central HVAC system e.g.: 20 apartments in one
building with a collective hydronic system and a collective mechanical ventilation system
A40-A-M5-F-CSTB-1
page 6/10
DDD/AGE n° 03-047C
4) Type 2: Medium size building with independent HVAC units e.g.: a store with roof top
package units
5) Type 1: Small size building with simple HVAC system e.g.: a detached house
Commissioning organization
The annex has performed an analysis of the different organization for commissioning.
Three main organizations can be differentiated.
In the first approach the commissioning tasks are performed by a commissioning authority
which depends only of the building owner and which is fully independent of the other players
in the construction process. This first approach warranties that a new eye is looking at all
aspects especially taking into account exploitation and maintenance issues. It gives a
maximum security to the owner. The main disadvantages are the extra costs for this new
activity and the risk of lower involvement of the other players in the quality aspects.
Commissioning addicts consider that these costs lead to high savings and that the cost benefit
ratio is very good.
In the second approach commissioning tasks are performed by the usual players: architects,
engineers, installers… This lead to a commissioning process much more embedded in the day
to day practice of these players. The challenge here is to well differentiate the commissioning
tasks from the usual design, installation, testing and balancing tasks. It is also to make the
building owner confident that these tasks are really performed. This confidence could be
obtained through a certification of the players by a third party. Different certification
procedures can be used. For single family houses the certification can be a certification of the
house itself. For larger project it is not manageable to certify the building which is the final
product, process certification seems to be an efficient way to get confidence.
The third approach is an intermediate one and consists in having most of the actions
performed by the usual players and to have a commissioning authority in charge of verifying
that they are effectively performed.
In a long term view the two first approaches could lead to very different perspectives. With
the first approach commissioning will become a work in itself with commissioning
specialists. So the success of people working in the commissioning field will be to have that
work recognized by the market. In the second approach commissioning could become a part
of each party work and is only a way to improve quality. Commissioning work will in this
second approach disappear as such and will only become common practice.
The annex is not discussing which approach or which mix of approaches is the most
adapted to different market situations but describes different possibilities.
MANUAL COMMISSIONING PROCEDURES
A lot of work has already been performed by different organization throughout the world to
develop checklists and performance testing procedures. The main challenge today is to make
the best use of existing procedures and to develop new ones only to suit uncovered issues.
The strategy of the annex consists in defining tools specifications then in transferring, when
possible, procedures from one country to others or in developing new procedures when
needed. When defining the tools specifications each tool will have to be located in the
A40-A-M5-F-CSTB-1
page 7/10
DDD/AGE n° 03-047C
standard model commissioning plans define above.
Main source of existing procedure have been located. The easiest access to US procedures
is given through a test protocol library [4].
The field of manual commissioning procedures is a very wide field and different groups in
the annex are concentrating on different topics.
A group is concentrating on procedures necessary to apply standard model commissioning
plans to simple buildings such as type 1, 2 and 3. Their focus is mainly residential building as
well as small non residential buildings.
A second group is concentrating on more complex air conditioned buildings (Type 4 and
Type 5 buildings).
BEMS ASSISTED COMMISSIONING TOOLS
Using the BEMS to commission the HVAC system is an attractive option. Three issues
have to be addressed to be able to implement this option. The first issue is the commissioning
of the BEMS itself. No chance to use the BEMS to commission the HVAC system if the
BEMS itself is not properly commissioned. The second issue is to define testing procedures
which can be automated. The third issue is to implement these procedures in the BEMS.
Regarding the commissioning of the BEMS itself enquiries were performed in three
countries to define what the main quality problems with BEMS are [5] [6]. From these
analyses a list of possible actions to improve BEMS commissioning by automating some
actions was defined. It covers the followings: 1) Simulation testing of control strategies on
test bench before installation 2) Automatic report generation when checking that all
equipments are installed 3) range check and auto calibration of input and output at panels 4)
Test local controllers a) self discovery of communication points b) auto tuning and closed
loop testing of control functions 5) Operator, workstation and supervisory controller set-up a)
auto tuning b) bump test of communication c) Check of supervisory strategies through closed
The work to automate existing procedures is performed mainly in national projects and the
annex appears to be the place to discuss and compare the different approaches. The teams are
deeply involved in the development of their own methods. A synthesis of the different
approaches has to be prepared but is not yet available. The development of each method has
to be more developed before it will be possible to prepare the synthesis.
Implementing automatic commissioning procedures in software and hardware raises
specific questions. Two types of procedures are possible. Passive monitoring procedures use
the BEMS to collect data about building and HVAC system behavior. Then algorithms are
applied on these data to determine if the behavior is correct or not. Active testing procedures
techniques not only monitor data but send test signal to the HVAC system. Such procedures
could include for example stopping and starting up plants, opening or closing dampers …
These procedures enable a much thorough testing of the system behavior but imply a two way
interaction with the system which is more complex to implement. Solutions to implement
passive monitoring as well as active testing procedures are studied within the annex. In
particular the possible hardware architectures and the use of open protocol such as Bacnet are
analyzed.
The final report of the annex will include a general description of possibilities and
A40-A-M5-F-CSTB-1
page 8/10
DDD/AGE n° 03-047C
difficulties of procedures for automation and a set of automated procedures tested during the
Annex.
It already appears that BEMS is more often used in on going or retro Cx than in initial Cx.
Indeed in many cases of initial commissioning the BEMS is operational at a too late stage to
be used for commissioning.
USE OF MODELS AND COMMISSIONING
The objective of this task is to evaluate the feasibility of using computer simulation based
on models to verify the performance of subsystems and whole buildings.
The work on component is focus on methods for performance evaluation of air handling
units. The goal at the component level is to use models of HVAC equipment to represent
correct operation. They will be used to prepare functional testing and performance monitoring
procedure to be connected to SMCxP. The current work consists in building a library of
component models. It was agreed among the participants to document the stand alone models
using EES. Models will be developed for: terminal units, active cooled beams, chilled
ceilings, fan coils, vav boxes, free chilling systems, and for components of AHU (mixing box,
heating and cooling coil), chillers, cooling tower, pump and pipe system, ice storage systems,
boilers, sensors. A list of issues to be addressed regarding models was defined.
The global vision of the steps to use models at the component or sub system level is the
following:
1. For automated functional testing, the model is configured using manufacturers'
performance data and system design information. In general, the model parameters will
be determined by a combination of direct calculation and regression.
2. An active test is performed to verify that the performance of the component is acceptably
close to the expected performance. This test involves forcing the equipment to operate at
series of selected operating points specifically chosen to verify particular aspects of
performance (e.g. capacity, leakage).
3. The test results are analyzed, preferably in real time, to detect and, if possible, diagnose
faults.
4. If necessary, the test is performed again to confirm that any faults that resulted in
unacceptable performance have been fixed. Once the results of this test are deemed
acceptable, they are taken to define correct (i.e. acceptable) operation.
5. The model is re-calibrated using the acceptable test results.
6. The tool is used to monitor performance during on-going operation. This will typically be
done in passive mode, though active testing could be performed at particular times, e.g.
every weekend, after routine maintenance, after system modifications or retrofit, on
change of ownership …
Regarding the use of models to perform commissioning tasks at the whole building level
three main approaches seems promising. The first approach consists 1) to use simulation
models developed during the design stage to predict heating and cooling use, 2) to compare
with measured use 3) to use signature of deviations as clue to sources of deviations. This
approach is adapted to initial commissioning. The second approach is more adapted to
continuous commissioning. It consists in using simulation models calibrated during the initial
commissioning phase. Simulated consumptions are compared to real consumption and
A40-A-M5-F-CSTB-1
page 9/10
DDD/AGE n° 03-047C
deviations serve as alarm for changes. The third approach consists in using the simulation
software as a test bench to assess the possible impact of changes in the control strategy.
COMMISSIONING PROJECTS
These projects will be used to test the tools developed within the annex as well as to
demonstrate the advantage of commissioning. About 20 projects are already selected in North
America, Europe and Japan a synthetic description of the projects acre available on the annex
web site.
CONCLUSIONS AND PERSPECTIVE
Commissioning is a promising approach to improve the actual energy performance of
HVAC systems. Applying commissioning needs at the same time 1) a clear definition of task
to be performed, 2) a clear task assignment between the parties involved in the building
project and the commissioning authority 3) a good toolset to help applying the different tasks.
After having clarified the tasks to be performed for different types of building project Annex
40 is now developing new tools to be included in a coherent tool set.
REFRENCES
[1] Annex 40 work program, www.commissioning-hvac.org
[2] CIBSE, Commissioning Code, Air distribution systems, Code A : 1996
[3] P. Op’t Veld, P. Ramsak, Model Quality Control and commissioning for HVAC
systems, Annex40-A-1-NL-CH, September 2001
[4] Kenneth Gillespie, A Commissioning Test Protocol Library, Pacific Gas and electricity,
http://www.cacx.org/projects/infra_2.html
[5] P. Gruber, R. Meisinger, Commissioning challenges for a control manufacturer’s point
of view, in IEA Annex 40, meeting in Quebec, 26-28 September 2001, CSTB report
DDD/AGE-2001.156U.
[6] H. Vaezi Nejad et al Enquiry on BEMS Commissioning Practices and user needs in
France, in IEA Annex 40, Meeting in Scheveningen, 5-6 April 2001, CSTB Report
DDD/AGE 2001-155U.
A40-A-M5-F-CSTB-1
page 10/10
DDD/AGE n° 03-047C