A Case for Building Commissioning
November 26, 2015
A Case for Building Commissioning
by: Mel James
July 6, 1994
Building consists of complex architectural, structural, mechanical and electrical systems. They are designed to provide a comfortable environment for the people and machines that work and operate within the building.
With so many complex systems, building owners generally agree that a commissioning process is necessary to successfully bring the building design through the construction stage to occupancy. However, there is no general agreement as to what the commissioning process should consist of. What should be provided by the design consultants and the contractors? Should there be an independent commissioning agent? Should the commissioning agent be a division of the design consultant that specializes in providing commissioning services? When should the commissioning process start and finish?
These questions are asked of us by building Owners. We recognized their concerns, and in 1989 we formed a division of Smith and Andersen that specializes in providing commissioning services for mechanical systems, and in 1992 formed a separate company, Commissioning & Facilities Management Services Inc.
Before we answer these questions it is important to review why these questions are being asked. Twenty years ago the commissioning process was provided by the design consultants. Often the projects warranted a site engineer who supervised and performed the commissioning services.
These services were gradually removed from the design consultants responsibility, predominantly to reduce the cost of the project, but also because it was felt that contractors could perform the commissioning services and that the building owners operating staff would verify mechanical system operation during the warranty period. This process was originally successful, however, over time, without a clear commissioning procedure, the building owners began encountering many problems after a project had been completed. They found it difficult to get the contractors back to correct a problem. A better commissioning process was necessary.
All parties involved in building design, construction and management have recognized that the complexity of the building systems have increased dramatically over the twenty years and that the commissioning process must address not only the quality of the building systems design and installation but also the needs of the building operation and the people and machines that occupy the building.
The questions raised, can be categorized as follows:
1. When does the commission process start and finish?
2. What is the commission process and its goals?
3. Who should provide the commissioning service?
We will answer these questions using the experiences we have gained commissioning mechanical and electrical systems in small and large buildings since 1989.
1 WHEN DOES THE COMMISSIONING PROCESS START AND FINISH?
We recommend that the building owner establish that a commissioning process be part of the project when they are negotiating their contracts with the architects and consultants. At this time, they should also establish what the commissioning process will consist of, who will conduct the service and who has overall responsibility.
The commissioning process should begin when the design intent for the building has been established. The commissioning agent will use the design intent data to verify that the systems recommended will provide the intended performance for the building.
The commissioning agent will provide assistance to the design consultant during the design stages to ensure that the specification clearly outlines the commissioning process and the responsibility of the contractors, design consultants, and the commissioning agent.
During construction the commissioning agent will witness contractor tests and conduct independent tests to ensure the installation meets the specification and design intent.
Prior to building acceptance the commissioning agent will conduct operation training sessions for all equipment, system operating procedures, and maintenance procedures.
During the first year of operation, the commissioning agent will continue the dynamic testing process and provide additional building operator training.
The commissioning process will end after the first year of operation and when the goals of the commission process have been achieved.
We strongly recommend that the building owner’s representative take an active role in the commissioning process. The knowledge gained will be invaluable.
2 WHAT IS THE COMMISSIONING PROCESS AND ITS GOALS?
The commissioning process and goals should be customized for each building. The process and goals should be clearly identified in the contract between the building owner, the architect, the consultants, and the commissioning agent.
The commissioning process we recommend is as follows:
2.1 DESIGN STAGE
There must be close co-operation between the architect, the design consultants, and the commissioning agent to ensure a smooth flow of information and to ensure the success of the process.
During the design stage the commissioning agent will:
- Review the design intent.
-Prepare the commissioning plan.
-Work with the design consultant to prepare the commissioning section of the specification.
- Prepare the equipment and installation verification forms and static and dynamic testing forms.
- Prepare the testing scheduling forms to be used by the contractors.
2.2 CONSTRUCTION STAGE
It is essential during the construction stage that the commissioning agent develops a good working relationship with the contractors, manufacturers, architects and design consultants. When problems are uncovered the commissioning agent should provide assistance to correct the problem.
During the first commission meeting the commissioning agent should make it clear that they represent the building owner. The commissioning process is designed to assist the construction process and to reduce the installation deficiencies and call backs.
At subsequent commissioning meetings the results of the commissioning process are reviewed.
During the constructions stage the commissioning agent will:
- Review shop drawings after the design consultants have reviewed them.
- Verify that the data meets the design intent and the specification.
- Conduct commissioning meetings with the contractors.
- Prepare an issue minutes.
- Add dates to the testing scheduling forms.
- Conduct installation inspections.
- Verify that the equipment and installation meets the design intent and the specification.
- Witness the scheduled static and dynamic tests.
- Work in conjunction with the design consultants to review the acceptance test process conducted by the contractor.
- Prepare deficiency reports and issue to the design consultants and the building owner.
- Prepare a commissioning report and submit copies of all test and verification forms.
2.3 DYNAMIC TESTING OF THE MECHANICAL AND ELECTRICAL SYSTEMS
The commissioning agent will begin this process after the systems have been accepted by the design consultants. They dynamic tests will be designed to check the performance of each system using the building and outside air loads that are available.
The central energy management system (CEMS) will be used extensively during this process to check out the performance of the mechanical and electrical systems and to monitor and record the results of the dynamic tests.
The control setpoints and loops will be fine tuned to obtain stable comfort conditions in the tenant areas.
The electrical sub-systems will be load tested; this will include load balancing and harmonics testing where required.
The commissioning agent will work closely with the contractors, manufacturers, and the design consultant during these tests. All parties will be notified of deficiencies immediately with the recommendations where appropriate.
2.4 BUILDING OPERATOR TRAINING
The Mechanical and electric systems in buildings are complex. The commissioning agent should place a great deal of emphasis on operator training to ensure the proper operation and maintenance of the systems.
The commissioning agent will provide the following:
- Manage the training that is to be provided by the contractors and manufacturers.
- Ensure that each training session is planned and documentation is available.
- Video tape the training sessions.
- Provide additional training which covers the design intent and overall system operation.
- Prepare a design and operational manual and review the document with the building operators.
- Assist the operators in preparing a maintenance management program.
The system operational manual and video tapes provide a permanent record to be used by the building operators at any time. They also provide a valuable source of information for new building operators.
2.5 FIRST YEAR OPERATIONAL SUPPORT
This is a critical time for the building operators. The mechanical and electrical systems have been handed over to them and the occupants are moving in. The contractors and the design team have moved out of the building. The commissioning agent continues the commissioning process to provide operational and training support. The commissioning agent continues to check the operation of the systems during this period and to dynamically test the equipment as the seasons change and the occupancy increases.
Twelve months after mechanical system acceptance the commissioning process will end. The mechanical systems will have been checked thoroughly, and design and installation deficiencies corrected and system performance verified with the design intent. The commissioning agent will issue a final report, update the as-built drawings, and the system operational manual.
3 WHO SHOULD PROVIDE THE COMMISSIONING SERVICE?
The building owner may choose to provide the commissioning service themselves, have the design consultant provide the service, or an independent commissioning agent provides the service. The final choice will depend on who has the resources and experience to provide the most efficient and productive service and who will work with the contractors, design consultants, and building owners most effectively.
As a company specializing in commissioning we obviously recommend that a independent commissioning agent provide the commissioning services. The experience and organization required to provide these services is substantial. The organization must specialize in providing commissioning services to successfully complete the process.
Whoever is hired, it is important to clearly identify the requirements of the contractor commissioning process in the specifications. The role an responsibilities of the commissioning agent must be identified with respect to the contractors and the design team. The commissioning agent must be able to balance along that fine dividing line of protecting the owner’s interest and working with the contractors and design team.
To ensure that the quality and efficiency of a building’s systems are delivered before occupancy a commissioning process is necessary. The process should begin at the conceptual stages and follow through to the first year of operation.
The benefits of the commissioning process for a building owner are:
- The equipment and installation has been thoroughly inspected to ensure that the quality of the specification and building code requirements have been met. This reduces the risk of equipment or installation failure which may affect the building operation.
- The dynamic testing process fine tunes the mechanical and electrical systems during the seasonal changes. This process proves the systems can produce the intended environmental conditions of temperature, humidity, ventilation rates and air quality. This eliminates the trial and error period. The occupants move in to a comfortable environment. This will have short and long term positive effects with the building and the occupants’ relationship.
- The training sessions and operational manual ensure the building operators are well trained in all the operational aspects of the systems. They are better prepared to adjust to the needs and respond in a sensitive but positive manner. Again this will have short and long term positive effects.
- The training sessions will also help the building operators set up efficient maintenance programs. These programs will reduce the risk of equipment failure and help protect the investment of the building owner.
- The first year of operation support provides valuable assistance to the building operators. It helps to ensure the design conditions are being maintained and that the equipment is operating to the design efficiency. This in turn helps to maintain environmental conditions for the building occupants and control the energy cost.
In conclusion, the commissioning process for a building provides a benefit both to the building owner and prospective occupants. The process provides an added level of assurance that the environmental quality of the building and the mechanical design efficiency will be delivered.