IAQ Design Tools for Schools
- Commissioning Agent
- Cost of Commissioning
- IAQ Commissioning Checklist
- Checklist Introduction
- Sample Checklist
- Resources and References
Building commissioning is a quality assurance program intended to demonstrate the building is constructed well and performs as designed. If the building materials, equipment and systems weren't installed properly or aren't operating as intended, the health, productivity and other benefits of high performance design will not be achieved. Commissioning is a powerful tool because it can indicate if the designers and contractors have done what they’ve been hired to do. If commissioning reveals problems with design or construction, the district then has the authority to make the responsible parties fix the problems up front instead of dealing with maintenance problems or poor performance down the road.
In many ways, commissioning is similar to a "test run" or "systems check." It tests, verifies, and fine-tunes the performance of key building systems so that the highest levels of performance are achieved. Correctly implemented, commissioning is extremely cost-effective, and should improve the building delivery process, increase systems reliability, improve energy performance, ensure good indoor environmental quality, and improve operation and maintenance of the facility.
While all building systems can be commissioned, mechanical, electrical, and life safety systems are among the most important. Those systems having the greatest potential impact on indoor air quality in the school include:
- HVAC System
- Building Envelope
- Kitchen Equipment and fume hoods
The key elements of commissioning include:
- Installation checks. Check installed equipment to ensure that all associated components and accessories are in place.
- Operational checks. Verify and document that systems are performing as expected, and that all sensors and other system control devices are properly calibrated.
- Documentation. Confirm that all required documentation has been provided, such as a statement of the design intent and operating protocols for all building systems.
- O&M manuals and training. Prepare comprehensive operation and maintenance (O&M) manuals, and provide training for building operations staff.
- Ongoing monitoring. Conduct periodic monitoring after the school is occupied to ensure that equipment and systems continue to perform according to design intent.
Properly implemented, commissioning will ensure that a new school starts its life at the highest performance level possible. Building commissioning is a newly evolving practice and is becoming more widely used. It's therefore important that commissioning responsibilities — particularly who will bear the cost of correcting conditions that do not meet specifications — are clearly spelled out in the beginning of the design process.
Commissioning can take place for one building system or for the entire facility; however, the more comprehensive the commissioning, the greater the impact on school performance.
Commission key building systems.
- Engage a commissioning agent (the person responsible for implementing the commissioning plan) during the schematic design phase or earlier. The agent may be a member of the design team, an independent contractor, or a member of the school district staff;
- Collect and review documentation on the design intent;
- Make sure commissioning requirements are included in the construction documents;
- Write a commissioning plan and use it throughout design and construction;
- Verify installation and functional performance of systems;
- Document results and develop a commissioning report.
The commissioning agent is responsible for coordinating and carrying out the commissioning process. For complex projects, the commissioning agent should be brought on as part of the design phase. However, for most schools, commissioning may not be needed until construction start-up, and knowledgeable in-house personnel may fill the role of the commissioning agent. Commissioning should continue well into start-up, and be integrated into the operations and maintenance plan. The responsibilities of the commissioning agent include:
- Assisting with a clear statement of the design intent for each building system.
- Writing the commissioning specifications and incorporating them in the appropriate divisions of the construction specifications.
- Carrying out pre-functional and functional testing of all equipment and systems to be commissioned, using procedures designed in advance.
- Reviewing operation and maintenance (O&M) documents to be provided by the contractor.
- Developing O&M training curricula and materials to ensure they meet needs of O&M staff.
- Writing a final report including all commissioning documentation and recommendations for the owner.
Cost of Commissioning
For California schools, the cost of commissioning ranges between $0.10 and $0.30 per square foot of building area. Studies show that commissioning can be very cost effective, with simple paybacks ranging between four months and 20 months. (Gregerson, Joan. 1997. Cost effectiveness of commissioning 44 existing buildings.)
IAQ Commissioning Checklist
It is important that an independent check is performed immediately prior to occupancy to ensure that design and construction features that affect indoor air quality (IAQ) are properly installed and operating. At this point in time, all construction should be completed, all furnishings installed, and all mechanical systems should be properly operating. The building flush out should also be completed before commissioning. A post-occupancy check of the HVAC system is also desirable to ensure that the system is functioning as intended under actual occupancy conditions.
The commissioning agent records observations and measurements as recommended in the IAQ Commissioning Checklist. The Checklist will allow the agent to catch the most common design and construction errors regarding IAQ in schools. Once a problem is identified, the cause can be determined and repaired by professionals.
Ensure that proper precautionary measures are taken, such as turning off air handling units to prevent injury from electrical shock or moving parts, before performing internal inspections on the equipment, and taking precautions as needed to prevent falls.
Except for the airflow hood, the following materials are relatively inexpensive, and many of them are available from the facilities department of your school system.
- Commissioning Checklist - As many copies as needed to cover all the zones.
- Zone Map - Should be provided in the "Owners Manual"
- Inspection mirror
- Smoke pencil
- Relative humidity meter
- Airflow hood
- Hand tools - As needed to gain entry to air handling units
- Ladder - For airflow measurements on 2nd floor unit ventilators (if any)
Following is an example checklist with three zones completed. In this example, Zones 1 and 3 checked out as being ok, but Zone 2 has several problems: insufficient outdoor air supply, a dirty air handling unit, a musty smell, high relative humidity and inadequate documentation and training for O&M staff. The repair crew found that the cooling coil was clogged with construction dust and debris, preventing sufficient air flow and moisture removal. If this problem had not been identified, damage to library materials and to the health of occupants could have occurred.
Resources and References
- Collaborative for High Performance Schools (CHPS): CHPS has developed a best practices manual to help schools, districts and practitioners to achieve high performance design, construction and operation. www.chps.net/dev/Drupal/node
- Portland Energy Conservation, Inc.: Links to documents and organizations related to building commissioning and operation and maintenance - www.peci.org/model-commissioning-plans-guide-specifications
- American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), 1996. The HVAC Commissioning Process, ASHRAE Guideline 1-1996. www.ashrae.org
- U.S. Green Building Council. LEED 2.0 Reference Guide (for commercial buildings). www.usgbc.org