Do the Right Thing: The Importance of Commissioning, Controls, and TAB in Lab Buildings
In the world of tight budgets and quick timelines, commissioning and balancing too often fall victim to the project clock, and consequently owners/operators inherit facilities that cost more to operate, cost more to maintain, and occupants that suffer from poor and potentially dangerous environmental control.
Commissioning (Cx) and testing, adjusting, and balancing (TAB) are important to the long-term efficiency, performance, and operation of all buildings, but Cx and TAB are especially important in laboratory buildings. Limited and/or poorly conducted Cx and/or TAB can have lasting and potentially dangerous impacts in lab buildings.
In terms of commissioning, proper development and testing of the control sequences and ventilation rates, are critical to long-term performance and efficiency of the spaces. Labs with improperly or inadequately commissioned mechanical devices and sensors can result in unsafe, inefficient or unusable spaces.
Furthermore, TAB is important to not only the long-term building performance but also important to the commissioning process. With properly executed TAB, the commissioning agent, engineers and operators can be confident when reviewing airflow and water flow data and make informed decisions.
One unfortunate shortcoming in typical TAB procedures is that the terminal devices, particularly VAVs and air valves, only get tested at their design maximum airflow conditions. Because most systems are oversized and/or designed for extreme conditions, in practice they rarely operate at or near maximum flow, rather they often operate at or near their minimum or median flow range. Consequently, because they were not measured and balanced at these conditions, the airflows measured and reported at the building automation system, are often inaccurate, and therefore the control of the device suffers as does the space being served. This results in either under- or over-ventilated spaces, poor lab containment, excess energy, and improper pressure balances.
Current TAB and commissioning guidelines and standards need to be revised, especially for lab buildings, such that TAB minimum procedures require testing lab terminal devices across the full operating range. Also, commissioning verification procedures need to include verification of 100% of these devices.
In summary, it is incumbent upon the owners to ensure that the project design and construction teams allow for enough budget and time for the adequate and proper commissioning and TAB at the terminal devices as well as at the zone- and system- levels. Without doing so, they will likely be paying the price in multiple ways and at many times the upfront cost, over the life of the building.
- Review of industry standards for TAB and Commissioning and recommended Improvements
- Understand the role of the Testing, adjusting, & balancing (TAB) contractor in verifying laboratory safety and optimizing operating costs
- Understand the role a commissioning agent has in the design, construction, operation, verification, and training of staff in new construction or major renovation
- The impact of proper commissioning and TAB on laboratory buildings on the long-term safety, performance, operating costs of lab buildings and the wellbeing of its occupants
Chris is a Vice President with B2Q Associates and is a mechanical engineer with a Masters of Science in Engineering from the University of Dayton, with a focus in commercial and industrial building energy efficiency. He has over 17 years experience working in building efficiency, HVAC mechanical and controls systems optimization, re-commissioning, and project management and he co-teaches the Association of Energy Engineers Existing Buildings Commissioning course.
Brad is a Project Manager with B2Q Associates and is a mechanical engineer with a Master of Science in Engineering from the University of Massachusetts, with a focus in industrial building energy efficiency. He has over 4 years of experience working in energy efficiency, controls systems, project oversight, implementation and commissioning.
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