For the past couple of years, I have been advocating the need to elevate the role of the TAB subcontractor to mechanical contractor to third-party responsibilities, and I can say firsthand that we are making progress with this important quest. Why is this significant? Think about a new automobile that has all of its systems commissioned (ignition, electronics, audio, electric door, and window package systems, etc.), but no one has tuned up the engine. Instead of 26 mpg, your new car is getting 17 mpg. This is similar to a building being commissioned except for incomplete air and water balancing. Sure, you get flow, but do you get the most efficient flow and operation at the right pressures?


Adding value

Back in 1994, I took the National Environmental Balancing Bureau (NEBB) test. It was approximately a six-hour written test followed by four-hour field test. When I took the field test, the first thing I did was sit down and sketch out a system flow diagram and documented the pertinent data (flows, velocities, and pressures) that I anticipated prior to picking up the tools and taking the readings. When I finished doing the flow diagram, the instructor - and this is the important part - said to me, “If you had not started with a flow diagram, you would have failed the test because you don’t start by picking up the tools and taking readings.”

I have never forgotten that comment, and yet, I don’t usually see a TAB technician create a system flow diagram unless I mandate this requirement, which I do every time we participate in the TAB firm selection.
So what is different so that now I can say, “We’re making progress?” Our insistence on specifying the following:
  • The TAB firm shall obtain the associated shop drawings required to determine design-to-actual operating data (coil pressure drops, fan curves, etc.) during the shop drawing submittal phase.
  • The TAB firm shall submit system flow diagrams with pertinent data (flow, pressure, velocity design) for each system to be balanced (list these systems in the specification) during the shop drawing submittal phase.
  • The TAB firm shall submit its proposed final report table of contents as part of the shop drawing submittal and include available information at time of submittal (certification number, technician resumes, observation checklists to be used, etc.).
  • The TAB firm shall attend and participate in “X” (state a specific number) field coordination drawing phase meetings, contributing air and water balancing requirements to the field coordination documents.
  • The TAB firm shall make “X” site visits to assess system readiness and submit its field report, digital photograph documentation, and observation checklists.
  • The TAB firm shall submit the final TAB report and also submit laminated system design-to-actual system flow diagrams to be mounted at the prime piece of equipment.
It is important to note that air and water balancing usually costs somewhere around $0.30 to $0.50/sq ft and the cost is already in the construction budget (unlike commissioning services that are frequently an added cost to the job). Based on the enhanced scope of work we are asking the TAB firm to do, the air and water balancing cost will now probably increase to $0.50 to $0.80/sq ft. So for $0.20 to $0.30/sq ft more on a project that will probably cost $250/sq ft, it is money well spent. Would you tolerate your automobile wasting your hard-earned money when a simple tune-up will improve performance?



The case for third-party

TAB work needs to be elevated to third-party responsibility to ensure the building gets its proper tune-up. I will go so far as to say that third-party TAB should be a prerequisite, just as commissioning is for LEED® projects.

But, we need to also make sure the TAB firms are on-board with this added work requirement. Interestingly, when we are successful at getting third-party TAB services on the project, it is a real challenge to get the TAB firm to buy into our concept. When I pull out the NEBB or AABC (Association Of Air Balancing Council) book and highlight the reference to completing the system flow diagrams, I am met with resistance from the TAB firm. We eventually get through this dilemma because this third-party concept is a culture change to the TAB firms.

If you want a copy of our sample third-party TAB Request for Proposal, go to the “Sustainable & Attainable” blog, download it, and then start demanding the TAB be third-party.