





Ten Steps to Preparing Systems for TAB
To avoid problems, delays, cost overruns and conflicts due to issues identified during TAB (testing, adjusting and balancing, also known as air and water balancing), mechanical contractors and/or construction managers must put procedures in place that ensure systems are fully ready to undergo the TAB process.
The Problem
On almost all new construction and renovation projects, similarly experienced AABC- or NEBB-certified TAB contractors bid against one another, and the contract is generally awarded to the lowest bidder. This means the balancer’s margins are tight, so when problems are identified – and they always are – the TAB contractor has very limited time for troubleshooting and making the necessary adjustments to balance systems to within +/- 10% of design specification. Therefore, multiple problems are usually kicked back to the mechanical contractor or construction manager, usually on an ongoing list. This results in change orders, increased project costs, and unnecessary back-charges to the mechanical contractor. The schedule may be extended, missing critical Certificate of Occupancy dates. Rampant finger-pointing ensues, and there are hard feelings all around.
The Solution
Here is a list of ten things mechanical contractors and construction managers can do to prevent costly, schedule-busting issues during testing, adjusting and balancing. Verify that:
- All air systems are running properly and continuously without tripping or going into alarm. Verify BMS system is communicating and controlling.
- All manual dampers, fire smoke dampers, and control dampers are open to allow full flow.
- All flex duct is taut, kept to minimum lengths, and not kinked or crushed.
- All diffusers are installed properly, with no restrictions.
- AHU static pressure and flow matches design intent.
- All filters are installed.
- VFDs are operating at the proper frequency with spare capacity for filter loading.
- All supply, return and exhaust have proof of airflow with no major pressure drops or restrictions.
- Verify basic HVAC sequence of operation with the BMS system along with temperature and humidity control.
- Walk the HVAC systems down with the balancer to ensure everything is ready for TAB.
About MSC - The Go ToGuys
We are a service sub-specialist in the technical intricacies of HVAC, process cooling, and building automation systems in commercial, industrial, and institutional environments. MSC is recognized as the leading industry expert in solving elusive problems and attaining peak performance from clients & mechanical equipment and overall systems.
Located in northern New Jersey, MSC is the only specialized contractor of our kind in the Northeast and Mid-Atlantic regions. We are MSCA STAR-qualified, NEBB-certified, fully-licensed in electrical, plumbing and HVAC, and our engineers and technicians are the most knowledgeable in our field.
MSC - Mechanical Service Corp.
41 South Jefferson Road
Whippany, NJ 07981
973-884-5000