The test and balance can be performed at any time, but the best opportunity is near the end of construction. This would be after all HVAC systems have been installed and started but before turnover to operations. During this time period, the TAB firm may uncover deficiencies that can still be corrected by the contractors before they leave the site and before the deficiencies create problems for your operations staff. Melink typically schedules a TAB one to two weeks prior to a facility's opening.
The building should also be rebalanced in whole or in part whenever the building is remodeled, when any HVAC equipment is replaced or modified, and if any air balance-related issues are observed.