Posts Tagged ‘TAB’

Balanced Air Distribution

Tuesday, October 27th, 2009

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You’ll Know If It’s Not Balanced

One room runs too cold, another too warm, while another seems to have a stale odor to it. Assuming adequate air conditioning capacity and correctly selected and installed air ducting and grills, the obvious clue to disparate temperatures is unbalanced air distribution.

Air Balance Mechanisms

 ManualHandQuadrantBalancingDamperManually-adjustable dampers either at the grills or upstream in the air ducting control air flow so as to equalize air distribution throughout a zone of control. In the case of a single-zone system that supplies conditioned air to multiple rooms, air balance is critical to even comfort. The test and balance (TAB) technician uses a flow hood instrument to measure discharge air flow. The TAB technician sets air flow at all grills according to a preset TAB schedule prepared by the system designer. Grills with integral dampers are a less costlyAdjustableResidentialGrill solution than manual hand quadrants in the duct, but the latter will generate less noise and it is located as close to the air handling unit as possible.

In the case of a variable-air-volume (VAV) air distribution network, motor-operated modulating dampers inherently balance comfort to match set points of the several zones. To learn more about ModulatingDamper-1VAV, click here.