Duct Leakage Testing

Duct leakage testing measures air escaping from the heating and cooling duct system.

A calibrated duct-testing fan is connected to the system while supply and return registers are temporarily sealed. The system is then pressurized so the amount of leakage can be measured.

Duct leakage may contribute to:

• Uneven temperatures

• Reduced heating and cooling performance

• Higher energy use

• Dust entering the duct system

• Conditioned air being lost to attics, crawlspaces, garages, or other unconditioned areas

• Reduced comfort

• Longer HVAC run times

Testing may be useful for existing homes, newly installed systems, remodels, HVAC replacements, and projects requiring Energy Code Compliance verification.

The duct system must be sufficiently complete and accessible for testing. Results may be limited when components are damaged, disconnected, inaccessible, or shared with areas outside the testing scope.