A duct blaster test combines a small fan and pressure gauge to pressurize a home’s duct system and accurately measure air leakage of the ductwork. This test is similar to a pressure test of a plumbing system and is performed at project completion. Duct leakage can increase heating and cooling costs over 30% and contribute to comfort, health and safety problems according to Southface Energy Institute.
When combined with a blower door test, the home can receive DET Verification (Duct & Envelop Tightness). DET Verification is required in Georgia to receive a Certificate of Occupancy on a newly constructed home or a home that has had significant renovation.
When a home has had either a duct blast test or blower door test performed, the results of the test are posted on the HVAC Air Exchange Box or the Electrical Box of the home. Ductwork for mechanical systems must pass a leakage to outside level of duct tightness of 8% of the floor area; e.g., a 1,000 square foot house could have up to 80 cfm of leakage in the ductwork.