top of page


These tests measure how much conditioned air is leaking from your entire HVAC system - from the return grill to the supply registers in your ceiling.  Expensive conditioned air leaking into the attic is pure waste.


Total Duct Leakage

This test measures all the air leaking from your HVAC system - even if some of that air is leaking into your rooms.

It's the most common duct test, even though it has nothing to do with energy efficiency.

In fact, total duct leakage is not even included in energy modeling calculations.


Duct Leakage Outside Conditioned Space

This test measures how much conditioned air leaks to places you don't live - especially to attics.

This is the leakage that matters and it has a big impact on energy efficiency.

The test can be performed to determine if air sealing is needed.  Performed again after sealing is done measures the effectiveness of the work. 

bottom of page