Duct Leakage Testing

Duct blaster connected to a central return

When new homes and other residential buildings are constructed in Kentucky and Indiana, they both should be built to the standards of the 2009 IECC for energy code compliance, which requires duct leakage testing on certain homes built.  Both states require duct leakage testing if there are any ducts located in attics, garages, or unconditioned crawlspaces.  The codes require a pressure test be performed with all supply and return duct openings sealed and the duct system pressurized to 25 Pascals of pressure.  

To test leakage to outside only, a "blower-door" system is used to simulate air-leakage on the house while the duct leakage test is being performed.  The code allows for up to 8 CFM of duct-leakage per 100 square feet of conditioned area served.  So for example, a 2,000 Sq Ft one-story patio home built on a slab foundation could have duct leakage up to 160 CFM (2,000/100 = 20 x 8 = 160).

Blower door set up in front doorIn order for the duct-blaster test to be conducted, all windows, doors, and attic hatches should be closed and locked, and all weather-stripping should be installed.  The supply and return ducts should have their registers and grilles installed as well.  This is important, as we must seal the openings, and without the grilles and registers in place, it can be very difficult to do so.

The test typically takes about an hour to perform from setup to packup.  Each additional system in the house that needs tested will also take another 30-45 minutes to setup and test.  Please note that the actual pressure test only takes a few minutes, so other people and tradesmen can still enter and exit for the majority of the time we're on site.