Duct Leakage Testing
We perform several types of duct leakage testing in Indiana and Kentucky on residential heating and cooling systems. These tests are often required during new construction as part of the energy code compliance verification.
When new homes and other residential buildings are constructed in Kentucky and Indiana, they both should be built to the standards of their respective energy codes to comply with their building codes, which require duct leakage testing on certain types of 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.
Click here to download a list of what needs to be done before scheduling a duct-leakage test!
To test leakage to outside only, there are two methods. One method uses a "blower-door" system to simulate air-leakage on the house while the duct leakage test is being performed using a "duct-blaster", as shown in the video above.
The other way we can test duct leakage to outside is by doing a "subtraction method test" using a blower-door only. The video below explains this method.
The Kentucky energy code allows for up to 8 CFM of duct-leakage per 100 square feet of conditioned floor area served. 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).
Kentucky also requires a "Duct Test Verification Form" (DTV Form) to be completed by the company performing the test, which is given to the builder and code compliance officer for verification purposes.
The Indiana energy code only allows 4 CFM of duct leakage per 100 square feet of conditioned floor area. (Twice as stringent!)
In order for the duct-leakage 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 completion. Each additional system in the house that needs tested will also take another 30-45 minutes to setup and test, depending on the size of the house.
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.
Want to see a good example of how to seal ductwork properly? Check out the video below!
You can also download this form for detailed instructions on how to seal ductwork properly!