Testing for air leaks can bring savings

November 3, 2009

Performance testing is a way to test the efficiency of the components of a house, including its ductwork, the building envelope and a home’s heat pump system. It does not address insulations levels, however, which are also important to evaluate. In the Northwest, the testing standard adopted by Bonneville Power Administration and Clark Public Utilities is Performance Tested Comfort Systems, or PCTS.

"PCTS is a guarantee that the technician is trained in using sophisticated testing equipment," said DuWayne Dunham, an energy counselor at Clark Public Utilities. "In fact, our incentive programs specify using PTCS testing of heat pumps and duct sealing."

The three specific PTCS tests are blower door, ducts and heat pump commissioning. Here is a rundown on each one:

• PTCS blower door: This test determines air leakage rates of the entire house by first depressurizing the home using a large fan motor. The technician identifies air leaks around doors, windows, plumbing and where cable TV and electrical service enters. Sometimes the amount of leakage is surprising. Plugging air leaks can reduce heating costs by up to 20 percent, according to the Alliance to Save Energy.

"I’ve seen older homes that leaked as much air as having a three-foot window open three inches," said Mike Deloria, a home energy analyst with Area Heating in Vancouver. "That’s how much heated air was being wasted, going out of the house."

• PTCS ducts: Duct blasting determines the air leakage in a home’s ducting. Up to 40 percent of the homes in the Northwest have duct leakage rates of 15 percent to 30 percent, according to the Northwest Energy Efficiency Alliance. "If you’re leaking heated air into an attic or crawl space, you’re paying a lot more for heat than you need to," Deloria said. "We identify the leaks and then seal them."

• PTCS heat pump commissioning: This test makes sure the home’s heat pump is working to its promised efficiency and is sized and installed properly. It doesn’t matter how old the heating system is either. "Just because someone before put in a new system, you don’t know how they did it," Deloria said.

In his six years of field testing, Deloria estimated only 10 percent of houses three years old and newer had heating systems that passed on the first test. "The ducting systems were even fewer," he said.

A home performance test by a certified PTCS technician costs between $200 and $300. But by knowing where your home is wasting energy, you can correct the situation and begin recouping the cost in lower heating and cooling bills.