Duct Leakage: How Much

January/February 2001
This article originally appeared in the January/February 2001 issue of Home Energy Magazine.
Click here to read more articles about HVAC
January 01, 2001
Q:Is there a standard for energy-efficient ducts? I was called to a home built in 1955 that is under a warranty from a recent sale. The customer wanted us to “fix the ducts.” I didn’t see anything wrong with the ducts, but they claimed PG&E (the local utility) tested them and they were too leaky. Is there a standard and how do you test for it? A: There are a number of state and federal standards that limit duct leakage based on different leakage test results. In the most common test, the registers are temporarily sealed and a fan is used to pressurize the ducts and measure the leaks.         To understand the test differences, you should know these duct leakage terms:         Total duct leakage. This refers to all the air that escapes from the duct other than through registers. A total duct leakage test measures all leaks, whether the air ends up inside or outside the house. This is the simplest and most widely used leakage measurement.         Leakage at 25 Pascals (Pa). When the ducts are tested, ...

To read complete online articles, you need to sign up for an Online Subscription.

Once an order has been placed there is an automatic $10 processing fee that will be deducted with any cancellation.

The Home Energy Online articles are for personal use only and may not be printed for distribution. For permission to reprint, please send an e-mail to

Email Newsletter

Home Energy E-Newsletter

Sign up for our free monthly

Harness the power of

Get the Home Energy