|Duct leakage accounts for much of the inefficiency of residential forced
air heating and cooling systems--the leakage of hot or cold air through
ducts that means a waste of your energy dollars. Most duct leakage could
be prevented with proper duct sealing. But field examinations of ducts
often find their seals failing over time. To provide lab data about which
sealants and tapes last, and which are likely to fail, we are conducting
ongoing accelerated testing at Lawrence Berkeley National Laboratory Environmental
Energy Technologies Division.
Our major conclusion so far is that you should use anything but duct tape to seal ducts. (We've defined duct tape as any fabric-based tape with rubber adhesive.) The testing we've done so far shows that under challenging but realistic conditions, duct tapes fail.
A report of of our research in Home Energy magazine provides more information on the longevity and failure rates of various duct sealing methods.
|What are the alternatives to duct tape for sealing ducts? All the other tapes we tested that claimed to be useful on ducts passed our test. Tapes require a clean, smooth, dry set of surfaces to hold well. However, in most do-it- yourself installations, it can be difficult to find good conditions for use of tapes. Non-tape sealant approaches such as the use of mastics may perform better.|
|A cutting-edge technique for sealing ducts is the aerosol sealant technology that was first developed at Lawrence Berkeley National Lab (see http://epb.lbl.gov/aerosol/index.html). Aeroseal Inc. of Austin, Texas is working to commercialize this technology.|