As long as ductwork has carried heated or cooled air to a space, there have been problems with air leakage. However, with energy prices spiraling upward, more focus is being paid to this industry-wide problem — especially since some estimate that residential and commercial duct leakage costs consumers about $5 billion a year. In addition, it is estimated that a typical house with ducts located in the attic or crawl space wastes about 20% of heating-cooling energy through duct leaks and draws approximately 1 kW more electricity during peak cooling periods.
In a 1998 study at Lawrence Berkeley National Laboratory (LBNL), researchers determined that duct tape is one of the main reasons why ducts leak. And duct tape is often used to seal ductwork connections.