Not something we talk about at parties, but the fact is leaky ducts are a common problem and a major source of energy loss in a lot of homes. Homeowners pay dearly to heat and cool their homes. The air traveling through their home’s forced air delivery system is sometimes partially lost by way of loose connections in the ductwork system. Unfortunately in many homes a significant amount of that air may escape through duct leaks before it ever reaches the living space.
Finding duct air leaks and then fixing them (as opposed to replacing every duct run in your home) has been an ongoing challenge for the HVAC industry. First, you can’t fix a leak if you can’t see it, and even if you can, slapping some duct tape on has proved an imperfect and temporary solution. Never use duct tape on ducts; a UL 101 metalic or similiar tape is always preferred. Even small holes when added up throughout the system can account for a huge loss of efficiency. The EPA estimates that 10-15% of air volume is lost as it travels through leaky ducts, in homes and in commercial/industrial buildings.
Here’s a good video regarding the correct sealing process of ducts: