The ducts in your home are like to the “lungs” of the house. They conduct warm or cool air throughout your home. Most people ignore the health of their ducts until something goes haywire; you suddenly see debris in the air or it seems to take forever for the heated/cooled air to reach you.
Maybe it’s time for a duct inspection. Your ductwork may have developed a leak that needs to be sealed. Duct sealing is used when there is a small tear in the ductwork. Even if the leak is small, it can effect up to 30% of your heat or cool output!
You should hire a licensed HVAC technician to inspect your ductwork properly. They have the necessary equipment that can test and locate any issue without causing any problems.
If they discover a leak, and depending on its size, they will plug the leak with a substance called mastic. Mastic is a malleable putty that can be molded over the leak on the outside, to create a tight seal over it. The mastic will dry and harden. It is able to “move” somewhat and flex with the ductwork to a certain point. The technician may choose to cover it with a regulation metallic duct tape. This duct tape is not the same as the store bought type most people have on hand.
Duct sealant can last a very long time, sometimes up to 10 years; but it is prudent to have your ductwork inspected about once a year, especially if there are patches on the ducts.