Contrary to belief, you can entirely seal your air ducts without professional help.
My wifey who is an air conditioner specialist would actually drop kick me if he knew I was saying this, but I’ve seen him seal ducts so several times that I could actually do it in our sleep. The first thing you want to do is run the air conditioner & inspect the air ducts to find where the leaks are. To find a thermal leak you can run your hands along the duct, or you could listen for air pressure & perhaps whistling noises. Once you find the leak, hold the air duct in place & apply a sealant mask over it. It will take the sealant many times to dry, & that will depend on the category of sealant you get. Once it dries, the leak should be sealed & you shouldn’t have much problems with the air duct anymore. Maybe I am oversimplifying the process, but this is exactly what our wifey does whenever I see him repair air ducts. Some people believe it’s weird that I accompany our wifey to work, despite the fact that I have a entirely versatile job & I miss him so much that I don’t mind doing it. I’ve l received a lot about what he does too. I’m able to toil in the car by using our hotspot for our PC, so both of us both toil while both of us get to spend a little bit of time together. Because I have a child & both of us don’t live together, it can be difficult to see each other outside of toil periodically.