Some homeowners opt to take on duct sealing as a DIY project. To start, seal air leaks with putty or metal tape and insulate any ducts that are accessible, such as those in attics, tight spaces, unfinished basements, and garages. Never use adhesive tape, as it won't last long. Sealing ducts from the inside out is a much more complicated process and will likely require hiring a professional.
Essentially, what they will do is spray the inside of the duct with a liquid rubber sealant. They will then pressurize the duct system with a fan and use a computer to analyze the data and determine the amount of air being filtered through the ducts. In a duct system, the main line is usually made of metal or fiberglass rather than flexible ducts. If there is a gap on the side of one of these lines, repairing it can be as simple as applying adhesive tape to seal the hole.
Most homeowners don't consider sealing their home's air ducts, but it's an important step in maintaining energy efficiency. Either way, having your ducts properly sealed will help you balance your home's air temperature and improve air quality. For the most daring DIYers, these are the basic principles of duct sealing and gap repair techniques used in most modern systems.
