Attempting to seal air ducts without the right training and equipment can lead to ineffective sealing and leave leaks untreated. Homemade sealants may not adhere properly or contain hazardous chemicals that can degrade indoor air quality when heated. There are still questions about the safety, effectiveness, and overall convenience of sealants, such as the potential toxicity of these products under normal conditions of use or if they catch fire. Trunk, branched, and radial supply duct configurations are the most suitable for ducting located in conditioned spaces.
Duct cleaning is often a scam, but sealing the ducts is beneficial in terms of efficiency. Sealing the air vents while ignoring the other air spaces in your house is like leaving most of the windows open and then wondering why wasps keep flying into your house. This is because the fan accelerates due to the higher static pressures generated by sealing an undersized duct system. Sealing ducts works great in a properly sized duct system. The amount of airflow a variable speed fan typically stays the same when a restricted or undersized duct system is sealed.
Multiple applications may be needed to seal the holes, as the sealant will only seal very small gaps and you'll have to form layers. Sealing the air throughout the house is so important for overall energy efficiency and comfort. Ducts that filter hot air into unheated spaces can add hundreds of dollars a year to your heating and cooling bills, but you can reduce that loss by sealing and insulating the ducts. The expulsion of condensate from the evaporator coil is another problem that occurs when an undersized duct system is sealed and a variable speed fan is used. If you're like most American homeowners, your recycle bin is filled with advertisements for various duct repair and sealing services. However, it's important to remember that without proper training and equipment, trying to seal air ducts on your own can result in ineffective sealing and leave leaks untreated.
In addition, homemade sealants may not adhere properly or contain harmful chemicals that can degrade indoor air quality when heated.
