An article I study said that the average residential ductwork allows up to 30% of heated and cooled air to leak out.
The majority of ducts are imofficially designed and installed, including lots of sharp bends that restrict airflow through the system.
They are not sealed tightly at the seams, creating gaps that sacrifice a good deal of conditioned air, then over time, small holes can develop that not only give up heated and cooled air but pull in air, fumes and other contaminants from unconditioned spaces. Spending extra to purchase a high-efficiency heater, heat pump or A/C is rather pointless if the ductwork compromises performance, however until coming across that article, it had never occurred to me to have the ductworks professionally maintained. I am quite conscientious about replacing air filters every couple of months and scheduling service in the Springtime and fall. I researched to find an Heating, Ventilation plus A/C contractor that offers duct testing, cleaning and sealing in my area. There was one that is certified to provide Aeroseal duct sealing, which is an innovative process that targets imperfections from inside the pipes. Because the ductwork is often hard-to-reach, it’s advantageous to utilize the Aeroseal process. The contractor first maintained airflow through the duct system and verified that approximately 20% of conditioned air was escaping, but he then plugged off all supply and return vents and pumped pressurized air into the pipes. The air contained sticky polymer particles. As the air leaked from numerous flaws these sticky particles adhered to the edges and gradually created a tight seal. I right away noticed an improvement in the comfort, efficiency and air quality of the home.