If you breathe while inside your home, air quality should be a priority. Indoor Air Quality (IAQ) may be affected by these four key problems with ducts systems: 1) Leaky ducts. Bad air, mold, and odors can easily make its way through your entire home if return ducts are disconnected or poorly filtered. 2) Unbalanced duct leakage. Negative air pressure resulting from supply-side duct leakage increases infiltration of bad air outside the home. 3) Backdrafting due leakage. Negative pressure may lead to hazardous backdrafting of comubstion appliances. 4) Leaky ducts lead to mold. Reduced moisture control means the spread of mold spores and dangerous air quality.
Read the full article here: Four Ways Bad Duct Systems Can Lead to Poor Indoor Air Quality | GreenBuildingAdvisor.com