Ductwork Contamination & Indoor Air
How crawl space ductwork became a health issues in American homes.
Crawl space ductwork is one of the most overlooked contributors to indoor air quality problems. During the summer, ductwork is often the coldest surface under the home. When hot, humid air enters the crawl space, it condenses immediately on cold metal ducts and the insulation wrapped around them. That moisture soaks into the insulation and remains trapped for long periods of time.
Over years of exposure, duct insulation becomes heavy, moldy, and structurally compromised. Flexible ducts sag, twist, and collapse. Metal trunk lines begin to rust at seams. Rodents are attracted to damp insulation and often damage the duct system further. All of this occurs out of sight, which is why many homeowners are unaware their ductwork is failing.
Because all conditioned air passes through the duct system, contaminated ductwork directly affects the air inside the home. Odors become noticeable when the HVAC system runs. Rooms heat and cool unevenly due to restricted airflow. Energy bills increase as air leaks into the crawl space instead of reaching living areas.
Duct cleaning does not solve these issues when insulation is moldy or wet. Porous materials cannot be cleaned effectively. In these cases, repair or replacement is the only long-term solution. Protecting new ductwork requires controlling the crawl space environment. Without moisture control, even new ducts will fail again.
