Preventing Dust From Forced-Air Heating and Cooling Systems
Richard Trethewey gives advice on maintaining a forced-air heating system to control dust
My mom's home always seems very dusty, yet the filters on her forced-air heating-and-cooling system never seem to get dirty. The air returns are working fine, pulling in enough air to hold a piece of paper in place. What's going on? — Anthony Ayelo, West Caldwell, N.J.
I can't tell you exactly, but I know which suspects to round up: the filter and the ducts.
If your mom is using the inexpensive, disposable spun-fiberglass filters, which trap only the biggest chunks of dust, then almost nothing is being done to clean indoor air. Replace them with pleated filters rated for the blower capacity of your system and you'll put a big dent in the problem. Just make sure to change them when they get dirty.
You probably also have leaky ducts, which let heated or cooled air escape and draw dirty air into the system. According to one estimate, about 20 percent of the air that goes through a typical forced-air system is lost through holes or gaps around fittings or unsealed joints between duct sections. Have a heating contractor pressure-test your system to determine what your losses are. If more than 2 percent of the air is leaking out, it's worth sealing every accessible joint with HVAC mastic or foil tape. Don't use duct tape, which eventually dries out and fails. When duct runs aren't accessible, a company such as can seal ducts from the inside with an aerosol spray.
— - saboteamos.info plumbing and heating contractor Richard Trethewey