How to Clean Permanent Furnace Filters

Permanent furnace filters are convenient and often economical. They come with impressive names like "electronic" and "electrostatic" and promise high "MERV" values. It's quite likely your permanent filter is slightly more efficient than the disposable ones, but it has nowhere near the efficiency of the HEPA filters they use in hospitals and bars where smoking is allowed. The most important aspect of permanent filters is that they must be cleaned in order to perform properly or they won't be efficient or economical.

Things You'll Need

• Vacuum cleaner with attachments Vinegar Dish soap Garden hose or sink sprayer Bottle brush and soft cloth

Instructions

1. Read the directions to find out what type of permanent filter you have. Find out whether you've got the type with a pleated filter or one with polyester or metal insides. The ones with the pleated insides are either refillable or permanent. The filters with metal grills and polyester or metal insides are generally cleanable. Whatever type filter you have, it must be kept clean for the furnace and air conditioner to work efficiently. A filter that is too clogged with dirt can actually damage the fan motor on the furnace because the dirt-thickened filter causes the motor to strain as it pulls air in.

2. 

   Find out whether your "electronic" filter uses electricity or static electricity to attract dust. H. igh-efficiency filters can remove as much as 90 percent of common household airborne debris and need special cleaning. If you have questions about a permanent filter that you've inherited from a previous owner, visit your local hardware or home store or call the heating specialist who installs or services your furnace. They generally leave a sticker on units whenever they service them. One of these people will know what kind of cleaning is recommended for your filter.

3. 

   Vacuum polyester and electronic permanent filters to remove dust. If you're fortunate enough to have an attachment for pleated blinds, these fit perfectly in pleated filters. Use the small brush attachment for metal parts on electronic filters. Vacuuming these filters helps fabric parts keep their shape and keeps electronic parts dry. Clean these filters every month or two during heavy-use heating or cooling seasons and no less frequently than every three months otherwise.

4. 

   Wash metal screens and parts of non-electric electrostatic or metal-weave filters with a sink sprayer or garden hose. Use a mild solution of dishwashing detergent and soft brush if the dust is dirty or greasy, such as what might occur when a filter is near a kitchen or workshop. Let the filter air-dry completely before replacing in the furnace sleeve. If there are "nooks and crannies," use a hair dryer to get them dry because some filters do not use rust-resistant metals or coat-soldered joints. Clean these filters every month during high-usage periods and every two months at most.

5. 

   Clean blade-type electrostatic filters with a soft, lint-free cloth. Dampen the cloth with vinegar to soften greasy dirt but never soak a blade that's part of a filter that uses electricity. Never spray these filters or their housing with household cleaners--that can damage surfaces and the spray can carry water into electronics. Clean these blades once or twice a month, depending on the size of the filter.

Resources

• Allergy Buyers Club filter descriptions
• Furnace filter reviews and information