Self Help

Kitchen exhaust fans, air conditioners, hot-air furnaces and other home equipment contain air filters, which trap dust particles and clear the air of smoke, pollen, atomized grease and other foreign matter. Filters in time become clogged, lose their effectiveness and may allow dust or grease to enter air ducts and coat air conditioner coils, putting strain on the motor with resulting extra energy costs, possible breakdown of the equipment and potential fire hazard.

Types of air filters include the disposable, which are easily replaced with packaged fiberglass or charcoal filters, the permanent, which are washable for continuous use, and the electronic, which are self-cleaning. Frequency of washing or replacement depends on amount of use (as with the air conditioner) and environmental factors such as a nearby airport or busy highway that produces considerable soot.

Here are more details:

1. Permanent. This type consists of a metal screening, a porous plastic sheeting, or a fiber pad. When removing the filter for washing, release any retainer clips to avoid tearing. Soak the filter for at least five minutes in hot water and detergent, flush under running water, rinse. It may be replaced while still damp.

2. Charcoal. Most consist of charcoal pellets in a cloth pad. If you have difficulty finding replacement filters, write to the manufacturer.

3. Disposable. Most are fiberglass in a cardboard frame. For replacement, use the same type and model number as the original filter for correct fit.

4. Electronic. You probably remember from school days that when a plastic rod is rubbed on a bit of cloth it becomes electrostatically charged and attracts bits of paper. This basic principle operates in an electronic air cleaner to extract particles in the air as small as one-millionth of an inch, including tobacco smoke.

In an electronic air filter, charging a filler of polystyrene foam causes it to attract and trap particles from air drawn over it by a fan. An aluminum screen retains the larger particles, and a layer of charcoal absorbs odors. Electrostatic filters can be installed into a forced-air heating system, or are available in individual cabinets. The screen and filter of these units are self-cleaning.

Filters are not to be confused with air fresheners, which come in various forms that function, essentially, by imparting a pleasant scent to overcome an unpleasant odor.