Air Purifier Filter Maintenance

Air quality control

Air purifiers, when installed and operated correctly, can greatly benefit the health of the members of a household and contribute to a pleasing indoor environment.  Air purifier units vary greatly in terms of shape, price, and technology, but also in the amount of maintenance and cleaning they require.  Even "maintenance-free" air purifier systems, those promoted as self-cleaning, should be checked out periodically.

Measuring up

Choosing the correct air purifier is a critical first step in getting better air.  The size of the job an air purifier can handle can be determined using two factors:  the size of microscopic particles that it can take out of the air, and the volume of air it can process. Particles are measured in microns (a micron is one millionth of a meter).  Grains of pollen measure from around 10 microns, while dust particles run 0.5 to 50 microns. 

The smaller the particle, the more easily it may enter deep into the lungs and compromise the respiratory system. Larger particles have a harder time getting as far into the lungs, but can still cause allergies and asthma.  The most advanced filtration systems can remove particles .3 microns in size.

The EPA and the American Lung Association have created the CADR measurement, or "clean air delivery rate," as the prevailing standard of air purifier efficacy. This measurement takes into account the volume of air cleaned within a certain time: the higher the CADR, the more effective the filter.  When shopping, look for the Association of Home Appliance Manufacturers' (AHAM) seal of approval. The seal will list three CADR numbers: one for tobacco smoke, one for pollen, and one for dust.

How do I clean my air purifier filter?

Beyond spring cleaning

Proper installation, operation, and maintenance are critical for effective operation of any air purification system:

To maintain filter efficiency, a filter must not allow any air to pass through its settings or seals.  A filter assembly must be set flush against its casing and be free of obstructions.  Take a look at the filtering mechanism periodically to make sure it has not come loose.  Follow the manufacturer's diagrams and instructions closely; an improperly installed filter is useless.

Check the filter for dust and debris buildup frequently, no less than once per month during peak use.  Follow the manufacturer's recommendations regarding replacement and cleaning, but check visually to see that the filter's surface remains free of large particles and accumulation of dust.  A clogged up filter can actually provide a breeding ground for disease.  Washable filters save money over time, but must be kept clean to function.  Disposable filters can be convenient, but once they have passed their expiration date, they must be discarded.

A pressure gage can help to determine when a filter has become too clogged to function correctly; some air filters include sensors to monitor performance and indicate when a filter must be replaced.

More information on air purifiers