As we learned in an earlier post, filters help keep the air we breathe cleaner. They block dust, mold and other allergens. However, there are many different types of filters and sometimes it can be confusing figuring out which one is just right for you.
Filters are graded by their percentage of ‘arrestance.’ Arrestance refers to the amount and size of particle they stop. The higher the percentage, the smaller the particle the filter will stop and the cleaner your air. In most duct systems, there are three main types of filter systems: Conventional “Throwaway” Fiberglass, H.E.P.A. and Electronic Air Cleaners.
Conventional “throw-away” fiberglass – these are the most common and inexpensive filters you can buy. You can see through these filters. They stop only 15% of the largest dust particles in the air and have no effect on smoke, pollen, micro-organisms, or other similar pollutants. These need to replaced on a monthly basis.
H.E.P.A., or Pleated Paper – these filters might be described as looking like a paper version of drapery pleats and they arrest up to 45% of the particles in the air. They can be found at most home improvement/hardware stores and come in the same size as a fiberglass filter. They should be replaced every 1 to 3 months.
Electronic (not electrostatic) – this is the best filter in terms of stopping particles. It uses ionizing cells. This filter has the highest capture rate of up to 95% of all airborne pollutants including mildew, dust, animal hair, lint, dust mites, fungus, smoke, cooking grease, mold and viruses. An electronic air filter can pay for itself by increasing energy efficiency and also prolonging the life of your HVAC system. By stopping all of the particles, they also reduce the need to dust furniture. In order to reap the maximum benefits, they must be removed and cleaned once a month in either your dishwasher or with a hose.
