A question we often get this time of year when customers are replacing their house air filters before turning on their air conditioners is “is there a difference between the options of air filters?” Most definitely. And not just in the price of the filter. The basic fiberglass filter has the lowest filtering rate – around 50. The best filter on the market has a filtering of 2200. But what do these numbers really mean to the consumer? The filter rating represents the effectiveness of a filter at capturing the smallest airborne particles. 99% of most airborne particles are smaller than one micron. For reference, smoke is made up of particles less than 1 micron. So for the less expensive filters, airborne particles are difficult to capture. Electrostatic, pleated filters are the most effective when new and clean. Basic fiberglass furnace filters cost between $2-4 but they don't do that good a filtering job – it’s filtering rate is 55. You can pour some granulated sugar through the filter, as this picture shows, which is much larger than most of the airborne particles found in homes & offices. Imagine what dust, pet dander, pollen and other small particles can flow right through this type of filter.
In contrast, slightly more expensive filters are good-quality, pleated, electrostatic filter and it has a filtering rate of 1000, and costs between $16-25. This type of filter can handle pollen, mold spores, pet dander, household dust, even smog and smoke. Higher-rated filters can even handle bacteria and particles that can carry viruses.
No matter what type of filter you decided upon, make sure you install it properly. All filters have an arrow on them to mark the direction for the air flow. Also, replace fiberglass filters every month. Pleated filters should be replaced at least every 3 months. Inspect your filters regularly. Once the filter gets dusty, replace it right away. A dirty air filter that costs $16 could lead to a very expensive repair of your heating or air conditioning system.
