Why Some Air Filters Are Better Than Others

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Why Some Air Filters Are Better Than Others

Clean and efficient air filters are beneficial in many ways. First, clogged or dirty air filters can cause your heating and cooling system to function improperly, leading to possible system damage and/or replacement. Maybe more importantly, air filters can also help maintain good indoor air quality (IAQ) in your home, which is a key component to good health. Those are two great reasons to perform regular air filter maintenance on your HVAC system.

The good news is, when it comes to do-it-yourself HVAC maintenance, it doesn’t get any simpler than air filter maintenance. Air filters should be cleaned or replaced regularly. In the meantime, a good way to test if your air filter is effectively removing airborne pollutants and allergens from your home is to perform this easy test. Lay your current air filter flat, then pour common table salt though the filter. If some or all of the salt passes through to the other side, this is a telltale sign that your filter will not probably not slow down dust particles or pollutants of similar size. If that is the case it is time to replace the filter and perhaps upgrade to a more efficient one.

So, what types of filters are best at enhancing IAQ? The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) uses a rating scale called the minimum efficiency reporting value (MERV). MERV ratings range from a low of 1 to a high of 20 and is based on the following: the air filter’s proficiency at removing particles and resisting airflow and the filter’s projected life expectancy.

Here are three common types of air filters and their MERV ratings:

  • Flat-panel fiberglass. These inexpensive and disposable filters, which are composed of layers of fiberglass fibers, are rated 1 to 4. They come with a medium efficiency rating for collecting larger airborne particles but a low rating for capturing smaller airborne pollutants.
  • Pleated polyester. These filters have a rating of 5 to 13, primarily because the pleats create more filter surface area to capture smaller air particles and pollutants. They are generally more expensive than fiberglass but have a longer life expectancy
  • High-efficiency particulate air (HEPA). The best air filter in regards to IAQ. Recognized by the Occupational Safety and Health Administration as the top filter for removing air particles and pollutants, HEPA filters are rated from 17 to 20. However, as most residential heating and cooling systems are not built to operate with HEPA filters, switching to one means hiring an HVAC professional to retrofit your furnace.

In the meantime, remember to regularly check, clean and replace your old filter. Your home’s heating a cooling system will thank you for it and your family will appreciate the good IAQ! For more air filter efficiency information or for a fall tune-up, call your friends at Kotz today.