Changing your HVAC system‘s air filter regularly is one of the most important things you can do to keep the system working right. But choosing the right air filter is also important, and if you’re like a lot of homeowners, you haven’t a clue which is best for your household or your HVAC system.

The right air filter can play a dual purpose: not only will it protect the system from dirt that builds up and makes it harder for the A/C or furnace to work efficiently, but a good quality filter can also improve the indoor air quality of your home.

Let’s have a look at what constitutes a good quality filter, and then you’ll have a better idea what to choose.

Not All Air Filters Are Alike

You’ve no doubt noticed when you buy air filters that some cost more than others. What’s the deal with these better quality filters, and are they really worth the extra cost?

If you’ve been using an inexpensive fiberglass filter, you should be aware that all it does is catch some of the larger particles that are drawn into your system’s air supply. These inexpensive types get dirty fast and should be checked at least once a month and changed when dirty.

Move down the aisle where filters are sold and you’ll see slightly more expensive types. These air filters are pleated and made of cotton fibers or polyester. They do a much better job of filtering smaller size particles, so they can catch some of the pollutants that may be difficult for your family members to breathe.

What Are Air Filter MERV Ratings?

The HVAC industry rates air filters by a metric known as the minimum efficiency reporting value, or MERV. The scale represents the filters’ ability to trap particles from 0.3 to 10 microns in size.

Here’s a rundown of what the various sizes of filters will do:

  • MERV 1-4: Filters intercept particles greater than 10 microns, including dust, pollen, dust mites, cockroach debris and carpet fibers.
  • MERV 5-8: Filters intercept particles from 10 to 3 microns, including mold, pet dander, spores and dust mites.
  • MERV 9-12: Filters capture lead dust, Legionella and other particles from 3 to 1 microns.
  • MERV 13-16: Filters intercept particles 1 to 0.3 microns, including bacteria, smoke and insect dust.
  • MERV 17-20: Filters trap viruses and other particles less than 0.3 microns. They are rarely used in homes. Instead they’re used in hospitals and research settings.

Filters rated higher than 12 aren’t good choices for the typical residential HVAC system, as they reduce airflow. Should someone in your home have allergies or a respiratory issue and need better filtration, ask your HVAC consultant about modifications to your system that will allow denser filtration.

Types of Air Filters

The better quality filters mentioned above are mostly made of very dense layers of material and are pleated to provide more material for filtration. But there are other very effective types of air filters you may want to try:

  • Gas phase activated carbon filters: These remove tobacco smoke and other vapors from the air.
  • Electrostatic filters: Electrostatic filters stop particles by means of static electricity generated in the material of the filter as the air is drawn through it. These can be disposable or permanent, though the latter requiring washing. The washable filters last for several years.
  • Electronic filters: These rely on a transformer to provide a negative electronic charge, which traps the dust particles as they pass through. These filters usually have a collection plate or other grounded surface. The plates or surfaces must be cleaned regularly to be effective. These filters are expensive, but they do a good job removing particles.

Change the Air Filter Frequently

Whatever type of air filter you choose, remember to check it frequently and change it when it’s dirty. Dirty air filters not only cause your system to work harder, but they also cost you more to operate the HVAC system, as well as increase your carbon footprint by forcing the system to use more energy.

For more information on choosing the right air filter for your home, contact Roberts Air Conditioning. We guarantee satisfaction to our Gulf Shores customers.