Keeping Your Air Conditioning Working All Summer Long

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Air Conditioning Filters 101

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Spring is here, so that means it's time to catch up on home maintenance chores. One of those tasks should include calling your heating, ventilation and air conditioning (HVAC) specialist and scheduling your annual air conditioner checkup so it's ready to go when those hot summer days get here. Here is what you need to know about your air conditioning unit's filter.

How Often Does an Air Conditioner Filter Need to Be Changed?

You should check your AC filter monthly to see if it needs to be replaced. It may not always look obvious that the filter needs to be changed, but generally, if it is working properly, it will actually look dirty, with a fine gray, dusty sediment on it. You can go as long as three months in between changing the filter, but keep in mind, the cleaner the filter, the more efficient your air conditioner will be.

If the filter doesn't appear dirty, check these things:

  • Does the filter fit snugly into the holder? If not, you have the wrong size.
  • Is the filter installed upside-down or backwards? Make sure you are sliding it into the holder the way the arrows indicate.

What Is MERV and What Number Is Best?

MERV stands for Minimum Efficiency Reporting Value. This is the rating system that is applied to air filters and it indicates how well the filter will do its job. The higher the number, the more particles the filter will remove from the air.

An air filter with a MERV 6 rating is suitable for homes that don't have pets and no one has any allergies, breathing, or sinus problems. MERV 6 filters will collect the largest particles in the air.

An air filter with a MERV 8 rating will catch mold spores and the debris from dust mites, common allergens.

An air filter with a MERV 11 rating is ideal if you smoke in your home or if you have pets. Cigarette smoke, dander, and hair from animals can be troublesome, and a MERV 11 filter is best for these households. An air filter with a MERV 13-16 rating are extremely efficient filters that can trap even bacteria and air-borne viruses. These filters are usually reserved for hospitals and surgical facilities, however. Because they have smaller pores, they also have more airflow resistance. This can make the air quality in a typical home go down. A filter with this high of a rating isn't suitable for handling the dust, smoke, and pets in residential situations.Stick to a MERV rating of 8 or 11 for most homes.