Does Air Conditioning Improve Indoor Air Quality?

On those beautiful spring and fall days, when it takes every bit of self-control not to throw the windows open and run away from work just to bask in the sunshine, we’re often reminded of just how stale our indoor air can become from a summer or winter of keeping our homes shut.  These times of year, so many people wonder if keeping their homes closed is really the best thing for indoor air quality, but experts say that air conditioning, when properly maintained, can improve indoor air quality significantly.

How Air Conditioners Help

Air conditioners are designed to take the air in your home, suck it through a filter, pass it over a very cold coil and push it back out through a series of vents.  Easy enough.  But during that process, your air conditioner and air handler are actually removing a great number of particles from the air and making your home a safer place to breathe.  The larger particles are caught by the filter before the indoor air even enters the air handler. Then the air handler pulls the water soluble particles out of the air, along with excess moisture.

Cycle after cycle, dust, debris and pollutants are brought into the system through the return air duct, where the air is cleaned and returned to the room.  If your air still feels stuffy, stale, or you’re still struggling to breathe, you may need to take a better look at the whole system.  There are several ways you can help improve your air conditioner’s ability to filter the air, including:

Changing the Filters Often.  It may sound overly simplistic, but the cleaner your filters are, the cleaner your air will be.  Check your filters at least once every two weeks and replace them as soon as they look dirty.  You may have heard that impacted dirt on your filter helps catch more dirt — but what this actually does is reduce air flow, making it harder for your air conditioner to clean the air.

Cleaning the Evaporator Coil.  Some furnaces are set up so that you can clean your evaporator coil yourself, while others will  require an air conditioning technician for the task. Either way, keeping a coil clean is vital to having clean indoor air.  Get your evaporator coil cleaned at least once a year and check it (if you can) every time you change the filter.

Tightening and Cleaning Ducts.  Ducts that are dirty simply blow more dirt into your home — the same goes for ducts that are open to the attic or crawlspace.  Ensuring that your ducts are tightly sealed and having them professionally cleaned eliminates a potentially endless source of dirt, dust and pollutants.

Choosing Air Conditioner Filters

If you’re trying to improve your indoor air quality with your air conditioning system, you also need to pay special attention to your air conditioner’s Minimum Efficiency Reporting Value (also known as the MERV rating).  As long as your system is rated to handle the filter you choose, you can target the pollutants that are really bothering you by choosing a filter woven tightly enough to capture the offenders.

Typical home filters have a rating of MERV 8 to MERV 13, though MERV ratings from 1 to 20 are often available for commercial customers.  These numbers mean the same thing no matter if you’re using a disposable filter or a washable electrostatic filter.  Here’s a quick rundown:

MERV 8.  MERV 8 is considered a “better” residential filter by most retailers.  These filters can catch mold spores, dust mites, animal dander and other fine particles like hairspray.  MERV 8 rated filters can remove up to 35 percent of all the dust particles in the air; they rate in the 90th percentile or above for dust removal when compared to other filters.

MERV 9  through 12.  With the ability to capture airborne particles as small as milled flour and automotive emissions, filters with MERV ratings of 9 through 12 are very good filters for improving air quality.  MERV 9 filters remove up to 45 percent of dust particles from the air; MERV 12 filters can remove as much as 75 percent.  Bigger isn’t always better, though — sometimes these filters create unnecessary stress on your air handler.

MERV 13.  If you have immune system problems, a MERV 13 filter may be for you — they can trap all types of bacteria, tobacco smoke and even sneeze droplets.  You can expect a filter in this category to catch up to 90 percent of the dust in the air, but have a pro check your unit to be sure it can handle the reduced air flow these filters can create.

Although an air filtration system will handle considerably more air cleaning than your air conditioner alone, if you simply want to improve your indoor air quality, all it takes is a little extra effort to keep dust out of your system, and changing your filters can make a big difference.  If your unit’s blowing more dust than it’s collecting, give the professionals at Precision Air a call at 1-602-349-6922.  We’ll clean your whole system on your schedule and improve your indoor air quality in no time flat.


Precision Air & Plumbing October 31, 2017


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