4 Ways Your Air Conditioner Impacts Indoor Air Quality

Most people are aware of outdoor air pollution, but the air quality inside our homes can be an even more significant problem than the air outside.

According to the U.S. Environmental Protection Agency, Americans spend approximately 90% of their time indoors, where pollutants can be two to five times higher than outdoors.

Indoor concentrations of some pollutants have increased in recent years due to factors ranging from synthetic building materials and home furnishings to household cleaners and pesticides.

In Arizona, we spend a lot of time indoors in air-conditioned spaces during the summer months to escape the heat. So we need to be aware of how our air conditioners impact the indoor air quality in our homes.

Here are four ways your air conditioner impacts indoor air quality and what you can do to improve it:

  1. Air conditioners recycle the air in our homes, so it’s crucial we change the filters often in the summer months.

Pollen, dust, and pet dander can circulate throughout your home through dirty air filters.

The elderly, young children, and those with respiratory problems are at the highest risk of indoor air pollutants, especially since they often spend most of their time indoors.

You should be aware that all air filters are not the same.  Air filters have different ratings, and some capture more airborne particles than others.

An air filter’s ability to capture larger particles between 0.3 and 10.0 microns is measured by a MERV rating. MERV stands for Minimum Efficiency Reporting Values.

The higher the MERV rating, the better the filter captures specific types of particles such as dust. MERV ratings range from 1-20.

A MERV rating of 7-12 is common for residential systems, although filters with a rating of 13 -16 are often used in homes for a higher degree of air filtration.

According to the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE), the best rating for residential systems is MERV 13.

However, it’s wise to check with an HVAC pro to make sure your system can handle that rating before upgrading your air filter, as a higher MERV rating can mean lower airflow and your system working harder to cool your home.

Your air conditioner isn’t a substitute for ventilation if you’re doing activities such as painting or sanding inside your home. You’ll need to bring fresh outdoor air in for adequate ventilation.

Although we often keep our homes sealed against the heat while we run our air conditioners in the summer months, opening doors and windows briefly during the cooler hours can help provide some much-needed ventilation.

  1. A poorly maintained air conditioner can negatively impact your indoor air quality, so regular maintenance is a must.

In addition to changing your air conditioner’s filters, your unit’s coils need cleaning, too. Your air conditioner needs regular professional maintenance to run smoothly.

If your air conditioner isn’t working at peak efficiency, it can affect the air quality in your home.

A poorly maintained air conditioner may have more condensation or even be leaking fluids that can promote mold or mildew growth and compromise indoor air quality. The condensate and drain lines can also become clogged over time, trapping moisture and promoting bacterial growth.

Chas Roberts has a 26-point maintenance plan for your air conditioner to keep it working in top condition.

The checklist includes:

  • Check refrigerant levels
  • Inspect disconnect switch
  • Clean condenser coil
  • Test safety controls
  • Lubricate all moving parts
  • And more

All parts of your air conditioner need to be running smoothly to prevent pollutants from entering your home.

Regular professional maintenance will prolong the life of your equipment, keep your air conditioner working at maximum efficiency, and ensure the air quality in your home stays as high as possible.

  1. Damaged ductwork can negatively impact your indoor air quality.

The ductwork in your home is an essential part of your HVAC system. Ducts distribute the air throughout your home, keeping it at a comfortable temperature during the hottest months of the year.

However, since the ductwork in our homes is hidden, we’re often unaware of unseen damage that can affect our indoor air quality.

Cracked or leaking ducts not only waste energy and cost you money, poorly sealed ducts can negatively impact the air quality in your home.

Vermin can also enter damaged or badly sealed ducts in your home, producing waste and compromising your indoor air quality.

Damaged or dirty ducts may have dust and dirt buildup that can blow into your home.  All the air vents throughout your home should be cleaned or vacuumed regularly to prevent dust buildup.

Anything more than minor ductwork repairs should be done by a professional.

  1. An older air conditioner that’s about to fail can impact your indoor air quality.

Air conditioners don’t last forever, and even a well-maintained air conditioner will decline in efficiency as it ages until it eventually fails.

Older A/C units no longer working at peak efficiency may also harbor micro-organisms that can enter your home and compromise the indoor air quality. If the ductwork circulating the air from your older air conditioner is also faulty, you’ll most likely have poor indoor air quality that can possibly threaten your health.

According to the EPA, the health side effects of indoor air pollution include headaches, dizziness, fatigue, and respiratory problems.

Those with chronic illnesses or other pre-existing conditions are especially susceptible to indoor airborne contaminants.

When it’s time to purchase a new air conditioner, a Chas Roberts professional can help you choose a new, more efficient air conditioning system to replace your older unit.


As we run our air conditioners continuously during our hot Arizona summers, they play a significant role in the air quality in our homes.  Changing your air filters every month and choosing filters with the best MERV rating for your system can reduce the number of contaminants in the air and improve your indoor air quality.

Regular professional maintenance of your A/C unit will also help ensure you have the best indoor air quality possible.

Chas Roberts is the largest HVAC and plumbing provider in Arizona and has been family-owned and operated for over 75 years.  Contact us for reliable, quality service.