Local AC, Heating, & Plumbing Contractor - Mesa & Gilbert, AZ


man with sponge cleaning air vent in Phoenix AZ

Why Do I Have to Change the Filters in My HVAC System?

 |  Air Conditioning, Blog

Many people don’t believe something as simple as changing air filters can have much impact … that is, until they start to replace them on a regular basis. Doing so has an effect on utility costs, air quality, and keeping a house cooler in the summer or warmer in the winter. The filters in your home’s HVAC system are incredibly important for both your comfort, health, and safety.

Clean, high-quality air filters can keep your A/C running smoothly and eliminate particulates from the air you breathe. Here’s everything you need to know about keeping up with your home’s new best friend, the air filter.

When to Change Your Filters

Side by Side of a clean home air filter and a dirty air filter Gilbert AZFor optimal performance, you should change your air filters every month. Through the winter months in the Phoenix area your system normally runs much less. With less dust passing through the filters, you could probably change them out less often. To know if your filter needs changing, check it once a month (setting a reminder on your phone or computer will keep you on track).

If you can still see most of your filter through the collected dust, then it’s OK for a little while longer. If the filter is covered in gray, ashy-looking dust, it’s time to change it before it starts causing problems.

What kind of problems? Dust increases the chance of throat and nose irritation and can cause a constant or near-constant cough. And too much dirt on the filter also makes the system work harder, which uses additional electricity to operate the blower motor and also slows the rate at which a house cools down.

What is a MERV Rating?

A good AC filter doesn’t break the bank, but a cheap filter isn’t doing you any favors. Flimsy cardboard filters allow far too much dust into your system, which can lead to expensive problems in the long run. They also won’t help clean your air of allergens or particulates, so choosing the right air filter is especially important for family members who suffer from asthma or other respiratory disorders. When shopping for a filter, be sure to check its MERV rating, from 1 to 20. MERV stands for Minimum Efficiency Reporting Value. The higher the number, the better the filter.

Thin, fiberglass filters have a MERV rating of in the 1 to 4 range, which is as low as you can go. These filters are not that useful, according to service reviews site, Angie’s List. For most homeowners, the best bet is a pleated air filter with a MERV rating of about 7-13, which filters out a lot of particulate matter without restricting airflow to your system too much.

If you need additional air filtration to alleviate diagnosed or noticeable respiratory problems, try a high-efficiency filter with a MERV rating of 14-16, which will clean the air of about 85 to 95 percent of dust, pollen and other tiny particles.

One thing you have to look out for with high MERV-rated filters is when they’re used with older units with inadequately sized air filter area. We recommend 200 square inches of filter area per ton capacity of each system. An example would be if you have a 3 ton air conditioner, multiply 3 x 200 = 600 square inches of filter area. That would require a minimum filter size 20 x 30.

Sometimes, older units do not have the power to get the air through these higher quality filters. This means the AC unit can freeze or break by working too hard to pull air through the filters. Check your filter size and the system size to be sure your system is working at its peak performance.

Why Air Filters Are So Important

In general, your home’s A/C system (or heater, for that matter) works by using a fan to draw air from the outside into your home through the ductwork. That air then passes over cooling or heating coils, but before it does, it hits the filter.

The filter blocks the vast majority of particulates like dust and pollen from entering your home. This keeps your ducts clean, protects the sensitive working parts of your HVAC system, and keeps allergens out of your breathing space. A clean air filter provides the maximum amount of airflow to your system, allowing it to operate at peak efficiency. Therefore, changing the air filter can provide utility savings.

If people in your home have considerable breathing problems, and you can afford to do so, consider installing Air Scrubbers, which work with your air conditioner to reduce air contaminants, including mold and odor-causing bacteria. Installing an Air Scrubber along with a properly sized air filter can dramatically improve your indoor air quality.

Now that you know the right filter to use and how often you need to change the AC filter, the only thing left to do is to remove your old, dirty filter and pop in a new one. The slightly tricky part is making sure it’s right way up and in the proper position. If you’re not sure exactly how to replace your old filter, check the manufacturer’s instructions for your central air system or furnace.
Schedule A/C Service Now   Call Now