If you want your air conditioner to function optimally, you need to take good care of it. One of the most important things any homeowner can do is change the air filter on a regular basis. This allows your HVAC system to work its best, but many people are left to wonder how often these filters should be replaced. The answer will depend on certain factors. Here’s what to know so you can keep up with the care of your air conditioning system.

How Often to Change the Air Filters in Your AC Unit

In Houston, the general recommendation for changing air filters in the HVAC system is every 30 days. This will depend on the kind of filter you use, as those less expensive fiberglass filters aren’t designed to last longer. If you use a higher-end type of filter, you may be able to go longer before replacing it. However, the best thing you can do is check it every 30 days, and if they aren’t covered in dust and dirt, plan on changing them every 90 days.

The longer your air filter is in place, the more it gets covered with dust, dirt, allergens, and pet hair. This means it will decrease the efficiency of your air conditioner. There are other factors to consider in your home that may make you want to change the air filter with more frequency.

Allergies or Asthma

If someone in your home suffers from allergies or asthma, they are more sensitive to airborne particles in your home. It is important for you to change the filter every 4 to 6 weeks if anyone in your home has these issues.


If cats or dogs are a part of your family, the hair and pet dander they shed can more quickly clog up your air filter. You’ll want to stay on top of changing your filters each month for optimum AC efficiency.


Parents of young children should ensure the air quality is top-notch at home. Doing so can prevent illnesses and help keep the home clean. Make sure you check and change your air filter monthly.

What Factors Impact the Lifespan of HVAC Air Filters?

As you consider how often to change the air filters in your HVAC unit, think about the following factors.

How Often You Use Your HVAC System

When it’s hot out in Houston, your AC will run on a nearly constant basis. You will want to change your filter every month to keep your system from being overburdened.

The Size of Your Home

A larger home means your AC will have to work harder to pump enough cooled air into your home. However, just because you have a smaller home doesn’t mean that filter can’t get dirty as quickly.

Your Indoor Air Quality

The outside air quality will affect indoor air quality. If the air quality outside is poor or you have pets inside, you’ll need to replace your air filter more frequently.

What Happens When You Don’t Change Your Air Filters?

The air that circulates through your home all passes through the air filter. This simple filter is responsible for protecting your HVAC system. If you don’t keep them clean or change them, it could cause your system to break down and lead to damaged parts.

Dirty air filters reduce airflow in the system, which makes the fans work harder than necessary. This means they’ll wear out more quickly. You’ll also cause your home’s energy usage to skyrocket, which means higher electric bills.

Air filters are designed to keep out particles and contaminants. Not only will a dirty air filter cause you and your family to keep breathing these things in, but also, you will slowly cause more wear and tear to your HVAC system.

Hold your air filter up to the light, and if you can’t see the light coming through, it’s time to change it. Check these filters every 30 days to be on the safe side and avoid the need for emergency repairs.

Don’t forget that in addition to replacing or cleaning your HVAC filters; you should schedule Houston HVAC service to keep your system well-maintained throughout the year.