When your energy bills begin to slowly rise, you rarely notice it.

You may blame the bill on a variety of things. Perhaps it’s an unusually warm or cold season, where you need more power. Maybe your kids have begun to use more electronics or just forget to turn off the lights.

Few people realize that something as simple as an HVAC filter replacement can lower their power bill and ultimately save their HVAC system from avoidable repairs.

Keep reading to learn about why you need to replace your HVAC filter regularly. This article will even tell you how to know when you need to replace your filter and how to do the job.

Why HVAC Filter Replacement Matters

Even if you have the best HVAC filter at your hardware store, the filter can cause your home and HVAC system harm. Make HVAC filter changes a regular part of your basic maintenance schedule. Failing to do so will result in the following problems.

Moisture and Mold

Your HVAC system does more than pump perfectly chilled and warmed air into your home and building. It also dehumidifies the air so you have perfectly humidified air. Overly humid air creates the perfect environment for mold to grow.

Thus, when you do not change your HVAC filter regularly, you compromise your system’s ability to dehumidify the air and allow potential mold to grow. As this mold grows, your air system circulates the spore-ridden air throughout the home, leading to compromised immune systems and potential mold illness.

Wear and Tear

When your filter is filthy, your HVAC system will work harder and longer to warm or cool your home. It will also allow extra dirt and dust particles to clog your fans and HVAC parts. This contamination will cause excess wear and tear on your system.

Ultimately, you will see your HVAC system will break down prematurely. You will end up paying for a repairman to fix a problem you could have avoided.

High Energy Bills

When you do not replace your air filter, you will ultimately have higher energy bills. Your HVAC system will run continuously, futilely attempting to accommodate your thermostat’s demands. However, the system will take longer than it needs to because of your clogged air filter.

As a result, you will see higher energy bills. Experts estimate that you can lower your energy bill between 5 and 15 percent if you just switch out your air filter regularly.


Generally speaking, you should change your air filter every 30 to 90 days. More expensive, high-end pleated filters will last as long as 6 months. However, you have to take into account that you may not have a high-end filter.

The longer you try to milk your filter’s life, the more likely you are to cause your furnace damage. Several factors play into the frequency of which you should change out your furnace filter.

Breathing Issues

If anyone in your home has allergies or asthma, you need to look into purchasing a HEPA air filter for the HVAC in your home. You will also need to change your filters no less than every 30 days.

Indoor air can actually cause just as many problems for people with asthma and allergies as outdoor air does if you do not treat it correctly.


If you are a fur parent with a cat or down, then you understand how odor and dander can build up in the home, especially during the change of seasons. People with pets should change their filters every two months.

Young Children

If you have small children, you need to keep your air clean. This will reduce problems with respiratory illnesses in the small lungs under your roof. Plan on changing your air filter at least every two to three months.

How to Change Your Filter

If you’ve begun to notice higher energy bills, check your air filter. Also, if your AC has begun to pump out warmer, tepid air, check your furnace filter. Here are the basic steps to changing your filter.

1. Find the Filter

You will find your filter in one of a few different areas. Begin with your HVAC manual. This should have directions on how to change out your filter.

If you cannot locate the manual, then begin looking in these areas:

In the return air ducts
Near the blower system
Near the air circulation
In the front and near the bottom of the furnace

You may find your filter with a lid or metal panel that says “filter” on it or the access area may be completely open. You may have to unhook the panel or unscrew the panel.

2. Purchase the Right Filter

Your old filter should have a set of numbers on the side. The numbers indicate the size of the filter. Take note of these numbers by either taking a picture with your phone or writing the number own.

Then head to the hardware store and purchase the correct filter. You may find different filters such as a HEPA air filter for an HVAC or an HVAC UV filter. Regardless of the type of filter you purchase, make sure you take note of the HVAC filter sizes you need.

3. Install

Turn the power off to your HVAC unit. Then open the panel, slide out the old filter, and slide in the new filter.

When you take out the old filter, examine it carefully by holding it up to the light. If you cannot see the light through the filter, you need to replace the filter.

Your HVAC system may have a reusable filter. If that’s the case, call in an HVAC maintenance person. They will give you clear directions on how to clean your filter.

Save an HVAC, Replace a Filter

If you want to get the most out of your HVAC system and save some money on your energy bill, pay attention to your filter. Conducting a basic HVAC filter replacement will protect your HVAC system and keep your air clean.

Do you need some help with your HVAC system? Contact us today. We are a full-service HVAC company that has served St. Louis and its surrounding areas for nearly 40 years.

We have dedicated ourselves to serving neighbors and friends with high-quality services at affordable prices. We can both install and repair HVAC systems. Give us a call today.

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