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How to Change Your Air Filter at Home

By October 19, 2021Home

Home air filter replacement is one of the easiest ways to ensure that your furnace and central air system runs at peak efficiency. A clean air filter can reduce your energy costs and minimize the risk of germs and mold growing in your air system.

You should inspect your filter monthly when the system is regularly operating–for instance, in winter when the furnace often runs–and change the filter every three months. When you hold the filter up to a light, you should be able to see through it. If the filter is dirty or damp when you check it, replace it with a fresh one.

What air filter do I need for my house?

Look at your old filter. To ensure that you are buying the correct replacement filter, pull out the current filter and look for the size information. A normal air filter size is 20 x 20 x 1, indicating that the filter is approximately 20 inches square and one inch thick. As you remove the old filter, take note of the direction that the arrow (on the outside of the filter) is pointing, so you get the new one installed correctly.

If you are concerned about buying the wrong filter, take a photo of the old one or, better yet, take it along to the store. A word of caution on filter size: Do not measure the old one to determine the size since they are typically smaller than the dimensions shown on the filter. Go by the size stated on the filter.

Choose the MERV rating for the filter

MERV is the Minimum Efficiency Reporting Value, meaning how well the filter captures small particles. However, keep in mind that more effective filtering translates into using more energy. Many experts view a MERV rating of 6 as an acceptable compromise between effective air filtration and higher energy bills.

But if there is a reason for concern about air quality—smokers, pets, allergies, asthma, or excessive amounts of dust in the environment—purchase a filter with a higher MERV rating of between 7 and 12. While it might raise your energy bills, it could be well worth it to improve your home’s air quality.

Changing the air filter in your home

If you have central air and heat, find the unit that cleans and circulates the air. It will usually be in the basement, a closet, or some little area out of the way. Follow the pipes or ductwork, and they will lead you to the heating, ventilation, and air conditioning (HVAC) unit.

Look for the air filter slot in your unit. On an HVAC unit, this will often be somewhere between the air handler and one of two plenums: the supply plenum that connects to the ductwork that heats and cools the house and the return plenum that sends “used” air back into the HVAC unit. Either way, the filter will be near the bottom of the unit and will be inside a long, thin opening with a removable cover.

If you cannot find the filter slot on your HVAC unit, look in the vents that blow air into your rooms. Some systems may have their filters in the return air vents, but only if the system has no more than two vents.

To be on the safe side, turn the unit off before changing the air filter

Turning it off will prevent particles from getting into the system when you remove the old filter. It could also keep you from being hurt.

  • Gently slide out the old filter to keep it from dislodging the dirt that accumulated on it.
  • If you have a hard time removing the filter, try attaching a folded piece of duct tape to the side of the new air filter to use as a handle for the next time.
  • Put the old filter directly into a garbage bag and carry the bag to the trash can. Doing it this way will avoid losing any dirt or dust particles on the way there.
  • Insert the new air filter into the slot, making sure the arrow points in the correct direction. Check to ensure there are no gaps (a sign that you may have the wrong filter).
  • Turn the unit on to ensure everything sounds right. Call an HVAC technician if you hear or smell anything unusual or if the system fails to start.

Can we offer any other tips for maintaining a healthy home environment?

The insurance experts at White Cloud Insurance are here to help. We are in the business of helping people protect what they worked hard to build. We represent some of the finest and most reputable insurance companies in the country, and we will work with you to find the best coverage.

White Cloud Insurance is an independent insurance agency in Miami, Florida. Get in touch through their contact form, call them at 305-556-1488 or email them at