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How To: Furnace Filter Guide

July 19, 2016

The Importance of a Furnace Filter

A home’s furnace is one of its most under-appreciated necessities. During the colder months of the year, furnaces are given a workout and without proper maintenance, it can lead to costly repairs or even needing a replacement.

One of the easiest, most inexpensive ways to protect your furnace and keep it running smoothly is to replace the air filter consistently – and use the most energy-efficient type of air filter possible for your unit.

Properly maintaining furnace air filters, and changing them on a regular basis, has a host of positive purposes beyond simply protecting your furnace. When you have a clean air filter, more dirt, dust and debris can be captured from the air in your home, making it cleaner to breathe. This can even heighten the comfort of people who live in the home that suffer allergies or asthma. A clean air filter is also more efficient – helping your furnace to function at a higher level while using less energy. This conserves energy and saves you money.

How Often Should I Change My Furnace Air Filter? says that basic home HVAC air filters should be changed once every month to once every three months — based on the type of furnace you use, and how often it is running. In high-peak months, the filter should be replaced every month if you want to have the cleanest air, and highest efficiency. Newer high efficient MERV 16 Filter can go for up to a year before it needs to be replaced! It’s also important to have a furnace checked by a professional HVAC technician before the peak season starts to make sure it runs smoothly when you need it the most.

Where Do I Find My Furnace Air Filter?

The location of your furnace filter will vary based on your furnace model and how it was installed. The most common places to locate your filter include:

  • The blower compartment. This is likely where you are going to find your filter if you have an older model of furnace.
  • A ceiling or wall grille. Usually it is located near the room or closet that the furnace is inside, and can be unlatched to easily pop furnace filters in and out.
  • In a cabinet with a door, attached to the actual furnace. Based on the model, it can be located on top, bottom or on the side.

What Type of Furnace Air Filter Should I Buy?

Air filters for your furnace will vary based on the type of unit. Furnace filters come as washable versions and disposable ones. Filters are also rated based on their efficiency value, reported in MERV. The higher the number, the smaller the filter particles (and higher the efficiency). Generally speaking, 4-5″ thick disposable furnace filters are more efficient, carrying a MERV rating of 8 to 16! Feel free to check with your trusted HVAC maintenance contractor to determine which type of filter you need for your furnace and home.

How Do I Install My Furnace Air Filter?

Once you’ve replaced your furnace’s air filter once, you will find it pretty easy in the future. The main thing is to ensure that you purchase the correct filter (if you use disposable ones, which are recommended for energy saving purposes). Once you know you have the right one, switch your furnace unit to the off position. Open the slot, grille or compartment where the filter will be inserted, and remove the old one. Slide the new one into place and close the lid/grille/drawer.

Properly maintaining furnace air filters is something that all residents can do with ease. Ask the filtration experts at Bob Jenson A/C for which air filter you should be using, how often to replace it, and what other suggestions for keeping your furnace running efficiently all year round.

About The Author

Bob Jenson

For over 45 years, Bob Jenson has been providing quality heating and air services to the San Diego community.

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