A man changing a furnace filter.
Light brown laminate flooring.

Breathe Easy With a Clean Furnace Filter

How to Change a Furnace Filter

Have you noticed dust bunnies collecting in the corners of rooms? How about that layer of dust coating the book that’s been sitting on your nightstand? And is it all in your head that you’ve been sneezing more frequently?

You’re not going crazy — it’s just time to change that furnace filter. Read on for our handy how-to guide on how to change a furnace filter.

Okay, but First, What’s a Furnace Filter?

A furnace filter is, just as its name suggests, a filter to protect your furnace’s blower motor from dirt. It reduces the amount of dust and dirt particles from gathering inside of your home.

A furnace filter in place purifies the air, limiting allergies and promoting clean circulation throughout your house.

When to Change It

You’ll definitely want to change your furnace filter before you start seeing enormous dust bunnies blow through your house like tumbleweeds. The general rule is to change a basic fiberglass furnace filter every one to two months, but it’s best to check your filter monthly.

You can determine if the filter is too dirty and needs to be replaced by holding it up to the light. If you can’t see the light through the filter, then it’s time to change it.

Changing Your Filter

No, you don’t have to be a furnace expert or handyman extraordinaire to change a filter. It’s simple:

  1. Turn off the furnace.
  2. Find the service panel to the furnace and take it off.
  3. Remove the filter that’s already inside by sliding it out. Look for it near the blower fan.
  4. Slide in the new filter to replace it.
  5. Turn the furnace on once again — you’re done!

Choosing the Right Filter

It can feel overwhelming when you’re faced with several different types of furnace filters. Still, you can narrow down your options by determining your household environment:

  • Does anyone in your home smoke?
  • Have you noticed more-than-normal dust buildup throughout the house?
  • Do you have furry family members who shed?
  • Do you or a family member suffer from allergies?
  • Is your current filter struggling to keep up?
  • Does your heating system fan run frequently?
  • Do you open up your home’s windows and doors often?

If you’ve answered “yes” to any of these questions, then you’ll need to change your furnace filter frequently. We’re talking once a month, and perhaps consider a heavier duty filter.

Types of Filters

You can gauge the effectiveness of a furnace filter by its MERV rating, which stands for minimum efficiency reporting value. The higher the MERV rating is, the better job the filter will perform.

Here are some common types of furnace filters:

Spun Filter: The most basic filters usually consist of inexpensive fiberglass with a MERV rating of four and can be tossed away when they’re changed. While you might instinctively think that the cheaper the filter, the worse it’ll perform, that’s not the case. As long as you don’t have several household environmental factors that would heavily degrade air quality (and subsequently the furnace filter), a basic and cheap one will do the job just fine.

Standard Pleated Filter: Maybe you have a dog or a cat and would like to step up the effectiveness of your furnace filter. Meet the disposable pleated paper filter with a MERV rating range of 6-8. Because they’re a bit heavier than the basic filter, they’ll last longer — about four months. That’s no excuse to skip your monthly filter check-ups, though.

Electrostatic Pleated Filter: These filters have a MERV rating range of 8-12 for household environments that really need a reliable, high-quality filter. Electrostatic filters both filter and magnetically attract and contain contaminants like bacteria, funky odors, and smoke and dander particles. They’re more expensive, of course, and you should only use them alongside an equally efficient vacuum cleaner; otherwise, you’d be wasting your money.

Protect Your Furnace, Protect Your Air

Changing a furnace filter is simple, despite being a somewhat annoying task. When you do check your filter every month and replace it when it’s dirty, you’re extending the lifespan of your furnace and ensuring the air circulating throughout the house is purified.

Remember that a pack of furnace filters is much cheaper than purchasing a brand new furnace.