How to Change Your Furnace Filter (And Why It Matters!)

Replacing your furnace filter is a quick, easy, and impactful way to improve your home’s indoor air quality and save a little money on your monthly energy bill. The hardest thing about replacing your filter isn’t the installation process; it’s remembering to do it! Read on to learn how often to swap out your furnace filter and how it impacts your home.

What Does a Furnace Filter Do?

Furnace filters trap airborne particles circulating in your home. Trapping irritants like dust, hair, and pollen improves indoor air quality and protects your furnace from wear and tear. Over time, even tiny particles can reduce your HVAC system’s efficiency and shorten its functional life span. Furnace filters are the first line of defense for you and your furnace!

How to Change Your Furnace Filter

Most homeowners can replace a furnace filter in just a few minutes. Once you’ve found the correct replacement (more on that later), follow these step-by-step instructions.

  1. Power off your furnace. While the filter and filter cover will only be removed for a few minutes, you’ll still want to turn the furnace off to prevent unfiltered air from blowing into your home. Turn your thermostat to “Off” or “Auto”—no need to turn off power at the circuit panel.
  2. Find your air filter panel. You can find most residential furnace filters in a rectangular panel on the furnace. It usually looks like a computer tower. Find the handle or tab to open the cover and pull. There are typically visual instructions on the panel itself.
  3. Remove the old filter. Pull on the filter to remove it and throw it away immediately.
  4. Install the new filter. Your air filter panel will have an arrow indicating the airflow direction. Slide the new filter in. The arrow should point toward your furnace, matching the airflow direction from your ducts into your furnace.
  5. Replace the cover. Snap or slide the panel back into place.
  6. Power the furnace back on. Flip your thermostat back to “Heat.” That’s it!

How Often Should You Change Your Furnace Filter?

Replace your furnace filter every 1-3 months to maintain indoor air quality, reduce wear and tear on your HVAC system, and lower your monthly energy bill. This 90-day period is the widely accepted benchmark, although additional factors may shorten your replacement interval to 1 month. You may need to replace your filter more often if:

  • You have pets. Fido’s fuzzy fur might be adorable, but pet hair and dander can clog filters quickly. Especially if you live in a smaller home or have more than one furry friend, consider replacing your filters more frequently.
  • You have a crowded home. The more, the merrier! Having everyone under one roof is fun, but it usually results in more dust and airborne irritants. Maintain healthy air quality by replacing your filter sooner than the 90-day mark.
  • You have underlying respiratory issues. Allergy and asthma sufferers rely on low pollen, dust, and dander levels to find relief at home. If you or someone in your household battles seasonal allergies, asthma, or another respiratory condition, replace your filter every month. This is especially important during peak seasonal allergy season, which is typically April, May, or June, depending on where you live.

Related: What Do MERV Ratings Mean?

Don’t Wait Too Long...

Wondering what happens if you don’t change your furnace filter? You don’t want to find out. Dirty furnace filters pose short and long-term problems for homeowners.

Short-term Problems

  • Poor indoor air quality
  • Lower energy efficiency
  • Increased heating and cooling costs
  • Poor airflow

Long-term Problems

  • Frequent emergency maintenance calls
  • Broken parts
  • Shorter unit lifespan

How Do I Know What Furnace Filter to Buy?

Furnace filters have all their size and compatibility information printed directly on them, which makes it easier to make sure you can find a compatible replacement. Check your current furnace filter for two key numbers.

1. Dimensions – Furnace filters come in several sizes that fit different furnaces. The three most common sizes for furnace filters are:

  • 10” x 20” x 2”
  • 14” x 20” x 4”
  • 16” x 24” x 2”

If you’re unsure which size you need, contact your furnace manufacturer for help.

2. MERV rating – Short for “minimum efficiency reporting value,” MERV ratings range from 1 to 16, with 16 filtering the smallest particles. Most homes use a filter with a rating between 8 and 12, but check your owner’s manual to see what’s compatible with your furnace system.

Maintenance Makes All the Difference!

Replacing your furnace filter is just one easy way to get the most out of your heating and cooling system. You don’t have to do it alone. Cincinnati families have relied on One Hour Heating & Air Conditioning for year-round HVAC maintenance and repairs for years. See what sets our trained, friendly technicians apart. Book an appointment or call (513) 815-3460 today!