Step-By-Step Instructions For Replacing Your Air Filter

Regularly replacing the air filter in your furnace protects both your health and budget. Clogged furnace filters can allow debris into the system that can potentially cause damage, increase energy bills, and even create respiratory problems. These simple steps make it easy to change your air filter so that your energy bills stay low and your air stays clean.

1. Choose the correct size.

The size of your filter, called the 'nominal' size, is printed on the side of the existing filter. These are the measurements you’ll need to make reordering a snap. It's important to note, however, that the nominal size will be different from the actual size. A good rule of thumb is that an air filter is ½" smaller than its stated size. So, for instance, a 20x20x1 filter is actually 19.5x19.5 inches.

The simplicity of filter sizing means that if you don't have an old air filter from which to take measurements, all you need to do is measure the actual opening in your furnace. Then, if you take those numbers and round up to the nearest inch, you will have the correct nominal size of filter you need.

If you're in a new home, check the fit of the existing air filter before purchasing new ones to ensure that there are no gaps and that the filter is not bent (don’t do this while the furnace is operating; turn it off first). If you can't find the correct nominal size, you might need to order a custom air filter size to ensure a proper fit.

2. Turn off the power supply.

Most furnaces have a power switch located next to the unit. Be sure to turn this switch to the off position before proceeding. If a switch is not visible, turn off the power at your fuse box to prevent injury.

3. Remove the old air filter.

Furnace filters are normally found underneath the furnace, behind a slotted ventilation cover. Some covers simply pop out, while others are held in place with a few screws. Remove the cover carefully and set it aside. Next, be sure to note whether there are directional arrows on the existing air filter. These arrows indicate the direction the filter should be placed. If there are no arrows present, it means the direction of the replacement does not matter.

4. Dispose of the old product.

The old filter will contain dust and other debris, so it helps to have a trash bag handy and to disturb the old filter as little as possible.

5. Insert the new air filter.

Next, simply insert the new product into the space provided, ensuring that the directional arrows, if any, are pointing in the correct direction.

6. Replace the cover.

Finally, pop or screw the cover back in place for improved air quality, system protection, and reduced electric bills.

7. Buy in bulk or set up recurring shipments.

Once you’ve figured out how to replace your furnace filter, you should make it a regular exercise. It is all too easy to forget about replacing furnace air filters, so it is a good idea to make a note on your calendar or add an alarm to your phone as a reminder to check the the filter’s condition. Buying replacements in bulk or setting up a recurring shipment can also help you keep consistent with your replacements and reduce the likelihood of procrastination. When you set up a recurring shipment with FilterBuy, we reward you with a 5% discount and a guarantee that your filters will always be delivered precisely when you need them.

Studies have shown that maintaining a clean air filter in your HVAC system can reduce electric bills by as much as 15%. During periods of heavy usage, a clogged air filter can increase an electric bill substantially, whereas a new filter costs only a few dollars, so it is definitely to your benefit to stay on top of furnace filter replacement.

Contact FilterBuy to learn more about our exclusive FilterBuy air filters or the extensive selection of other top-quality aftermarket furnace filters we carry. We can help you choose the best size and material for your system to protect both your family's health and your wallet.