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Discussion Starter · #1 · (Edited)
Every furnace has a space for an air filter. The air feeding into your
system runs through the filter which catches dirt, dust and allergens.
Replacing the filter is a simple process, and it will help your furnace
run more efficiently. If you have never replaced one before, you will
be amazed at how easy it is.

Locate the Filter

This is actually the most difficult part on most furnaces. The filter
will be in one of two areas. It will either be near the intake behind a
large ventilation grate, or it will be near the furnace itself where
the return air duct feeds back into the system. The air intake filters
are easy to find because the ventilation grates are large and will stand
out. To locate the filters that are in-line with the return ducts, go
to the main furnace and look at the duct-work going into the system
around the bottom. You should see a tall and narrow opening at the
junction between the duct and the furnace. There should be a strip of
cardboard inside that opening. That cardboard strip is actually one
edge of the filter.

Remove the Old Filter to Find the Size

If you have an intake filter, you may need a screwdriver to pull the
grate off and access the filter. If the furnace filter slips into the
duct-work by the furnace, then you can just pull it out of the unit. The
size will be stamped along the cardboard edge that surrounds the
filter. Put the existing filter back in place until you can go the
store and buy a new one. It’s important to actually write down the size
when you go shopping so you can be sure to buy the proper one. There
are many different sizes and they all start to sound alike, so it’s
better to write it down than trying to remember.

Choose the New Filter

As with so many things in life, furnace filters come in an incredible
range of styles. You can pick up a basic filter for a few dollars, or
you can spend $20 on a single filter. The difference is the quality and
how effective the filters are. The more expensive filters capture
smaller particles, filter more allergens out of the air and ensure that
the air moving through your furnace is as clean as possible. They are
highly recommended if you suffer from allergies or have animals in the
home. However, the less expensive filters will work nicely for most
households provided they are changed on a regular basis.

Buy Extras

Whenever possible, buy more than one filter. It’s easy to forget to
change the filter, but you can slip the new one in when you remember if
you have it on hand. Stores also sell out of different sizes, and you
don’t want to be stuck with an old, dirty filter because the store is
waiting on a shipment.

Switch the Filters

Have a plastic trash bag ready to put the old filter in when you remove
it. This prevents the dust from spreading around your home. Once the
old filter is removed, slip the new filter in place. Look on the
cardboard border for arrows indicating which way the air should flow.
If you have an intake filter in the wall, those arrows should point away
from the room and towards the duct. With a furnace filter near the
main unit, the arrows should point away from the duct and toward the

It’s important to change your air filter once a month. This keeps the
air in your home cleaner, improves indoor air quality, protects your
furnace from dirt and dust and helps the system run more efficiently.
The cost of your air filter will easily be recovered through lower
operating expenses and prolonged furnace life, so take the time to
change your air filter regularly.

Billy and Ginger Gouty started their business, Service One AC in 2003. They take great pride in servicing the Florida area, and feel particularly proud to help the community in which they currently raise their children in, the Seminole and Orange County area. You can follow Service One AC on Twitter at: https://twitter.com/ServiceOneAC

15 Posts
if you are in the southern United States like us here in Florida I have found that the more air flow the better the performance when it comes to air filters. You may want to consider fiberglass filters instead of the paper faced filters as these types of filters seem to restrict air flow when it comes to air conditioning systems.

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