HVAC 101: Air Filter Arrow Direction

What Direction Does the Arrow Go on a Furnace Filter?

When installing an air filter, do you know what direction to put it in?

It may seem like a simple thing, but it’s not uncommon for a homeowner to be unsure about the air filter arrow direction. Each furnace is different and how you installed the air filter on your last HVAC system is probably not the same way your new system is set up. Or perhaps you are new to home maintenance and this is your first time ever changing an air filter.

At Frederick Plumbing Heating, Air Conditioning, we know how vital is it for homeowners to change their air filter regularly. Having repaired heating systems across Wichita for decades, we’ve seen the problems and damage caused by not having adequate air filters in a home’s system.

Not changing out your air filter as often as it needs can lead to a lot of problems.

• Poor indoor air quality
• Foul odors
• Furnace not heating efficiently (aka *higher energy bills!)
• Heater breaking down or not heating properly
• Furnace breaking many years before it should!

*According to the United States Department of Energy, a furnace or air conditioner operating with a dirty or clogged air filter can cause your energy consumption to increase by 5 to 15 percent.

What Way Should the Air Filter Arrow Direction Point?

What is air flow direction? It’s simply the way the air is moving through your HVAC system. While many people think of air filters as furnace filters, in most systems, these filters are for both your furnace AND air conditioning. That’s why it’s vital that you make sure there is a clean air filter installed in your system all year round.

A part of your heating system is heating the air. Then a fan pushes that heated air through your system and into your duct work. That’s how all that warm comfortable air makes its way up through your vents.

How do you know what direction your furnace’s air flow is going? Well, if you already have a filter in the system, you can simply refer to what direction that arrow is pointing. Then put your new filter in with the arrow pointing in the same direction.

However, sometimes this is not a sufficient solution:

The arrow needs to be pointing TOWARD the unit (technically, the blower motor) and AWAY from the return duct. If your filter is on the wall, the arrow should face the wall. If your unit is on the ceiling, it should point towards the ceiling.

If you have the manual for your furnace or other HVAC system, you can refer to it for arrow facing instructions.

You should never put an air filter in wrong. You always want to make sure you install it in the right direction. Putting it in wrong could reduce proper air flow, which can result in inefficient heating and a lot of potential furnace problems – most that are a LOT more expensive to fix than a new air filter.

A Filter Without An Arrow?

It’s very rare that your filter does not have an arrow on it. Be sure you are looking at every part of your filter before you give up finding an arrow.

Pro Tip to NEVER Wonder About Air Filter Arrow Direction Again

Our best tip requires only a marker. Once you’ve identified the correct direction for your filter arrow, simply draw an arrow with a permanent market in that direction right on your furnace. That way, even if you forget to check the arrow before it’s removed, you will always have this mark to provide you with the answer.

Call Frederick for Help with Your Air Filter

Frederick Plumbing, Heating, Air Conditioning has been services homes and businesses in Wichita since 1918! We’ve repaired every type of furnace and heating system and can be counted on to fix whatever problem you are having.

We provide a professional heating tune up service. We will make sure your system is running efficiently and safely. If it’s dead, call Fred! We are available for 24/7 Emergency Repair. Call (316) 262-3713 or send us a message online.