Which Way Does My Air Filter? Man installing filter in furnace.

Which Way Does My Air Filter Go?

You need to change your air filter, but it has been a while, and you aren’t sure where to start. Never fear, we’re here to help! Clean air filters improve your indoor air quality and minimize the wear and tear on your Heating, Ventilation, and Air Conditioning (HVAC) system. When you insert your air filter the wrong way, it can’t filter your home’s air efficiently, which can lead to a variety of maintenance problems. You can experience even worse problems if you never change your air filter at all! Here we dive into how to replace your air filter the correct way in five easy steps.

1. Turn Off the Power to Your Furnace or Air Handler

Your air filter can collect a lot of dust, so it’s important to always turn off the power to your furnace. If the power remains on, your HVAC system will circulate dust, pollen, and dirt through the vents and into your home. Yikes!

2. Locate the Air Filter You’re Replacing

In most instances, your filter is located near your furnace. If you need help locating your furnace or air conditioner filter, then click here. You may have a return air grille, air cleaner cabinet, or media type filter. It all depends on your type of HVAC system.

3. Discard Your Old Filter

Be careful when you pull out your old air filter since it has probably collected quite a bit of dust and other particles. To properly dispose of the used filter, place it in a large trash bag, tie it up, and place it in an outside garbage bin. If you’re worried about throwing your air filter away, check out our washable filters.

4. Insert Your New Air Filter

Luckily, most air filters are designed so that they will not fit properly unless they are inserted correctly. Look for the airflow arrows printed on the side of the air filter that indicate which direction the filter should be inserted. (Shown in the image below.) When you insert the new filter, the arrow should point toward the furnace.

Airflow Indication Arrows

5. Turn the Furnace Power Back On

Now that you’ve learned to properly change your air filter, you can enjoy your clean, filtered air! Need new filters? We have you covered with high-quality filters at the lowest prices.

NOTE: In case your filter is missing an airflow arrow, there is typically a wire mesh on the downstream side of the filter. This wire’s purpose is to give the filter the rigidity and strength it needs to capture particles. If your air filter doesn’t have an airflow arrow, then make sure the wire mesh is facing the blower of your HVAC system since this is the last surface the air touches.

For any other questions concerning your home’s air filter, talk to our customer service, comment down below, or visit the air filters section of the blog.

41 thoughts on “Which Way Does My Air Filter Go?”

  1. What if there is no arrow on the filter? I have a heating system that I use a reusable (washable) filter for and there is no arrow on it.

  2. There is no arrow…really, there isn’t. There is the model number on the side, and I’ll assume that up on the letters and numbers is also up for the placement.

  3. Regarding the comment: “When you insert your new filter, the arrow should point toward the furnace.”

    My vent is in the ceiling. Does that mean the arrow points down?

  4. My ceiling filter has no arrow or mesh edge. Both sides look the same. I just removed a 4 mo old filter and it didn’t look dirty. Now wondering if it was inserted right

    • Hey Betsy! In this case the filter can likely be inserted either way. If it doesn’t appear dirty then it might be okay to keep. Is this a pleated or fiberglass filter?

  5. I bought a washable filter and it looks the same on both sides…so does it matter which side is which?

    • Hey Ed! Some of our air filter models are designed to have a directional airflow. Check the label on your filter frame before you install it. If the label does not have an airflow arrow, it means that the model design can be installed on either side.

  6. So following that logic Dennis; our house has two floor levels, the lower level has three ceiling filters and the upstairs level has two separate ceiling filters. All ceiling filters should have the arrows facing up towards the roof.

    Our HVAC system does not have a filter near the air handler & furnace which is located in the attic. It is the dustiest house I have ever lived in and is only 5 years old. Is there a way to add a filter at the air handler.?


  7. My filter inserts into the furnace. And it is 20×20 so no clue there. Have any suggestions as to which way it goes. . The return. Flow comes in under the filter. So does the metal grid go up or down? Thanks!

    • Hey Judy! If there’s no arrow on the filters, make sure the metal mesh is facing the HVAC blower. If the air passes under and through your filter, the mesh side will face upwards.

  8. My filters don’t have an arrow.
    One side is dark orange and the other side is very light colored…help ???

  9. When installing new furnace filters and filters go in the grill/door which way should the metal mesh side be? Next to grill or facing inside towards furnace?

    • Hey Nancy! The mesh side will face towards the furnace. Think of the metal as a support that sits behind the filter media to keep its rigidity as the air passes through it. Hope this helps!

  10. I live in a small apartment and my furnace is located in a closet type area. Does that closet act as a return? It has a vent at the top of the closet. So the arrow points toward the furnace? Right?

    • Hey there! We’re not sure if the return is located there or elsewhere in the apartment. The arrows on the filter should point toward the furnace to have those arrows pointing the direction of the airflow through the ducts and into the furnace. Hope this helps!

  11. I have a airfilter and arrow is pointing down for airflow which way should i put it in for a ceiling

    • Hey Hannah! I’m guessing that this is a return air vent. In this case the arrow would be pointing up as the air travels up through the vent before being pumped into the HVAC unit. Hope this helps!

  12. this did not help me at all.my filter is in front of the ac unit.so the arrow would have to be pointing straight forward to be pointing to the unit.up or down does not point to anything but the ground or the roof.my filter has to be laid down flat not sideways.

    • Hey Joe! If your filter lays flat or horizontally, you’ll still use the same idea of pointing the arrow in the direction of the airflow. If the air flows through the filter before moving into the HVAC system, then the arrow will face towards the blower. If the filter is after the system in terms of the airflow stream, then the arrow will point away from the system. Perhaps this video will help: https://www.youtube.com/watch?v=iVYdDifRvbg

      We hope this helps!

  13. I have a washable air filter
    No arrows
    One side has downstream writing on it and it is smoother than the other side
    Does it mean the downsream side is the inside and the other side is outside?

    • Hey Haney! Does either side of the filter have any metal mesh? If so, that side will face towards the blower of your system. If there’s no mesh, the side labeled downstream will face towards the blower. Hope this helps!

    • Hey Betty! The downstream side will face towards the furnace or on the inside of the grill. Hope this helps!

  14. Can you please help I’m having lots of confusion. I have a ceiling filter where the air is being sucked in. If I install the filter according to the arrows the metal mesh side will be down facing the grill and not the furnace as you have stated in here to someone else. So is that the proper way or should I place it the other way so
    That the wire mesh is facing up but the arrows down even though the airflow is going up. This is where the confusion lies.

    • Hey Joe! The mesh should be on the opposite side of the grill. That way the air flows through the filter before hitting the mesh. Hope this helps!

  15. i have two air filters, both ‘intake’. my A/C unit is on top of my house. so, i face the arrow of the filter the same direction of the airflow, correct?
    Second filter has an option to ‘open or close’ vent – what should I do? keep it open, or closed?

  16. I have a ceiling filter. I bought one with a wire metal on one side. But I see two arrows going two different directions on the filter side. One is just a plain arrow, the other arrow says air flow. Does the wire metal go up towards my furnace or does the wire metal go downward towards the grill floor? Confusing.

  17. I have a coleman evcon with two filters on the door, the upper one is up by the blower the bottom one is closer to the condenser coils. Do they both go the same way.? It seems like the arrows are not the same? Or did i have them wrong all a long? I put the top ones with the the wire mesh facing the furnace. I want to get this right because last summer my bills were 300 a month for a small single wide trailer.

  18. I recently bought a filter that has carbon particles on it. The arrow shows the carbon side being inserted on the side that the mesh usually goes, and the mesh on the opposite side. Is this a packaging error or is this correct?

  19. I have a home made air purifier that I made out of salvaged parts from a bargain bins type situation… while I know this is not ideal it DOES work. My problem comes from the fact that the newest batch of filters I salvaged have neither air flow arrow indicators or a wire mesh, it is multi stage with a fiberglass removable layer (velcro) an activated carbon honeycomb layer, an finally a pleated paper layer with VERY thin fiberglass layer attached. Which way does the air flow?

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