How to Determine Air Flow When Replacing Your Air Filter

Bearnard isn’t the only one who has experienced problems when replacing an air filter. We have all experienced it at some time or another. You just finished ordering an air filter (from us, of course) and when you try to install it, you’re not sure which direction the air filter arrow should point. Should the arrow point up or down? You go online and search for answers, but none of them seem simple enough. However, the answer to this question is simple. The arrow should always point in the direction the air is flowing. Take it from Alex Hertzog, our in-house air filter expert:

“You need to verify which way the air flows, and the arrow should point in the direction the air is flowing. If the air is not flowing, briefly turn the fan on to verify the direction.”

Like many, you may be wondering why the arrow should point in the direction the air flows. The answer lies in the way the air filter is built. The front side of the filter is the filter media (commonly called “pleats”). The back side consist of metal mesh (or a cardboard frame on some filters).The back of the filter is built as a support system for the front of the filter. You need the air to push the media (front side) into the metal mesh (back side) for proper support.

Now that you know which way the arrow should point and why it should point in that direction, you’re ready to place an order for your replacement air filter.

home Air filter arrow

May I suggest the new unscented, triple-protection Lysol Air Filters? With allergy season in full swing, you may need the first ever asthma and allergy certified air filter to be built. By trapping 85% of pet dander, 92% of dust mite allergens and 95% of pollen, you will experience relief from asthma and allergy triggers thanks to Lysol, the brand we know and love. The Asthma and Allergy Foundation of America loves it, and I believe you will too.

Air filters should be changed regularly, so it is always a good idea to have extras on hand. If you’re not quite sure which air filter is the best fit for you, see Three Questions to Ask Before Buying Your Next Air Filter for additional help.

As always, is here to assist. If you have any questions about which air filter you should choose, feel free to ask below and we’ll be more than happy to help.

6 thoughts on “How to Determine Air Flow When Replacing Your Air Filter

  1. My vent is in the floor what way should the arrow be pointing up toward the ceiling or down in to the vent

  2. Hi Lou, the arrows should point in the direction the air is flowing. For example, if the air is flowing down to the floor, then the arrow should point down as well. This blog can help provide insight: As for your other question, a MERV 8 will do just fine. A MERV 11 is generally more recommended for better filtration, but this can vary depending on the air conditioner unit. If you have been recommended a MERV 8, then it is best (and advisable) to stick with that MERV Rating.

  3. OK, So, when I replace my ceiling filter ,which way should the arrow point
    toward the ceiling hole ? Up pointing to air hole ?
    Or down pointing to the floor?

    By the way ,my house is carpeted.
    has two air conditioners Armstrong ,one on each side outside of the house
    It has been recommended that I use No higher than” Merv 8″for my inside air filters.
    There are so many different air filters to look at in stores with very
    different price ranges . Very confusing to decide ,which will do the job.
    Is Merv 8 best to use?

Leave a Reply

Your email address will not be published. Required fields are marked *