DIY Fresh Filtered Air Intake

Like drinking water quality, air quality is something that you notice right away, whether you’re walking into your home, your friend’s home, or a commercial building.  It’s either not noticeable (good), or noticeably “off”!    Sure, you can take out the garbage or change the cat litter, but if it’s a stale or musty odor, the best prescription would be some fresh air.  You can get fresh, filtered air with a few supplies and a little effort. The first thing to do is to measure the window width where you’d like to install a fan, to make sure you select the right fan for the job.  Many fans work with vertical or horizontal sliding windows.  If there is a danger of children pushing the fan out and/or climbing or falling out of the window, this project may not be for you.

Supplies:

  • Window fan: make sure the fan you select will fit the window you desire (special functions or remote control are not necessary for this project)

  • Filter media: select the MERV you desire.  This media can also be used to upgrade your window AC filtration. 

    • MERV 6

    • MERV 8

    • MERV 13: This would be best for smoke particles or ultra-fine particles in urban air

  • 2” painters tape (used to secure the filter to the fan)

  • Scissors to cut the filter media

Some window fans have reversible motors, so that you don’t have to reposition the fan in order to switch the direction of flow.  For this project, you’ll want to leave the flow direction constant, otherwise the filter may start releasing dust back into your room (not desirable!)  Determine the direction of flow and place the filter before or after the fan in the air flow.  Placing the filter on the suction (intake) side will keep the inside of the fan cleaner.  Also, the filter material shown above has a colored “tacky” side that needs to be placed on the discharge side of the filter.  Basically, cut a piece of filter to cover the fan section and tape it to the fan’s intake (or exhaust if you desire) so that the air entering the room will be filtered, free of bugs, pollen, and dust. If the filter you selected has a colored, tacky side, make sure the colored side is on the exhaust side of the filter.  Here is a schematic and photo:

Once you have the filter attached to your fan, secure the fan in the window by extending the sides to cover the whole opening and pushing the sash firmly down on top of the fan.  Turn on the fan and enjoy fresh air!  You can experiment with the fan settings and position.  For an intake/exhaust configuration, use 2 windows, one with a Window Ventilation Filter installed, and an opposing window with window fan installed, pulling air from the room to the outside.   In this configuration, no filter media (various MERVs above) is required on the fan because it’s exhausting to the outdoors.

Photo by Gabriel Tenan on Unsplash