Want to make your own DIY air purifier at home?
Check out our step-by-step instructions.
For a printable one-page PDF, see this link.
Materials Needed:
Lasko 3-Speed 20” x 20” Box Fan (or equivalent)
20” x 20” x 2” MERV-13 Filter (note exact dimensions)
Hot Glue Gun and Sticks
Masking Tape
1. Unbox the fan. Insert the included plastic "feet" on the bottom frame of the fan. Keep the box.
2. Optional: Gently apply foam weather stripping to the perimeter of the fan's backside frame, starting and ending at the midpoint between the feet. The foam should go over the feet, half on the edge. Avoid stretching the foam, as the corners may fall off due to tension. Total foam used should be slightly less than 6'.
3. Using the hot glue gun's lowest setting, gently reinforce the fan's outer rounded corners by squeezing the glue gun evenly and pushing the bead of glue in front of the tip as you apply. Avoid contact between the glue gun's metal tip and the foam, as the heat will melt the foam. (Optional: glue all around the outside perimeter of the foam to ensure the foam does not fall off)
4. Using the box's packaging or other cardboard, make a cardboard shroud. See our separate instructions for this: commonhumanitycollective.org/make-an-exhaust-shroud
5. Cut each of the 4" x 4" labels diagonally in half. There should be 4 total triangles for each corner of the MERV-13 Filter.
6. Orient the filter so that the exposed wires are facing up. Apply a triangle sticker label to a corner of the MERV-13 filter to ensure the label is blocking off air flow. Repeat for all four corners.
7. Place the box fan upright on its feet. Take the the MERV-13 filter and orient it so that the air flow arrow is pointing towards the back of the fan. The exposed wire should not be visible, for it will be facing the back of the fan. Check all edges to make sure the filter is on top of the foam seal. There should not be any gaps between the filter and the foam. Once properly aligned, use masking tape to temporarily secure the filter in place.
8. Lay the device on its side. If possible, use two people. Have each person take one end of the band and stretch the band around the fan, filter, and cardboard shroud. The band should sit right outside the fan's feet. Avoid shifting the filter, for this will break the foam seal. Repeat on the other side and make sure the bands are square and parallel. For easy transport, wrap the cord and slip under one of the bands.
Do you need more guidance?
CHC organizer Chris will demonstrate how to assemble an air purifier from the above materials in this video.