FiltAirs DIY Air Filter

A box fan and two furnace filters taped into a triangular air cleaner.

FiltAirs DIY Air Filter by Open-Source-Imports
https://thediyjunky.com/@open-source-imports/filtairs-diy-air-filter
Licence: CC-BY-SA-4.0

Adapted from: https://www.appropedia.org/535_FiltAirs_DIY_air_filter
Original author: Bikash Pradhan, Nicole Salas, Amin Younes
Original licence: CC-BY-SA-4.0


The finished unit

Summary

A low-cost air filtration unit built from a box fan, two filters and cardboard, assembled with duct tape.

Parts

Part Size / spec Qty Unit cost

Required total: $0.00

Tools

Build steps

1. Place the fan face down

Place the unit face down with the inlet side up.

2. Attach the first filter

Attach the first filter

Place one filter on the unit and align it with the edge of the box fan, and verify that the arrow on the filter points towards the fan.

3. Form the triangle

Form the triangle

Sit the unit up and pull both filters out to form a triangle, and secure the point of the triangle.

4. Cut the cardboard triangles

Cut the cardboard triangles

Using the box that the box fan came in, or other cardboard with at least 20x20 inch dimensions, cut out two triangles.

5. Cap the top

Cap the top

Place one triangle on top of the filters, making sure the cardboard slightly overlaps onto the filters.

6. Secure the edges

Secure the edges

Gently fold the edges of cardboard to sit flush against the box fan and secure with duct tape.

7. Cap the bottom

Cap the bottom

Flip the unit over so the bottom of the fan is facing up, and attach the other triangle to the bottom.

8. Seal it

Seal it

Lay the unit down with the box fan on the ground and the point of the triangle facing up, and seal the remaining edges.

9. Use it

Use it

The unit is assembled and ready to be used. Place the unit sitting upright in an open area.