House Air Purifier (COVID & Virus) Under $100

The inspiration for this came from an Ask This Old House Episode and I wanted to make a version that was effective and affordable for my father who just recovered from COVID-19. The end result was a Lowe's curbside pickup order for $90.24 and depending on your timeline it can be cheaper. Enjoy!

4- Merv 13 or higher air filters

• At least one dimension should be 20" but ideal for it to be 20"x20"
• Thickness can be 1" or 2", for the sake of reducing cost I did 1"
• Lowe's has Filtrete 20x20x1 Merv 13 for $19.97 each and save 20% when you buy 4

1- 20" x 20" Box Fan (Note: The switch will need to be on the front of the fan)

• Lowe's had a Utilitech 20" 3 speed box fan for $18.98

Duct Tape or HVAC Tape

• $5 range at Lowe's if shopping all in once place

Scissors or a Razor Blade

Unbox the fan and save the cardboard box to cut out a 20"x20" square

1. Unwrap filters and set the cut out cardboard (bottom) on the floor
2. Set the first filter on one edge of the bottom and make sure the arrow if pointing in
3. Set the second filter on the adjacent edge, ensuring the arrow is also pointing in

Run the HVAC or Duct tape along the entire outer seam of the first two filters, allowing for overlap over the edges.

Note: You are not needing to tape the filters to the bottom just yet.

1. When adding the third filter, notice how the end of the third filter butts up to the second.
2. Tape the second and third filters together
3. Repeat steps 1 & 2 for filter four
4. Tape filter four with filter one

Tape the bottom onto your now taped together four filters.

1. Extend the power cord of the fan to make sure it is not going to get taped inside
2. Ensure the fan is oriented to blow air up
3. Center the fan and tape it along the main lengths with the filters

1. Tape each corner to ensure you are covering all of the seams as well as covering any gaps
2. Slightly tear the tape when going past the power cord, this will ensure you are not leaving any gaps for unfiltered air to leak in

Place the filter near one of the returns for your HVAC, this will ensure your whole house is distributed with your now virus free purified air! Enjoy and post pics of your own!