Not Visible

For people who are having particular problems with air quality, something like this might help.

I built this device for a friend of mine who lives in an apartment that doesn't have forced-air heating, so she doesn't have a heater filter that pulls smoke out of the air.

This is just a 24x24 heater filter from Home Depot in Emeryville, taped onto one end of a 22x22 moving box, also from Home Depot, using 2-inch packing tape, with a 20-inch box fan taped onto the other end so it pulls air in through the filter. 

Home Depot was out of the fans but I had one at home. 

It just took me a few minutes to cut up the box with a pair of scissors and tape it all together.. Other than the fan, it cost less than $20. The fans are cheap too, if you can find one for sale this time of year. 

I replaced my heater filter today and it was much much dirtier than I have ever seen one. So it might be a good idea for people to replace theirs even if it wouldn't normally be time for it. 

Here is how I put it together: 

1) For the filter end of the box, cut off the flaps so they only stick out
1 inch.

2) Fold them outward at a 90 degree angle. 

3) Run tape along the box side of the flaps and fold the tape over 

lengthwise onto the outer sides of the filter. Make sure the air 

flow direction marked on the filter points into the box. 

4) Run more tape along on top of the tape mentioned above,
on the outer edges of the filter and fold it lengthwise onto the
side of filter that is facing us in the photo. 

5) For the fan end of the box, fold the flaps into the closed position 

and cut a 16 inch square hole in the middle of them. Leaving 

a 3 inch perimeter of cardboard. 

6) This make 4 U-shaped flaps. 

7) Tape the inner pair of flaps together where they meet, wrapping 

the tape around the joints like a bandage. 

8) Cut off the arms of the U-shaped outer flaps so there is a 3 inch 

wide piece on the left and right of the fan. 

9) Set the fan on the floor, so the bottom is lined up with the bottom 

side of the box. 

10) Tape the outer flaps to the left and right sides of the fan. Make 

sure the fan is blowing air out of the box. 

11) To make the X patter of tape shown in the photo, run tape along 

the length of each 3 inch outer flap and diagonally across the 

side of the box and around the corner by a few inches. Use one 

piece of tape for each direction of each flap. 

Now plug it in and turn it on. Try the lowest speed setting first to be sure the box doesn't crumple. For maximum filtering, use the highest speed on the fan that doesn't crush the box. 

This is a temporary device only intended to last a few days, so keep an eye on it and make sure it doesn't have any problems.