Recently we ve heard reports of people making a diy air purifier by taping an hvac furnace filter to a box fan so we tried it and tested it.
Box fan hepa filter effectiveness.
Start off by unpacking the fan and making sure that it works.
This article is based on the 3m merv 12 20 x 20 pleated filter and the web absorber cut to fit 20 x 25 filter.
Yes putting the filter behind the fan will prevent dust from hitting the motor and collecting on it.
Yes hepa will provide more filtration but if cost is an issue than the diy merv 13 box fan is a sensible choice.
The filter dramatically decreased the amount of black carbon in the room within 30 minutes.
People run unprotected fans we just call them fans all the time and it doesn t seem to cause much harm.
Building the box fan air purifier.
But here s a gut check.
20 inch box fan.
I think there s a small non zero benefit of that although i haven t seen anyone actually test it.
Point that in the right direction and then tape onto the front of the box fan filter.
0 01 micron 10 nanometers and above.
Make a hepa air filter out of a box fan and hepa furnace filter.
Fan 20 x 20 box fan any model and manufacturer filters depends on your needs and research findings.
Merv 13 box fan set up at 2 feet from particle counter.
But it s not as strong as any of the actual air purifiers we tested.
Hepa air purifier aeramax 300 set at 2 feet from particle counter.
The wirecutter reports that this solution is effective although not to the degree of a dedicated machine.
There will be a little arrow on the filter showing which way the air should flow.
If you want to use pleated filters and higher merv filters the only safe way to do so is have a 5 6 inch media filter installed by a professional.
As you can see in his video demonstration terrell tapes a 20 by 20 inch whole house air filter merv 13 or higher which sells for 15 over a 20 inch square box fan which you can find for.
1 inch pleated filters are 2 3 times more restrictive than fiberglass filters right out of the box and can easily become too restrictive within 30 days of use.
It falls squarely within the particle size range that hepa filters capture with extraordinary efficiency.
20 by 20 by 1 merv 13 furnace filter.
Some have wondered whether we should tape it onto the back of the box fan filter.
This graph from puget.
Further testing needs to be done with higher merv ratings and over longer periods of time.