Mine cost 20 at a local home improvement store.
Box fan furnace filter diy.
That sticking a furnace hvac filter on a standard box fan produces a useful diy air purifier.
This filter will filter pollen dust mites mold spores bacteria proplet nuclei droplets from sneezing and smoke.
But a quick solution as posted by the university of michigan s medical center is to create your own filter using a box fan and a standard hepa filter both readily available in most hardware stores and costing about 25 for everything.
Particle pollution can lead to a number of immediate and long term health impacts such as trouble breathing asthma attacks and lung and heart disease.
Securely fasten a merv 13 filter to the air intake side of the fan.
Apply gasketing to the edges of the air intake part of the fan.
Insofar as filter changing costs you will find that it is still much cheaper to buy furnace filters and variants of them without sacrificing on quality or air cleaning capacity.
20 inch box fan.
I taped a 20 by 20 inch honeywell fpr 9 filter to a lasko 20 inch.
20 by 20 by 1 merv 13 furnace filter.
To get started all you need are a 20 inch box fan and a 20x20x1 furnace filter merv 13 or higher.
Your total cost for a diy box fan filter can be as low as 40 50 00 including incidentals like duct tape or higher depending on the filter options.
There will be a little arrow on the filter showing which way the air should flow.
In 2018 i tested a popular claim.
Purchase a standard 20 box fan.
This project is so simple and inexpensive.
These can be hard to find quickly with the conditions however.