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How to Create Your Own Air Purifier

If you suffer from severe indoor and/or outdoor allergies, then keep reading. You may have an interest in air purification to help better your allergies, or the recent climate of the world—the pandemic and coronavirus—may have you thinking about how dirty the air you breath really is. Purifying your air is easy enough when you really think about it as there are plenty of air purifiers that are made and sold at mostly every store. However, these air purifiers at the store are not cheap, and if you want a super efficient one, or one that can purify air of a larger space, then it’ll cost you even more. Imagine your air purifier stopped working suddenly without warning and, frankly, without reason. You had only had it for a little over a year and only ran it at night to help with allergies. But for some reason it conked out on you. The one you got was maybe the cheapest, but most effective, you could find.

After it died you were faced with the decision to either rustle up the money and get a new one, or just deal with your allergies during the night. You are not willing to spend anymore money on another one if it is just going to die on you again in another year—your allergies are not going anywhere, so you would prefer if the air purifier didn’t either. You’re now met with another, more appealing option. The good news is you can apparently make your very own air purifier at home using something you most likely already have, or can at least get for pretty cheap (and a few other things easily found at a decent price, of course).

This is a great project for those DIYers, but anyone can do it. Air purifiers are basically just made up of HEPA filters, which are high-efficiency particulate air filters. HEPA filters work by pushing air through very fine mesh that traps harmful particles. So if that’s all that is used to make an air purifier, then that is all we need to make our very own, at-home air purifier. You can find HEPA filters mostly everywhere, including Target, Bed Bath and Beyond, and The Home Depot. A good filter is one with a high CADR (Clean Air Delivery Rate) that has been tested by the Association of Home Appliance Manufacturers. This filter paired with filters that have a MERV (Minimum Efficiency Reporting Value) rating of 13 or higher creates what you know to be your average air purifier. You are essentially going to attach the filter to a box fan.

It is important to keep in mind that box fans are not made to withstand the extra driving power to push air through the filters so it may cause your fan’s motor to be damaged after a long run of use. But let’s be real, even if you have to buy a new box fan every few months to withstand the need for the homemade air purifier, it will still be a cheaper investment than the cheapest air purifier you can find in the store. The fact that these at-home, DIY purifiers can only work their best in certain sized spaces must be emphasized. You can’t expect a box fan with some filters on it to purify the air of your entire house, or even your entire apartment (unless it’s a studio), so keep that in mind. This homemade air purifier will do well in a room that usually has a closed door so there is not a constant flow of new, dirty air that needs cleansing. Those minor cons aside, creating your own air purifier is still a great idea that you should look into. Lucky for you I’ve done all the looking into that is necessary.

What you need to build your air purifier:

  • A box fan
  • A cardboard box that is larger or the exact same size as the fan
  • HEPA filters (remember to check the MERV for a 13 or higher rating)
  • Heavy-duty tape (or another adhesive alternative)

Building your air purifier:

*Disclaimer* You could do without the cardboard box, but just attaching a filter to one side of the fan is not as effective as a purifier should and could be. Just a filter attached to the fan will generate what is called bypass; the pressure from the fan spinning will cause the filter to separate slightly from the fan and air will slip through the sides and not get pushed through the filter, allowing dirty air that has not been purified out into your space. Below are the steps to building the air purifier once you’ve gotten all of the needed materials.

1.) Attach the fan to the opening of the box using tape, or the alternative adhesive, to secure it tightly.

  • Keep the box intact and do not open any of the other sides.
  • You can attach the fan with either side facing outward, whether it’s the side that pushes air out or the side that pulls air in does not matter.

2.) Cut out a space on every side of the box (aside from the side that will be resting on the ground) that you want a filter to be attached to.

  • You can choose to use as many filters as you want for the box, but we suggest four filters for the remaining three sides and the top of the box.
  • Make sure you do not cut a space that is too large for the filter.

3.) Attach the filters to the space you cut out, ensuring that there is no space that is not covered by the filter.

Now your air purifier is built and ready to go to work. You can plug in the fan, or just turn it on if it is battery-powered, and the air will flow through the box and out through the filters, creating a lower concentration of harmful particles in your air. We hope this homemade air purifier helps you out as much as it has me.

Filter King’s online store has all the high-quality air filters you need, in any size possible.