With the different types of pollen floating around, it’s no wonder most of everyone is coughing, blowing noses, and sneezing up a storm.

If you don’t have the cash to spend $800 on an air purifying system, you’re in luck, and if you do, we need to talk. There’s no need to be miserable at home anymore.

Dr. Jeffrey E. Terrell, director of the University of Michigan’s Sinus Center, shows you how to make an air purifier for less than $30 to help decrease indoor allergens. All you need is a HEPA filter, some tape and a cheap box fan—you can find all of these items at your local hardware store.

It’s as simple as taping a 20” x 20” furnace air filter (MERV 13) in front of the box fan, and turning it on. Dr. Terrell uses a particle counter to show you the difference between one of those expensive purifiers compared to the one you can make at home.

This University of Michigan professor claims his DIY system will cut down indoor allergens by 90%...not bad a bad gig at all. Looking at the basics of his configuration, the homemade air purifier does what any other purifier would do—pull unpurified air through a filter or two.

With this contraption, you’ll probably only need to clean or replace the filter every few months or so, depending on your home and allergies. Pop a homemade air purifier in your bedroom and any other high traffic areas, and you’re good to go. It’s a cheap solution that will help give your nose some relief.

Make a DIY Air Purifier for Less Than $30