It was fun to duct tape together four 20" filters into a box shape, slap a box fan on the top, and start filtering my indoor air! It is relatively inexpensive, doesn't use much electricity, and does a pretty good job.

This type of system has been coined a "Corsi-Rosenthal" box more recently, but has been around for some time.

In this episode I dive into: • The history of these types of air filters • Their design (including advanced designs and ones you can purchase) • Pros and cons • How effective they are and where to use them in your home • How they compare to commercial portable HEPA filters • And more

I also back up and discuss indoor air quality concepts in general, and things you can do to your main HVAC system to improve air filtration and ventilation. !

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