Blast HEPA Filter

Purifier companies can make obscene profits when most people don’t understand how purifiers work. Here’s the honest truth: a purifier is fan + a filter. In this case, that fan and filter are just huge—20 times the size of our Original DIY HEPAs.

We tested over 10 different HEPA materials before deciding on using an H13, 99.95% HEPA filter. That means it can capture 99.95% of those particles above (and below) 0.3 microns!

How often should I change the HEPA?

We tested a HEPA in real Beijing air for 200 days to get a sense of how long HEPAs last in real Beijing air. Based on that data, Paddy estimated the HEPA lifespan for the Blasts. These estimates for the Blasts are for 8 hours of use every day. If you use it more or less, you can calculate lifespan using the total number of hours below.

Time to change the HEPA?

You’ll only need to change it every 7-20 months, but we still tried to keep things simple.

Can I wash a dirty HEPA filter?

Unfortunately not. We ran experiments to test this and found that washing HEPA filters does not prolong their lifespan.