2 ms·

So why doesn’t someone sell air purifiers that take furnace filters?

• sbierwagen 6y ago
  That could work as some kind of open source hardware project, like OP, but I don't know if you'd make a lot of money with something whose competition is a box fan and some duct tape.
  • spoonjim 6y ago
    But surely the Shenzhen guys selling $20 box fans at Walmart could get $25 for them if they had 25 cent clips for filters?