Walmart, Home Depot, Lowes, Ace, most hardware stores, most wide-selection retailers (kmart, target, sears, your local version of the big grocery store such as Meijers, Albertsons, etc, etc, etc). You'll search for "box fan" or "20 box fan" and find a million of them in the US. Don't know about elsewhere, but they are almost as common in the US as lightbulbs. Here's one common brand: http://www.google.com/search?q=3Dlasko+20+box+fan Generally they are $15-25 new when not on sale, and you can get them for $10 or less on sale. -Adam On Wed, Jul 13, 2011 at 9:47 PM, V G wrote: > On Wed, Jul 13, 2011 at 9:01 PM, M. Adam Davis wrote= : > >> You don't specify compact, but you do mention furnace filters. =A0What >> I've done in the past is purchase a 20" box fan - they are usually >> very inexpensive, especially at the end of summer when stores are >> trying to clear the shelves. >> >> Then I buy the 20x20 furnace filters, and just put them on the input >> side of the fan. =A0You can buy furnace filters in varying grades to get >> the amount of air cleaning filtration you need. >> >> As long as the fan is running, the filter stays stuck to the fan, adn >> you only have to worry about when it's off. =A0You could alos attach >> aluminum u-channel, or form your own holder from ducting if you wanted >> to make it a bit more permanent. >> >> Usually they have a simple speed control that is reasonably quiet on >> the lowest setting. >> >> It's not as quiet as some fans, and it does take up 20" x 20" x 6", so >> it might not fit your needs, but I regularly use one for home projects >> that create a lot of dust, and it works well. >> >> > Thanks! That sounds like a great idea. What store would carry it? > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .