On Mon, 11 Aug 2003 00:04:55 -0500, Traves W. Coppock
wrote:

[snip]
as for air exchanger, i built mine.
get yourself a squirle cage fan motor, and mount it into a box, about
20"x12"x30". enclose all but two opposing sides, mount the blower
inside so it can exhaust out through a hole in an adjacent side to the
open sides.
build a track to hold a furnace filter, (i use the fancy 3M ones,
spendy, but cheaper than a new set of lungs)over both open ends of the
box.then, mount it to the ceiling.
i figure it changes the air in my shop about 7 times an hour, but i
have a real small shop.
[snip]

What did you use for the track? Something pre-fabbed?