"Greg O" writes:


"Peter Wells" wrote in message
.. .
Thanks to all who replied, a lot of good advice; I'm going to search
around for some cheap filters and get after it.

Peter


Don't search too hard, any 2" pleated paper filter you can find at Menards
should do.
Greg

I'd agree. My air cleaner has a standard pleated furnace filter for
the fine collection, and a [cut with a utility knife] standard washable
fibreglass furnace filter for the coarse filtration. About $5 for the
fancy one; $2-3 ea. for the coarse ones.

The design process was:

- decide how big a box I needed to hold the furnace blower, and how to
mount the blower so that its output was all directed outside the box and
it could suck air from the other end of the box. (It's bolted to one end,
with a standard HVAC grill covering the hole.) I made the box using pieces
of broken wooden hockey sticks for framing and MDF (probably 3/8") to form
the sides, top, bottom, etc. You could probably use cheap plywood and skip
a frame. I used scraps I had on hand.
- decide how to mount the largest common fine filter size I could fit
in that box, so that the fan had to suck air through it.
- leave the other end open, with enough bits of wood glued on to form a
slot I can stick the coarse filter in.
- find a spot to mount an electrical box for the switches. I used one
of those plastic boxes with the foam covers that are supposed to seal
against vapour loss on exterior wall, so that dust wouldn't get into the
box from inside the air cleaner. (The electrical box is mounted inside the
air cleaner. You could moutn it outside to avoid all that.) I used an
extension cord with the end cut off to give me my wiring to plug into the
wall.

That's about it. Crude, quick, easy, and after about 10 years I've had
no urge to change it.