> Oh yeah, make sure you have enough makeup air in the shop. No matter
> how well a stack draws if there isn't enough makeup air it'll
> depressurize the shop till it hits equilibrium. This isn't good.
This is a good thing to remember when installing a welding fume
exhaust. I built one from a squirrel cage blower and other junk
collected on Big Junk Day. Worked great. I was real proud.
Until the first time I used it when the forge was going and the doors
closed. Then the forge flue drew backwards to make up the air and
smoked me out in approximately no time at all. OTOH, the (baffled)
opening for the exhaust (when it isn't running) admits enough air to
let the forge flue work well when all doors are closed.
- Mike
--
Michael Spencer Nova Scotia, Canada .~.
/V\
mspencer at tallships.ca /( )\
http://home.tallships.ca/mspencer/ ^^-^^