Combustion Fan Size ?

BIG BEAM · Post by **BIG BEAM** » Sun. Jan. 18, 2009 4:53 pm

My chimney has a real good draft so I thought if I could set the baro lower it would help slow down the natural draft.Forget that,with the baro wide open AND the cleanout door wide open the draft went from .07 to .05.
Chimney is 10"x12" with a 9" thimble.It's 20 ish today and the stack temp is 225*.Yeah my chimney will suck up insects and small animals !! Maybe that's why my Hotblast works so well.
DON

BIG BEAM · Post by **BIG BEAM** » Sun. Jan. 18, 2009 5:48 pm

A lot of the smaller fans are discoutinued.The first 4 I tried were.So I got this http://www.grainger.com/Grainger/items/4C441
DON

I'll play with it next weekend.Oh boy a new toy!

BIG BEAM · Post by **BIG BEAM** » Thu. Jan. 22, 2009 8:05 pm

Got the fan yesterday and played with it .At full speed with the intake restricted about 70% the furnace ran at 650* and the stack was at 400.When I unpluged it the stack dropped to 175* quiet fast( 45 min) so the theory works.I'm making the feed restrictor adjustable this weekend but I wont have time to do the install.
DON

DOUG · Post by **DOUG** » Thu. Jan. 22, 2009 8:22 pm

That's great news. I'm impressed that it is working so well. Good job. Did it want to clinker he coal at all? At full air it probably will acted like a forge. I'm curious to find out how the restriction cover effects the performance and how well the variable rheostat works. DOUG

BIG BEAM · Post by **BIG BEAM** » Fri. Jan. 23, 2009 10:19 pm

I've been getting a lot of clinkers anyway(Superior coal) but I think thats because I keep the ash door open when I load for about 1/2 hour and then the clinkers form.

With the fan running it's only set for a 650* burn at max so I don't use anywhere near the 50 cfm the fan can produce.I didn't get the speed controller yet but it should get here next week.
DON

I restricted the air flow with a piece of tape just to test,I'll have to make one up this weekend.