Forced Air Fan

[danno]

I've got a squirrel cage 550 CFM fan - but I'm looking for bigger, like 850-1000. Anybody know a good place to find new or used cheap fans - or anybody looking to make a trade for a 550.

The 550 works fine if mounted directly behind the arch - but I prefer to have it outside running through 20' of duct. Allot quieter. Anyway, the 550 just would not push enough from 20' away. Also, I'm thinking of adding some pipe to run air over the top of the fire as well.

[lpakiz]

I'm not sure of the CFM, but every old gas or fuel oil furnace has one of those squirrel cage blowers inside. The metal salvage yards would have them by the dozen.

[CityMaple]

The issue that you have going through 20' of duct is the air resistance, same thing happens in furnace ductwork. ways to overcome this 1) bigger duct, means less pressure the blower has to build up so more air delivery, i am looking at a pressure loss chart and looks like you should have about an 18" diameter duct to handle 500 cfm with low friction loss. if you are using square duct you have to calculate the square inches of the circle/oval that will fit in the duct because the area outside that space dosnt have very good air moving capacities. 2) higher cfm fan will have a bigger motor on it so really all you are doing is overcomming the duct restriction with a higher pressure. If you are going to look for a furnace fan go with a direct drive that are on most newer furnaces, they deliver alot more air9at better pressures) than the old belt drive fans, also usually have multi speed motors on them.

[Haynes Forest Products]

I would bring a bottle of syrup as a calling card over to the local heating contractor and ask him about the scrap pile and if he would let you pull a blower out of one. Most contracters install new furnaces and dont want the old ones. When a contractor goes and gets a new furnace they dump the old one at the wholsale outlet and they are snatched up by the scrap hounds making thair rounds every few hours. I have this theory that if you get one of anything (and i dont care how) you will end up with another one very soon afterwards free or better than the last one. When you get into the scrapping for parts to support your habbit its like drugs everyone will find out and you will have like minded people helping you out. Have Fun.

[markct]

my 2 by 8 arch has two oil furnace burners that i gutted out the nozzle and everything so its just the squirell cage blower, they are a pretty good sized blower if ya get a larger burner. i havent fired it yet tho so im not certain its right!

[OGDENS SUGAR BUSH]

haynes is right about finding the first 1 of anything the 2nd comes much easier

RICH

[WESTVIRGINIAMAPLER]

Ebay is a good place to pick up one. Not sure why noise is so much of an issue. I have a Dayton squirrel cage and it is a 745 or 760 cfm and I run it wide open except when firing and it doesn't make much noise. Get a high pressure blower and mount it outside and pipe size and friction won't matter.

Ryan(Breezy Lane) has similar setup and has some pics on his weblink.