furnace blower

[Bricklayer]

I keep seeing these type blowers on kijiji in my area, and don't have a CFM rating I them only this info. I am looking for a blower for AUF for my 2x5 arch.

Fasco 7021107102
Type: U21B
115V 2.3A
60Hz / 3400RPM

[Bucket Head]

That looks like a high pressure blower to me. You don't need the high pressure type for air under fire forced draft. A "squirrel cage" type blower is what you want for your application.
The H. P. ones make quite a bit of noise too. That's why most plumb them from elsewhere in the sugarhouse. The cage type are quieter and are usually located close to the arch.

[Bricklayer]

Is there a way to tell how many CFM the blower is? What CFM is needed for a 2x5? I eventually want to add AOF to the arch but not this year. Just figured if I could get a good deal on a blower at least have it.

[Woody77]

Hey I have used several type's of blowers all acquired free from one source or another.I used that style for two seasons wired to a dimmer switch to adjust air flow.it worked just fine but is loud .they are thrown away by hvac companys & plumbers every day and most of them will trade a little bottel of syrup for one .

[BreezyHill]

That is a good sized blower. I would give it a try.

I have a 2x6 and I use two outside wood boiler fans. One is a 70 cfm and the other is a 100 cfm. I piggy back them together to force the 100 thru the 70 since the 100 will not bolt onto the plenum. I have no problems with the two except for when pulling off syrup from time to time. So I have a switch on my DIY auto draw off that allows me to kill the power to the fans. My variable speed is on the other side of the rig and I often don't touch it at all.

I have another much larger fan for this season that will need a flow adjustment device, it was an exhaust fan for trucks in a garage. 8" pipe was used over the stack on the big trucks.

[Bricklayer]

if I used this blower for auf would I have to build a manifold for it or could I just blow it in back of arch under the grates?

[Woody77]

I have a 2×5 oil barrel arch that I used my power vent on . the fire box end is 24"×24" and I had plenty of air almost to much at times.being theit designed to hook up to scedual 40 2" PVC pipe I used a 2" iron pipe flange the kind used most often to hook a hand rail to a wall or post with the 4 bolt holes in it .I used a hole saw to cut through arch and fastened it to the bottem of the fire box.I glued a male threded end on the PVC on the fan and threded it together it worked great. Good luck.

[Bricklayer]

How do you tell a hp blower from a regular blower. Is there a certain rpm or CFM rating? There are a ton of cheap blowers on kijiji right now.

[wiam]

Low pressure would be like a squirrel cage blower. Looks like a gerbil could run around inside. High pressure will look similar to the picture posted earlier in this thread.

[BreezyHill]

HP blowers look like a paddle blower or a paddle boats drive wheel, the other is as Wiam said.