Blower For 30" by 10ft arch

[n8hutch]

Picked up A used Arch Last weekend, looking at Adding Aof/Auf , I've seen some blowers around 1000cfm & 10-11 inches of pressure. Do you think that would do the job or do I need to look for something larger. Thanks Nate

[nymapleguy607]

1000 cfm seems like it would be too much air, and really hard to balance the AOF and AUF. I am running into this problem on my arch, even though I have dampers on all the incoming air I have trouble balancing the AUF and AOF. Whats happening is the AUF uses 3/4" holes for the grates while the AOF uses 1/2". The back pressure from the AOF and the AUF is causing the air to take the path of least resistance which is to the AUF making it dificult to control the combustion rate. The plan is to replace the 3/4" holes with 1/2" so everything might balance out better. Just remember with AOF the velocity and pressure out of the nozzles is more important than CFMs.

[n8hutch]

I guess I never considered that I could have too much air, I thought I could cut back the volume with valves or slow the Blower down possibly.

[n8hutch]

Any Ideas on if this would be A good amount of Air

[jrmaple]

You probably could make the 1000cfm blower work, but I also agree it is a little too big and it is hard to balance the airflow with both AOF & AUF. If you are going to be doing both or even just AUF you might want an airtight door, and make sure your arch is insulated very well. That is one of the biggest things, if you don't have it insulated well then you have a lot of heat loss and it can be a waste of wood and electricity. Something to consider is just doing AUF with two rails (forced draft) in the front of the arch running up the edge of doors, blowing air onto the fire and forcing it back. So then you will have air from under fire and then air from the front, blowing it back and you don't need to worry about having a balance. Just something to think about.

[Schiefe4]

n8hutch read this article

http://www.uvm.edu/~pmrc/Combustion.pdf

[n8hutch]

Thanks for the link. I hadn't seen that one.