AUF fan - Will this work?

[Tidajo]

Rebuilding a vintage Leader 2 X 6 wood fired outdoor arch. Trying to do it on the quick and cheap.
As I'm doing the work outside, and only on weekends, I'm stuck at night during the week with thoughts of bigger is better....(insert Tim The Tool Man Taylor grunt here).

Anyway, I have this blower laying around from an old bounce house, similar to what's in the pic.

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Would this work for AUF? Controlled with dimmer switch?

If so, I have a few other questions: can someone share a design and or pics for this? This site is full of references to AUF, and recommendations for AUF, but I can't seem to find exactly what I should be doing. All I know is I need a fan, and somehow blows air under the fire...lol.

Will this be an all or nothing design? Meaning, can I run only AUF sometimes, and not always? I ask because I may not always have electric available.

thanks in advance for any advice!

[sugarmaker94]

Yes it will work, it might be a little overkill but Idk because I have never used that type before( I use a squirrel cage type) you might want a damper of some type in your duct work to slow the flow a bit. Blowers are nice, but not absolutely necessary for operation, definitely boils faster with one though

[DrTimPerkins]

AUF will definitely improve your boil rate. You will want some sort of metal duct to deliver the air. If you put that plastic housing close to the evaporator it will melt fairly quickly. Also, you may find that it cannot be controlled with a dimmer, or that it'll burn out before too long. Some motors are not able to handle being connected to a dimmer....I suspect that the motor in that unit is made to run full speed and won't deal well (in the long-term) with being ramped down...but it'll run that way for a while at least. If it can't be dimmed, just connect it to an on/off switch. Kill the motor when firing, the turn it back on again after you close the doors.

[twitch]

once you put he AUF you will drive your self crazy when you don't have it. I use a bounce house blower abput the size of the one you show there my 5 year old told me i could borrow it during maple season it works perfect

[WI Sugarpop]

We made a manifold attached to the back of the firebox with three 2" pipes that extend in below the grates. Each pipe has six 3/8" nozzles that project up between the grates. We also have AOF and that is why we have a high pressure blower that feeds both AUF and AOF. You can see in the second pic that we have ball valves to dampen some of the air. Adding the air doubled our boiling rate.




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[twitch]

WI sugarpop I like how you feed your AOF from the out side of the fire box that would make my life a lot easier. I want to add AOF but really do not want to pull the whole inside of my evaporator apart to do it. Did you run any nozzles around front and back of fire box or only on the sides. Dr. Tim how much deference if any does it make to have preheated air going over fire vs. cold air?

[maple flats]

WI sugarpop does about what I do, but my blower is outside and I use 4" pvc to bring it in under the arch. I then split it into 2 PVC pipes 3" diam. and then one feeds my AUF the other feeds the AOF, each with a valve to regulate the flow.
Tidajo, the blower you show is a high pressure by design, however it may not last long. Along with DR. Tim's thought, I'd suggest you don't use a dimmer, but inlet air damper to restrict air in as needed or connect a PVC pipe to the outlet air and use a ball valve. That one may not be big enough to feed both AUF and AOF.

[tendermason]

WI sugarpop Could you post a pic of AOF in firebox. Thanks

[WI Sugarpop]

WI sugarpop does about what I do, but my blower is outside and I use 4" pvc to bring it in under the arch. I then split it into 2 PVC pipes 3" diam. and then one feeds my AUF the other feeds the AOF, each with a valve to regulate the flow.


Dave, I do about what you do because I studied your pics on photo bucket a year ago when we built our arch. Thanks for the inspiration. Originally we were only going to have AUF but changed our minds in the middle of the project. That is why the air manifold for AOF is on the outside. Otherwise we would have had major remodeling. We only have air nozzles on the sides. It works great.

[WI Sugarpop]

WI sugarpop Could you post a pic of AOF in firebox. Thanks

I will when I find them.

[WI Sugarpop]

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WI sugarpop Could you post a pic of AOF in firebox. Thanks

Tendermason, here are some pics of our arch build for you. The air nozzles are tapped into the air manifolds on the sides. That way we can replace them easily if need be.
Sugarpop