Blowers on my 2x8

[Brad W Wi]

I'm thinking of putting a blower(s) on my Dallaire 2x8. I don't know diddly about them nor have I ever seen one. I'd like to increase the output of my unit. Do I need air tight doors, vairiable speed, where would it be mounted? If I'm evaporating 43GPH right now what would could I expect? I'll stop with those questions for now as I'm sure I'll have more. Thanks for the help./

[Brent]

You can get more than enough air to increase you performance without an air tight door, but your stack will need to be well sized. From what I saw this year with an airtight Inferno arch that I ran this season, you can get better performance with an airtight and really big blower, but I need to do more playing around with air over the fire to be sure that this is really needed.

Last year I ran a 2 x 8 with an extremely simple air over fire system, and got enough air under the fire by natural draft. It made quite a huge difference in the wood burned and increase the evap rate some, but I was playing with different concentration levels to get good numbers. I could fire without turning the blower down.

If you're trying to really blast it ... no question, you'll need airtight. That means airtight bottom under the grates, sealing the draft door, sealing all the joints down both sides and around the back plate for the stack. I didn't pay much attention to how I put the rear castings on at the base of the stack and the Inferno was blowing sparks out the leaks.

There's lots of opinions on this, a couple of authoritative sounding papers written, but those papers tell you what to do with no hint of what they tried that didn't work or what they would have tried next. The only thing that seems conclusive is that you need much more air blowing down into the fire, with some pressure, than up through the grates.

There's lots of threads on this ... it will take you hours to follow them. Have fun.