[GBlist] wood stoves and air intake in tight homes

[Chris Koehn <chris@koehn.com>]

We have a Rais "Mino" in our carriage house, which is one of the tightest,
most energy efficient structures in Wisconsin. We have a geo thermal ground
loop, and do not use an air to air heat exchanger (preferring in our case to
mechanically exhaust air, and bring fresh air directly in to the air
handler). 

Rais does not make it particularly easy to provide outside air for
combustion on the Mino. There is no "knock out"- a custom manifold must be
built to encourage outside air toward the intake on the bottom of the stove.

We went 9 rounds with Nels Wittus (of Rais & Wittus- the sole U.S. importer)
over whether or not outside combustion air is required. The end analysis is
that we can generally get away without it, but we can't run the bath fan or
kitchen exhaust while the stove is burning without back drafting it. Also
during start up it is very helpful to open a window, to allow the stove to
more efficiently get a draft started.

While I LOVE our Rais stove (we can heat our 1100 sq ft structure for 24
hours with 750 cu in. of oak..) I probably would not choose it to b a
primary heat source, as makeup air IS necessary in a tight structure for
efficient operation, and the Mino doesn't make this easy. My understanding
is that other Rais models are easier. As a secondary heat source, and for
ambience, it's top notch.

Hope this helps,

Chris 

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