An external combustion engine. Or a no-combustion engine, powered by the
heat from the sun, or in my case, from the heat of the network switch it is
sitting on, or the wood stove in the living room.
The MM-6 Stirling Engine
by American Stirling
This gadget is just amazing.
I have had it sitting on a slightly warm ethernet
switch in my office for over a year now, and it just
keeps silently running.
It will run using only the heat from my hands.
The parts are beautifully machined and precise, and
the piston slides in and out of the glass
cylinder making no noise, but fitting tightly enough
that air does not get past it.
The Heat Wave Wood Stove Fan
by Thermal Engine Corporation
When you want to move the hot air from the wood stove
around the house, what better way than to use a Stirling
Engine powered by the heat from the stove?
This little engine really moves, and moves 300 cubic feet of air
per minute. It is quite robust, made of heavy gauge welded steel,
aluminum and brass, and stands up to abuse, although it doesn't get much
abuse sitting on top of the wood stove. We have played with it on
a gas range that gets much hotter than the wood stove, and besides the
steel getting a nice blue color, no damage was incurred.
We don't let our wood stove get above about 500 degrees Fahrenheit,
for safety reasons, but this little gadget can easily take twice that.
And since it moves the air around near the stove, it helps to keep the
stove cooler and the room warmer at the same time.
It works well, does a useful job, and is a great conversation piece.
And it uses no energy except the heat from the wood stove.
You can buy Peltier-junction thermoelectric generators with a motor
and fan that are made for the same purpose (moving the hot air from
the stove into the room), but ours lasted only about a year before the
Peltier junction became intermittent, and the fan stopped working.
The Stirling engine in the Heat Wave has had no such problems -- it is
built like a tank.