Energy Efficient Heating - Smokeless BTUs from Wood and Water

Posted by William Lehman

December 12, 2007

A friend of mine, Tom recently told me about his heating system whereby he heats two greenhouses, a large 3 car garage and a 3000+ sq ft home on about $11 a month and still doesn’t freeze his butt off…

So instead of just writing it all down and trying to explain it, I asked Tom if he might be willing to show off his system to the world. Here are some rough facts to consider.

2000 gallon water tank with wood-burning chamber(s).
170 foot of hose to the house and another 170 foot back to the return inlet in the tank.
70 foot to the greenhouses and 70 foot back to the return inlet in the tank.
1 load of wood burns clean and heats for a day (depending on the type of wood).

This first video mainly looks at the general construction of the tank and fan mechanism that pulls the air through the burn chamber and pushes it through the floo pipe. Next video addresses a little more information about the fan and the temperatures and some stats about the boiler. Note the outgoing temperature and the incoming temperature to get an idea of the efficiency of this type of heating.

Next we look at the distance this water travels and where it goes to actually heat the home and greenhouses.

Now Tom also uses a Flat panel Heat exchanger to heat his water leading back into his standard water heater. Tom will show how this works here.

The Furnace is also rigged in such a way that when the thermostat calls for heat, it just turns on a fan which pushes air through a radiator to heat the home.

And a look at the back of the furnace.

Here we go back out to the boiler and light the thing to show it in action. This is what the upkeep generally is, mainly just cleaning out the ash and burning more wood to keep it going. Note the still glowing coals after 23 hours since last burn.

Of course, we have to load it and see how clean it actually burns.

Just a few minutes into the burn.

Let’s look at the exhaust of this system to see what is actually making it out into the atmosphere. I got a chance to hold my hands under this thing (I made Tom do it first) and was really impressed. It’s a lot like a bathroom hand dryer but with a slightly more moist feel to the air. This is important because you do not want the air to cool too quickly and condensate inside the floo pipe.