If you're interested in heating a space for not much money, ie bit's of dead wood etc., check out, Rocket stoves or rocket heaters or rocket mass heaters on youtube. I reckon it's a good solution for greenhouses in cooler climates... Make sure you watch them and understand how they work. It's genius!
I've got my rocket mass heater - I used cinder blocks and stuff rather than cob. I really should put that video up on youtube...
I'm also going to use a solar air and water heater this winter. Since I have a low polytunnel, I can possibly get about as many BTUs from my solar heater as I get in solar gain to the greenhouse itself. I look forward to posting my results.
I too am looking forward to getting some stats from this year's heating season. I've been cutting and stacking wood and will get a fairly accurate reading on how much material I'll burn.
have you calc'ed how much compost would be needed to keep temp up? I suspect that it would be prohibitive to being practical... just thinking
Matthew Smith said:
Another interesting heat source for winter is to build a compost pile inside the greenhouse that is at least one cubic yard in size. They release quite a bit of heat and CO2 for the plants. The internal temperature can easily reach 160 degrees F. It is a nice way to create a nice steady heat that you don't have to go stoke all night long.
For the rocket stove you are going to want to add plenty of thermal mass around it to store the heat and not in the form of water. We tried a similar idea with a hot tube in a greenhouse in northern wisconsin. Not only did we have to keep the fire stoked all night long but we had so much condensation on the glass that it kind of defeated the purpose of it all.
I've also heard of people keeping small animals like rabbits and chickens in the greenhouse. Those little guys release quite a few BTU's and all you have to do is feed them greens from your aquaponic system!
Don't let the chickens into the compost pile though because they'll disperse the pile all over the place and all its heat along with it.
I want to hire someone to build a rocket stove heater in my greenhouse. I might be able to set up a class like environment so you can make some extra $ with class fees. I'm in northern New Mexico, off grid. Let me know if you're interested in building heater in my greenhouse!
I have been enjoying lurking around this discussion immensely.
I started designing wood gasification stoves back in the 70's because I couldn't afford an Ashley which was the stove of that time. Basically the Ashley was a tin box but it had a bi-metallic coil thermostat and that made it way ahead of the curve, as it would shut down and control the burn on it's own which was a big safety factor.
I started reading everything I could get my hands on (oh for the internet back then) and came to realize that Ben Franklin was a wood burning genius with many patents that he gave to the world for free and most modern gasification wood stoves are based upon his work even though they never give him credit. Well I will and I designed my home made stoves based upon his work and I have sold plans all over the world. The Rocket stove is based upon the exact principles old Ben came up with. Once you understand those concepts you can have a ball designing your own stove and make it from cheap scrap items. My design heats the water as well as the air and holds a good 12 hrs of wood at one time.
Vlad made one from my plans and a slide show of my latest GH heater design and he loves it. He grasped the concept and made his from what he had available in Serbia as have others in GB and India, etc. Here are a couple of pics of mine and his and an interior shot of the gas burner chamber as well as the ss water coil in mine:
I now use a blower and thermostat rather than the bi-metallic coil t-stat of old. Works fantastic. My blower came out of an old dishwasher and Vlad is using a hair dryer for now. I haven't done a write up on the GH heater yet but I can supply 60 still shots which are on Youtube under "fiskfarm" if you are interested in building one as well as my original set of plans on Ebay under "fiskfarm store" as well.
Hope this helps. Lots more photos at Vlad's page as well as mine. Just click on my avatar.
Has anyone tried one of these sawdust burning styles?