Goodness, Bill, I hope it and you and your plants are safe! It's going to take a lot of fuel to keep it going, and in that sort of space I would have thought it would overheat everything. At the very least you are going to be feeding it 24/7, or the temperature will be whizzing up and down like a yoyo. I don't think the smoke will be good for anything either, and you MUST be careful if you are going to be working in there, because there could be carbon monoxide fumes, too. Chimeneas weren't designed for heating enclosed spaces, surely? It sounds like a recipe for disaster to me.

Have to say I agree with Gattina, Chimenas were designed to sit on your patio and give warmth when the weather is cool. The smoke is a real health hazard for you and is not going to do your plants any good. What you need in your greenhouse is an electric heater, we use a small one with a frost setting over winter but I would think you'll need to have yours going most of the time so this might prove expensive. I know someone on GoY wrote about a different electric greenhouse heater but can't remember whom. Don't use paraffin as it puts moisture into the air and can cause problems with your plants.

They will be carbon monoxide gas which will kill what I use is small oil filled radiator that is cheaper than an electric greenhouse heater

Thanks Steve! I knew I'd read a different solution on GoY!

I agree with the others re the potential for producing carbon monoxide and thats apart from the cost of fuel.

If you can get electricity to your greenhouse you can consider other heat sources such as a Propagator, Soil cable and fan heaters/coolers.

There are some pictures here of my set up the only difference now to the pictures is the fan heater, I have replaced the one in the pictues for a more efficient one.

http://www.thegardenersalmanac.co.uk/Data/Greenhouse%20heating/Greenhouse%20Heating.htm

If you want any help with specifcations just shout and I will help where I can.