[Snoop]

Thanks, shedmeister. Having read your reply, I remain sceptical your set-up would heat a greenhouse to a useful temperature or for sufficient time. Shame though, as I was hoping to be proved wrong.

[Max4]

I had considered wind power, our site is on a hill and is generally windy. The pluses would be consistent power without reliance on the sun but I'm concerned about the maintenance factor. I'll admit that I don't have a lot of experience but generally anything with moving parts is going to need fixing/replacing every so often. Also its a lot more intrusive so I'm not sure what the reaction of the other plot holders would be.

The other option I'm considering is putting the paraffin heater in a small house alongside the GH then piping the hot air through and venting outside. Would need to keep an eye on the soot to make sure it doesn't buildup too much.

Anyone any thoughts/experience on either option. Luckily its warmed up so I have the luxury of time to get a solution in place for next year.

[grendel]

I seem to remember that old fashioned greenhouses were built onto south facing walls (the wall acts as a thermal trap - holding the heat, some had a hot air system which was basically a fireplace on the end wall with the flues running along under the floor (or at least under the raised growing benches). the fire was lit at nightfall and once again the flues held the heat for the remainder of the night after the fire died back.