Topic: green house heating

[gazzaroo]

iv just finished putting a 16f by 6f gree house up ,,and am now thinking of the heating,, my plan is to grow fruit  in there ..iv got a coal fired burner hot water boiler that i got with one of the greenhouse ,,it came with 6" pipes for water to run in and a steel water tank..    dose any one no how long the pipe can go..

[goodlife]

I hope I understood your question correctly..but we'll see...if you have enough pipe you can put it allway round the greenhouse..but normally down just one side is enough. You won't need lot of heat out put unless you are planning growing pineapples ;D
The more you have pipework to warm up more coal you are going to need heating it.
Chap near my lottie has greenhouse about same size as yours..and he's is down just one size..he manages to keep his frost free for growing flowers over winter and starting all seeds and cuttings by resting trays on warm pipe. He fills the burner twice during winter and the pipes retain enough heat to keep it warm over night with one filling and same again during day with morning filling.
But he's is bublewrap insulated through out as well.
If you put the pipe work all way round it is quite likely that you will need to stay in lottie and wait while you've had chance to burn several loads of coal to heat all that water.