Topic: gas, paraffin, wood, smoke less coal ?? - the best way to heat a greenhouse?

[gazzaroo]

iv been looking at ways to heat a greenhouse on an allotment.....
id like to grow all year round,we have a 50ft long greenhouse made up from old windows and secondhand greenhouses,.. am working on a 12v solar and battery power for lighting  at night . i was planing to make and potbelly fire from old gas bottle and using 12v fans to blow hot air from fire around the greenhouse, what you all think.

 

 

[RobinOfTheHood]

I think you'll need a lot of solar panels for 50ft of lighting. Like the idea of the fans, although I reckon it won't be much of an improvement on natural convection from the stove.

[daveyboi]

You do not say what sort of temperature you are wanting to maintain whether it is just frost protection or warmer.

I personally would not try to heat such a large greenhouse as the fuel cost would be excessive.

Rather I would section of a part of it for a warmer environment.

[chriscross1966]

Hot water tank from a skip or find something to use as one. Wood-burner burner built out of a old gas bottle, small pump from wherever, ditto some thermostats, old rad from skip..... then you can heat it with pallets.... Also system would be amenable to attaching a homemade solar thermal panel made from old radiator (skip) in wood frame with a piece of recycled glass in front of it...that would harvest heat during spring and autumn and put off having to light the stove.... cos at that time of year the cold nights are generally proceded by sunny days....

[Ellen K]

If I were trying it, I would go down the route of insulating the GH (with bubble wrap and any other translucent material you can find) and using a simple heating system like a woodburner.

But wot Davey said - it's a massive volume to heat.

A neighbour on the plot has a 10 by 12 ft plastic GH - which has taken massive weathering over the last 2 years - and they have wrapped it in bubblewrap (on the outside).  It has been surprisingly effective at both holding it together and keeping it warm.

[davyw1]

My heating is solid fuel Parkray fire which are designed purely to heat water. I have 22 mill piping all round the perimeter leading to a reservoir made out of a large gas bottle two pipes 4" apart the top taking the hot water to the reservoir a second pipe below returning the cooler water to the fire, no pump just the force of the hot water expanding and works a treat BUT my fuel is free so i can afford to run it.
A wood burner would not last the night so is pointless
Pot belly stoves or blacksmith made fires throw out a lot of heat but not enough to heat a GH your size and and again will they last the night if they don't last the night the fans will then be distributing cold air.
No mater which way you go it will be virtually impossible to heat a GH that size.

Your best bet would be to partition it off into three, one area a small hot house where you can have a system of germinating your seeds and raising the small plants till the they can be moved into a cooler area with a temperature of above 45/50 deg then a large growing area where they can be hardened off before going out to harden off again.

[Ru1]

I agree with daveyboi.  You will need to section off a warmer area.  If you don't then whatever you are using to heat it will cost a fortune.

[gazzaroo]

its ar 3rd year with the plot  and getting some heating and 12v power system in befor next winter ..we have be trying to make a hot water heating system using the heat from compost heap. but still working  that one out ,,putting a radiator on roof with piping and a header tank see some thing like ,good thinking i can do that in one green house,, we going to try a bigger compost heap with more piping rolled in side...using a tap to control the flow and try to keep warm water moving. am a the look out for an old made up  system  for sale.,,