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Greenhouse Heating


I am wanting to purchase a heater for my greenhouse 6' x 4' its aluminium and polycarbonate. I'm not really keen on the paraffin heaters as I have a 3 year old son. I have seen online the tubular heaters but are they any good? If so what size would be best?

I'm wanting my grape vine to finally produce grapes this year and just can never get it warm enough thanks to our great British weather!




  • Plant itPlant it Posts: 155

    I have a small generator and a mate of mine adapted it to work a small tubular heater.

  • Woo2Woo2 Posts: 223
    I also have a greenhouse which I want to heat but am unable to get electricity to it at the moment. I was thinking of buying a paraffin heater. I'm a novice gardener so unsure what to buy, any advice or tips gratefully received. Any cons with a paraffin heater? Also what temp do you usually try to keep the greenhouse at? Are heaters kept on constantly until the warmer weather?
  • I really can't believe no one has come up with a suitable "green" solution for greenhouse heating. 

    Solar i get, it would only work during the day when the greenhouse is "heated" anyway.

    However you'd think you could charge some kind of battery during the day to run a small tubular heater off during the night.

    Then again wind would seem the most obvious, if you can get a small wind turbine to run the leccy in a caravan you'd have thought someone would have made one for a greenhouse heater, must be an obvious reason why no one has done this but i don't see it!

  • Ryan LloydRyan Lloyd Posts: 391

    This wouldnt solve your dilemma, but may help. Try putting a layer of bubble wrap in you greenhouse (which is what I did last year), then it retains the heat from the daytime much better than usual. Thats the greenest way I can think of, but may only raise the temperature by 5 degrees or so image

  • artjakartjak Posts: 4,167

    On another thread someone suggested 'can furnace'. If you google this you will get to an inventors blog which tells you exactly how to make it. The principle is; lots of aluminium cans painted black, stacked inside a box covered in glass or plastic. Cold air enters at the base and travels up through the cans which have holes at both ends, and exits at the top as warm air, through a hose into the G/himage

  • PalaisglidePalaisglide Posts: 3,414

    As an old gardener always had a greenhouse and tried them all nothing will give you more than a frost guard.
    Paraffin is costly gives off moisture and needs constant attention if you do not wish to find all your glass black with smoke.
    A gas heater costly gives off some moisture although will not be as bad as Paraffin.
    None of those will ever pay their way, while you are eating your £1 per carrot salad the shops will be selling them by the bag full.
    My Father built a stove to burn rubbish outside the greenhouse with large pipes running through it worked well and cost nothing H&S plus green laws would frown on that now.
    I have a South Facing Wall Mounted GH now and ran electricity to it. The wall on even sunless days takes in heat and gives it back at night.
    A Sand-bed with warming cables and thermostat with shelving above allows for seeds to be sown and then put on the shelves with a bubble wrap curtain around that section, add a Fan Heater with Frost guard and that does nicely.
    Saying all that over the last three months here in the Northeast none of them have been switched on yet and will not be until we have more light, very important and the outside temperature raises above freezing, at the moment it is minus 2.
    You will do your own thing and find the cost prohibitive depending where you live I would say let nature do it naturally.


  • Woo2Woo2 Posts: 223
    Thanks for the info Frank, much appreciated
  • Jazzy2Jazzy2 Posts: 36

    I have a very old stove which burns scrap wood in the day (needs constant attention otherwise goes out, and a few bits of coal to keep it going thro the night).

    The chimney is vented to the outside,minimal cost, maximum return.

    A safety guard is necessary to safeguard young children.
  • My greenhouse base is of 3"x2" paving slabs, they warm up during the day through natural radiation. (Keep your glass clean for maximum effect) I have not recorded specific tempereturs but it is noticably warmer inside when entering in the morning.

    Starting my early seedlings I have an plastic box with water in it and insulation round the outside. using a 100 watt thermostaically controlled fish tank heater keeping the water warm. The top has a plasic lid with small holes drilled it. I place my seedling trays on this lid and cover the whole thing with a home made mini greenhouse, this keeps the warmth and humidity up at minimum cost. I have for the past four weeks had this in operation for the past four weeks during the feezing March weather. The tempereture inside the mini greenhouse is kept at 60F.My Tomatoes and Lettuce love it. Checkout the picture.



  • gurbiangurbian Posts: 10

    i'm hoping to have a new greenhouse in the next couple of months and intend building a 'rocket mass heater'. They seem to work for not much money and theres loads of info available online

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