How can I keep an off-grid polytunnel heated?

Discussion in 'Holistic Farming' started by Stuart J, Sep 5, 2017.

  1. Stuart J

    Stuart J Member

    Will a solar trickle charger keep a battery full running some sort of fan heater?

    Any other ideas?
  2. JWL

    JWL Member

    How about running a waterpipe through a muck or compost heap?
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  3. KMA

    KMA Member

    Really depends on the size of the polytunnel and what temperature you want to be sitting at.

    I'm playing with the idea of creating a small hotbed in the greenhouse and definitely going to build some cold frames to place on top of the new hotbeds I plan to build in Jan/Feb.

    I completed the last hotbed in mid June and it's still sitting at around 23c, which is around 10c more than the normal background soil temp. Very quick and easy to build.
  4. Daniel

    Daniel Member

    A diesel fired heater hooked to a thermostat and ignited by a battery topped off from a solar panel would be best i should think.

    A solar array big enough to capture enough energy in winter to run an electric heater wouldnt be cost effective.
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  5. JWL

    JWL Member

    Plenty of lorry night heaters on the bay of fleas that use very little diesel but can put out a great deal of heat. It's the initial start up that kills the battery, once running they use very little battery power
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  6. llamedos

    llamedos New Member

    This, if you can get any rape straw based bedding, from stables, the amount of heat generated by this is quite amazing, and once rotted which it does very quickly it makes amazing fine crumbly compost.
  7. phillipe

    phillipe Member

    You really are pee in in the wind trying to keep a uninsulated draughty poly tunnel warm ,just try to keep small areas warm ,is your best bet
  8. Clive

    Clive Staff Member

    Georgian and Victorian pineapple houses were heated by pipes running through FYM
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  9. Deutzdx3

    Deutzdx3 Member

    Waste oil heater. We manufacture them and run 3 of them in our workshops, parents house. We have 4 in green houses locally in place of their water heating for frost protection.
  10. Kidds

    Kidds Member

    No it won't.
    You need to be burning something if you want a heater, diesel, wood, coal etc. But be aware that the fumes from fossil fuels will likely kill your plants or at least the sulphur in them will.
    Are you trying to heat it or just keep the frost off?
  11. mo!

    mo! Member

    Double up your poly tunnel, one inside the other. I'm sure Bob Flowerdew off R4 Gardeners Question Time grow pineapples in his...
  12. mo!

    mo! Member

    And use a wood burning stove. Stack bricks around it to store heat for a slow release over two days.
  13. Eat mcdonalds, stand in poly tunnel...the rest is history..

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  14. Deutzdx3

    Deutzdx3 Member

  15. renewablejohn

    renewablejohn Member

    Heat our 40 mtr polytunnels with a sawdust burner made from 2 x 40 gallon drums and an industrial air filter.
  16. As I recall, tomato houses in teh UK, pre-european imports of Toms from Spain and Holland used to pump the fumes into the glasshouses to allow the plants to utilise the CO2
  17. Kidds

    Kidds Member

    They still do but not if there is sulphur in them.
    What they are doing is trying to increase CO2 levels, plants grow better with more CO2 (within limits)
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  18. A1an

    A1an Member

    Paraffin green house heater?
  19. onodle

    onodle New Member

    I built a wind turbine that charged a 12v leisure battery, from that the battery powered a 12v water pump and 12v water heater. I ran water pipes under the beds placed on a bed of rock and built up from that. It keeps the soil warm and that's all you need really.

    If you want to insulate inside I always add additional crop tunnels like a custom low tunnel / Caterpillar tunnel so the plastic is doubled.

    My foot ways are slabs to help retain and release heat.

    Doing the old straw and manure is great as a hot bed works well BUT you get some flies in and it's game over. I walked into my tunnel thinking it was raining looked up to see about 1,000,000 along the top took ages to get rid of them as well.

    If you want to go down the hot bed route id build straw bails walls, place about 2ft of fresh manure inside that and then a layer of compost on top and then add some clear plastic for the roof, will insulate and you will get around 6 weeks of heat form it in the winter before thermal mass is lost, once used it can all go on the garden. The starting temp of our hot bed was around 46c and cooled to 12c after 5 weeks.
  20. KMA

    KMA Member

    The recommended way for hotbeds is to dig over the soil/straw for a couple of weeks to get thing going and build heat, FECK THAT! I'm quite happy with temps in the low to mid 20s and so are the veg.

    This is my latest hot bed completed 15 June the soil is still sitting at a steady 22c, - thin layer of soil, layer of haylage bales then 8" soil on top, over the season it has needed topped up with soil/compost as the bales break down, generally when I earth up or harvest the crop.

    Attached Files:

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