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19 messages
07/04/2013 at 11:59

What are the best ways to heat  a greenhouse?

07/04/2013 at 12:19

Using the sun is the best way but no use during winter. Having the greenhouse in full sun and dug about 1 metre into the ground surrounded by stone chippings, having the floor tiled all retain heat and use the earths heat. A thermostatic fan heater will then keep the heat around the greenhouse.

07/04/2013 at 12:30

Another good way is using massive rolls of horticutural bubble wrap around the walls. I have seen it in B&Q for £15, not sure the length though. But if stored correctly, it could be a worth while investment especially when used year are year.

I have to use parrafin as we don't have electricity at the allotment, but a 5ltr container lasts all week - it's £1 a ltr.

07/04/2013 at 20:57

marshmello, where are you managing to get paraffin that cheaply? I'm having to pay B&Q £7.00 for 4 litres.

07/04/2013 at 21:29
blairs wrote (see)

Using the sun is the best way but no use during winter. Having the greenhouse in full sun and dug about 1 metre into the ground surrounded by stone chippings, having the floor tiled all retain heat and use the earths heat. A thermostatic fan heater will then keep the heat around the greenhouse.

Blairs, could you give a little more info 'dug about 1m into the ground surrounded by stone chippings'.  At the moment I'm visulising a sunken greenhouse!  Can't think thats what you mean.  Only ask as I am getting a greenhouse this year and am trying to gather as much info as pos so I get the right base laid.  Thanks.

07/04/2013 at 21:34

Artjak, I buy it from the Allotment Association Shop on site - a not for profit organisation which is run by a few of the gardeners.

Yes, it can be quite expensive from places like that.

07/04/2013 at 22:42

I have made myself a propigation bed with heated cables that warm the soil and are controlled by a thermostat, that really helps keep my greenhouse warm.

07/04/2013 at 23:37

I'm using grass,no not smoking it but bags full of clippings as they break down they give off a lot of heat. It's enough to keep the frost at bay overnight. Along with fleece and a few black milk cartons. which are warmed by the sun and release the heat at night as it cools.

I'm thinking about buying a sidney tube to effectively harvest the suns heat. A single tube is about €65 http://www.solarbook.ie/sydney-vacuum-tube.html

The link explains better than i can.

08/04/2013 at 09:54
LorraineP wrote (see)
blairs wrote (see)

Using the sun is the best way but no use during winter. Having the greenhouse in full sun and dug about 1 metre into the ground surrounded by stone chippings, having the floor tiled all retain heat and use the earths heat. A thermostatic fan heater will then keep the heat around the greenhouse.

Blairs, could you give a little more info 'dug about 1m into the ground surrounded by stone chippings'.  At the moment I'm visulising a sunken greenhouse!  Can't think thats what you mean.  Only ask as I am getting a greenhouse this year and am trying to gather as much info as pos so I get the right base laid.  Thanks.


Until recently all greenhouses were built into the ground - at least 1 metre with a trench around them. You only really had a top few feet of glass. Frost only penetrates  the top 3 inches and the earth naturally keeps plants above freezing point. If you put stone chippings around the greenhouse (they were built with brick foundations) then that is a heat sink as the stones retain heat. You could make the greenhouse warmer by using hot beds - grass clippings as blackest has said. It takes a bit of work though!

The bog standard glass greenhouses loose heat as it escapes out very easily. Have a brick foundation and it looses less heat and the brick retains heat. I would also always have a stone/paved floor in a greenhouse. Earth is no use.

08/04/2013 at 10:06

Blairs: so I wasn't so silly about a sunken greenhouse then?  

If it has a solid floor will it need drainage?

 

08/04/2013 at 15:27

Re drainage, you would need to site it somewhere where it does not flood and water naturally flows away. Bottom of a slope is no good!

I found this link:

http://www.tulipsinthewoods.com/plant-care/cheap-and-easy-greenhouse/

08/04/2013 at 15:37

I have been trying for ages to find a method of using used sunflower cooking oil for heating my greenhouse either on its own or mixing it with say parrafin for instance but to no avail.

 

Anybody got any ideas/info on the subject please

08/04/2013 at 16:14

not seen anything affordable for sale, did find this

http://wasteoilheaterforum.com/index.php?topic=72.0

There  seems to be a few technical challenges one being the ash problem. Seems you would be making a central heating system for your greenhouse. I think the costs of the system are going to blow away the economys of using waste oil. On a commercial scale it could get interesting but not for one man and his small greenhouse.

 

08/04/2013 at 19:37

Thanks for the info blairs, not sure this would work for me. The area where I was thinking of putting the greenhouse can get quite soggy in winter.  Will look into it further though as I like idea. 

08/04/2013 at 20:52
Greentooth. What are the running costs like for those soil warming cables. Cheers
08/04/2013 at 23:20

I'm really interested in how others are heating their greenhouses, especially anything thats low cost - i've just bought my first greenhouse and want to keep using it over the winter if possible.

The greenhouse will be on a slab bed and i intend to install a solar heat sink - saw it on "It's not easy being green" a few years ago and the idea stuck with me - http://www.reuk.co.uk/Solar-Greenhouse-Heat-Sink.htm

i'm hoping that i can generate enough electricity in the winter from the solar panel to run a small heater and the switch to the fan option in summer (and maybe even run a small electric propogator).

I'd be interested to hear if anyone has tried/been sucessful sing this method.

Thanks

08/04/2013 at 23:56

My low-tech approach is to have lots of 2l plastic pop bottles filled with dark liquid - comfrey feed (I make *lots* of that!) filling all gaps between pots etc around the borders of my GH.  They absorb the sun's heat really well and slowly release it at night.  It's far from perfect but does help keep the frost out at this time of the year.  The bonus is I always have liquid feed very close at hand.

09/04/2013 at 00:17

Solar power for electric heating is not going to work with a conventional heater, i was going to say not at all but then i was thinking my heated propagator is a reasonably managable 60 watts and half the time its off.  There was a link to  a video where someone was heating a shower with compost that might be a possible with a small  pump a radiator and a big pile of compost to break down. Actually maybe not a radiator but hose running through a propagator bed... sydney tubes are pretty good but still a bit short of output on a cloudy day.  maybe you could convert oil burner boiler to run on waste veg oil and pipe some of that into a greenhouse / conservatory. The plus side being that used veg oil can be aquired from free to 25 cent a litre. A quarter of the cost of regular oil. still a big investment to start with.

09/04/2013 at 05:42

It depends on temp. you need. You can use solar vacuum tubes - you can get warm water even if it's cloudy, but problems will begin in summer. Propably you don't want to boil your plants.

If you can pot your plants, then best thing so far is heating film - If you can keep roots in warm then temp. outside can be very low. You can use it under kind of growing table.

One link I found about film http://teplofilm.com/

And if you don't need second half from your greenhouse during winter , then you can divide it using polycarbonate sheet or bubble wrap

 

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