Kitchen Garden Forum

My new greenhouse is finally set up. I cant wait to fill it and start using it. Its like a big wendy house for grownups- so excited . Strange what simple things please me .Any tips on the best sort of heater to get for energy efficiency - i dont want to grow exotic stuff but do want to keep it at about 7 - 10 degrees over winter?
Seedling

Hi Seedling,
I should wait until you go to the Malvern Show 'cos you normally get heaters at a good price as a "Special Show Offers" I got a 2Kw one a couple of years ago at a reasonable price and it has behaved very well.

Dear Seedling, when you say what sort of heater, do you mean, electric, gas or paraffin.
If so i have tried them all over the years, and if you can get electric to your greenhouse, this is by far the best.

Kind regards Old Herbaceous.

Theres no fool like an old fool.

Get one like mine. Electric fan and on a thermostat. You can check it out on Saturday.

Electricity could be expensive if you
want more than frostproofing and
want to heat the whole greenhouse.
I have compromised with a very large homemade enclosure with thermostatic controlled heating cable and polystyrene foam under and bubblewrap over the top, anything delicate will stay in there over winter.
In late spring when the worst of winter is over a fan heater protects the whole house.
Remember also that under new regulations it has to be wired prfessionally, otherwise any DIY wiring will still have to be inspected as conforming to be legal. A RCD is a necessity as then it is totally safe personally.
Allan

Cheers Allan, forgot to mention the new regulations on outdoor electrics.

Kind regards Old Herbaceous.

Theres no fool like an old fool.

I've got an electric one but it's low wattage usage and not a fan type - I'm told it's the same sort of thing I use for the dog in her outside barn at night - frost free but not drying to the eyes?!

Seedling - ask Lyndon about it at Malvern if you wish.

That sounds good; I'm always having to move stuff around to stop it getting to much hot air blowing over it. I'll be talking to Lyndon too!

The subject of heaters has pricked me into asking this question.Has anybody out there in KG land managed to put together a heating system which is self sufficient using either wind or solar power for a greenhouse?

darrenc wrote:The subject of heaters has pricked me into asking this question.Has anybody out there in KG land managed to put together a heating system which is self sufficient using either wind or solar power for a greenhouse?

No, but I would be interested also if someone has.

There was a heating system put together on the BBC2 programme, It's hard to be Green (I think that was the title)
Pete

Hi Seedling,
I believe that you mentioned some time back that you didn't have room for a very big greenhouse and that really you only wanted to bring on plants for the Allotment.
Prior to me getting my greenhouse I used to make a tunnel within my larger tunnels situated on the bench tops (all benching in my tunnels) by laying 4" expanded Polystyrene sheeting on the bench then putting to hoops over that to carry the Bubble wrap.
The area was normally 12'x 6' and the heater situated in the middle suspended from the roof. I worked it out that it only cost me 17p a day them but electricity has gone up considerably since then.
The EP sheeting was raised slightly in the centre to drain any water that I used to run off either side.
In another tunnel I had a Sun Tunnel made exactly the same situated on the bench for various cuttings and a misting system.
In your new greenhouse you probably will have a small bench and that too can be partitioned with Bubble wrap to do the same thing and the cost to heat that will be very minimal.
It is essential to have a good ventilation system and the oldest fault in the book is to say I am heating that so bung up all the holes to make it draught proof. Fine for living accommodation but lethal to plants.
I have heating systems in all my tunnels and circulating fans to keep the air moving. Don't think you would like the cost of those. (£500 X 6 many years ago)
I should delay making any decisions before going to Malvern.
JB.

http://www.itsnoteasybeinggreen.org

How does the greenhouse heat sink work?
Some details are in the book, but half the adventure is working out for yourself and thereby customising you solution. All you need is:

The heat sink is imploded glass - we used bottles from various parties and the local pub - imploded courtesy of Krysteline www.krysteline.net
Big hole - we lined it with polystyrene that came as packaging
Pipes were standard waste pipes for under sinks etc
Fan was a small 12V computer fan from a market £1.20 - in a box made of scrap wood
A 12V deep cycle leisure battery
Small 11w solar panel and charge controller
Old chimney cowl for the air to be pushed out the glass

Air sucked down from the apex heats the broken glass under the floor. Fan runs 24 hours a day. As the greenhouse cools the cooler air is still pumped through the glass, but when it comes out through the cowl, at floor level, the glass has warmed it so a constant supply of warm air is now being pumped through.

Dear Belinda, forgive my ignorance but is the heat sink totally independant of the mains supply?

Seedling

I'm just catching up with the Forum now that it is darker in the evenings and I have a bit more time. Lots of good advice above. I got a new greenhouse (12 by 10)about 15 months ago. The 3 KW Parsene electric heater kept things frost free last winter. In addition I made a heated bed with a soil warming cable with one of those cold frames made from wood and polycarbonate sheets (all the garden centres have them for £40 pounds or so) The systems worked well except for the bed which overheated in the early Spring - the next task is to control it with a thermostat as Allan suggests. In mid Spring I removed the frame and used it as a conventional cold frame outside. (I have tried paraffin in the past - Parsene Big Red - and it was rubbish - stick to electricity)

Have a good winter

Chris