Topic: Greenhouse heating

[Garden Manager]

I am wondering what heatingyou have in your greenhouses.

I have just got my first greenhouse and am wondering what is best (for a small 'house)

[sandersj89]

Richard

I started off with paraffin in my greenhouse. It was a red contraption that held about 3 litres of fuel and would burn for approx 2 days. Once I failed to trim the wick properly and it killed most of the plants in the greenhouse, they were covered in a film of black soot and the whole place stank.

Since then I laid on a main electric supply to the greenhouse, buried armoured cable. Now I have light and use an electric heater. Probably not as cheap as paraffin but more reliable and a thermostat helps control the heat levels. I keep the fan heater on the frost guard setting between now and Feb, when I start to increase the temperature level as I start to sow new crops. The fan is also useful in summer to increase air flow.

To help running costs no matter what you choose make sure you insulate the greenhouse where possible but don’t forget about the need for ventilation.

HTH

Jerry

[Mrs Ava]

Had paraffin heaters until last winter when the rather efficient Ava plumbed me in some leccy.  Now I have a thermostat controled fan heater which is excellent.  I also thoroughly insulate my greenhouse with bubblewrap and polystyrene.

I love the smell of paraffin, but did find it created lots of moisture, plus you have to remember to refill it, which is tricky if you are away for any length of time, and you have to remember to go turn it off and then relight later, and I started having trouble getting hold of paraffin!  With the leccy heater, I leave it on and forget about it.  I reakon you get a much more constant heat and better air circulation.

I guess it really depends how tender the plants are you are overwintering.  Some of mine are very tender, and would probably be better off in the conservatory, but I only have soooooo much room!  

[Garden Manager]

Thanks to thosewho replies and voted (so far  :))

I am a bit worried about using parafin, though it may be the only practical way to get heat into the GH.

I have recently had to rework my greenhouse plans you see. I originaly planned to put the 'house near the back door on part of the concrete patio. I could then easily get an electric supply set up.

However i realised at the weekend when the weather started to get much colder, that the planned site was not the best site in winter as it would stay cold for too long and need a lot of heating. It would also be in one of the hottest spots in the summer, meaning it would need carefull cooling measures.

Now my garden is on a slope so finding a nice flat spot other than right by the house is not easy. The next flattest spot is in the fruit and veg garden, so after a lot of careful thought and discussion, I have decided to have a rejig in the fruit garden. This will mean loosing/moving some summer raspberries and certainly losing a few gooseberry bushes (though I have too many anyway and are prone to mildew).

The problem with this is although it gets good all year light, it is further from the house and it would be difficult to get power out to it (water no problem though ther is a butt nearby already). So it would seem that a non electrical heating solution is required, most probably parrafin, though after reading Jerry's post i am worried about this.

[sandersj89]

Richard

My disaster was 100% my own fault, I am sure the parrafin heaters work very well, as they did for me over a number of years. One nights mess up cost me dear, hence me changing to electric.

I think they may be the best bet to begin with as it is the cheapest solution, subject to the availability of fuel. If you can find a supplier who will fill plastic bottles from a bulk tank rather than buying the stuff by the bottle you will be quids in.

Jerry

[Kerry]

i have electric-the first year i had the greenhouse i had paraffin.
without a doubt i would plump for electric again.
i find the temperature control much easier-just set the required one on the heater and leave it to it. the paraffin requires a lot more attention and i couldn't stand the smell! - how do you manage to like it, EJ?!  i could smell it as i went past the greenhouse=instant headache!
yes, initially the electric requires effort and time to set it up, we have a seperate circuit for outdoor and a buried special cable. it didn't take that long really.
also, when you have the electric out there, you can use it for lighting and propagation.
i suppose you pays your money and takes your choice!

[Mrs Ava]

Ooooo Kerry, I love the smell of creosote, tar, petrol, almonds and chanel number 5!  ;D

[Garden Manager]

also, when you have the electric out there, you can use it for lighting and propagation.

Ooh thats a good point. Shan't be able to use my heated propagator out there will I? B****R  >:(

Have to put it in the conservatory then.  ;D

They dont kick me out of the house that easily!

[tim]

Heat? In a greenhouse? OK - we have a heated bench for propagation.

Chanel No5 - that was my mother's favourite!! = Tim

[Garden Manager]

I have been doing a bit of thinking (dangerous i know!).

Our climate is pretty mild down here, temperatures dont go much below freezing even in the coldest spells. Also the plants i want to overwinter in the GH dont require heat to grow just to keep them alive. (fuschias etc)

Perhaps if i wellinsulate the greenhouse  i could get away without much heating, having say a parafin heater as backup for the coldest nights, and when I am growing from seed?

[derbex]

I love the smell of creosote, tar, petrol, almonds and chanel number 5!

Mrs D. and my mum love Chanel No. 5 -does this mean I can buy them a pint of creosote for Xmas instead? They get a spray-on tan as an added bonus!

Jeremy

[cleo]

I have parafin and gas. Wish I had electric. Gas heaters (I now think) are a total waste of time and money-they fail at the drop of a hat. I would say about £800 spent over five years excluding the cost of the gas-six different heaters and as from two days ago only one works. And yes I did keep them clean and wrapped up when not in use.

Stephan-not happy

[tim]

And to think that I was seriously considering market gardening (in the world of 'high value' foods) as a second career. As it turned out, Picture Framing was a better bet. Even if it barely paid the bills. No prob with tomato-stained fingers!! Poor Cleo. = Tim

[djbrenton]

I've got a very old set up on the allotment greenhouses, using pipework run from a coal ( smokeless ) fire. This will be my first year using it and I'm already contemplating changing to paraffin.

[Andy H]

Just started using parafin in greenhouse and runs out so quick! was considering using gas or elec?

Sitting here now at 00:46 it is 2.5C outside and 8C in greenhouse.we seem to have biggest para heater 10M in GH.Must be on max flame.wick running out too soon also!

and burning black a bit? is this due to running out of fuel?

Is elec expensive? probably most reliable though?

was gonna buy new one or bid on Ebay for another para heater that lasts 2 weeks & use big one as back up?

heeeeeeeeeeeeeelp!

[sandersj89]

If it is burning black the wick is probably too high, and therefore the flame. Turn it back a touch and leave for 5 mins and then check again.

The wick may also need trimming. My wicks, on a prasene(sp) big red heater used to last a season at least so I would guess yours is not set right.

Electric is more reliable but do get a decent thermostat to make sure you are not heating when it is not needed.

Jerry

[jo2]

Hi I use parrafin and use my small greenhouse to overwinter things that just need to be above freezing. I'm using it on 4x8 house now which my two tower heater makes lovely and warm but previously I used it on a 6x8 and it just stayed nicely above freezing. Both were well insolated. If I had to use it 24 hours a day it would use 2 gallon in a week(about £6) but in the last few years I've used it I never had had to use it like that-normally its a couple of nights a week through winter and the odd day too when its very cold. Normal running costs are not high as I only have it on when the weather focaste is for below 2C.
Main disadvantages are you have to physically be there to put it on or off which is a blow if you want to go away in winter, and you have to watch the weather forcaste like a hawk as if you miss a night you can lose everything-I tend to err on the side of caution and if I think it looks like the weather will turn nastier then predicated i shove it on anyhow.
Whatever heating you use it will not work without plenty of insolation, I've never had any problems with ventilation with the parrafin heaters as having to go in and fill, turn on/off etc twice a day means the door gets opened and plenty of fresh air gets in.

[campanula]

i have a large cold-frame which does for overwintering but i would love a greenhouse. I would have it really well- heated (gas is an option instead of leccy) so O could grow fabulaous conservatory plants - sod the expense.
cheers suzy
ps, the cold frame is terrific as it is all lined with polystyrene, with twin wall glazing and breeze block construction - I have never had to provide extra heat and have never had a plant loss from the chill.
But I can dream........

[Garden Manager]

Ok so I now have my greenhouse set up, got a heater appropriate to the size of the house (a 'Parasene 4' if anyone knows this range).

On sunday with cold weather forecast I got the thing set up, and worked out how to use it - simple enough considering some of the scare stories about parafin heaters. So i set it going in the 'house, open the louvre for ventilation (the vent has an auto opener so cant open it manualy).

next morning all well and good- inside was a bit smelly but no apparent harm to plants. Thing is the heater didnt really make all that much difference  and only just kept things above zero (outside approx -2.5). I am beginging to wonder if the heater isnt powerful enough (like I said a Parasene 4 in a 6x5 GH - which should be fine).

Its Ok at the moment whilst I am only protecting plants that are only just frost tender (fuschias and pelargoniums), but what happens when i start growing from seed? Seeds need a stable temperature to germimate and grow, at the moment the temperatures are fluctuating too greatly (the 'house also gets plenty warm enough even of a sunny winters day).

basicaly i am not sure how to deal with this problem (being a greenhouse novice). Any advice would be welcome. Thanks

[Andy H]

Know what you mean Richard, I got a new "10" heater,didn`t make that much dif to temp and used loads of parafin.
Got two "ancient" heaters from my mate that he inherited from his dad and they are great. One has a round wick,fuel guage! etc. uses 1 quarter of the fuel for the same heat. Fluctuations are a major problem. I now use to keep frost free.
I think a major plus would be insulation ie:bubblewrap the greenhouse. But I think the only way to keep a constant is good insulation and thermo control heater. I was wondering if worth keeping warm over winter, just frost free for a few plants and use GH to start stuff early rather than trying to grow in the depths of winter, there is also less light in winter too which doesn`t help.

Still, there are experts out there who must be able to help!
My advise is stay away from expensive modern para heaters and find an old ancient rusty thing that is economical! :-\