Heating a greenhouse

[pigletwillie]

oops,

whilst its all very well starting your plants off early, when it came to pricking my peppers out into 3 inch pots I suddenly found that I was about 20 ft of sunny windowsill short. There are also aubergines and tomatoes to come so problems were literally growing before my eyes

A quick dash to Tescos produced a brand name 2Kw heater for less than £13 and a trip to the allotment shed brought some fleece for extra protection on colder nights. I have the heater at present keeping a temperature of 14 degrees C which may drop a little if its frosty to perhaps 10 degrees C hence the back up of fleece.

Do I need to keep the temperature this high, will 10 degrees C do or is that a wee bit chilly for chilli, pun definitley intended.

[nog]

How much is that going to cost 2kw over 24hours x7. Ouch.

[pigletwillie]

its not too bad really as it isnt on all of the time and to offset it I have turned off my 1500w pond pump for the winter. I will be blowing its socks off though if the weather goes below zero.

A gas heater will be in soon

[nog]

We went through this some time ago I am using Parrifin but it is now £5 for 4lt. I was given a big supply a few years ago but this is now at its end. People were saying Propane/calor was the cheap way to go but I have now put power into one of my Greenhouses so may go electric....but am worried about the bills.

[Guest]

do as i do and wait till it gets warmer,im such a stinge bag

[Chantal]

I heat my greenhouse with a parasene frost stat type of fan heater and thought my bills would be astronomical, especially last year when a child went (without my knowledge) into my greenhouse and left the door open. It was open for a WEEK in FEBRUARY with the fan heater on 24/7 but my fuel bills were not much higher than usual; I thought I'd need a second mortgage. Yeah it costs a little bit, but it's worth it...

[pigletwillie]

Thanks for that Chantal, Mrs Piglet wont have to hawk around the train station this week then for 10 bob to put in the meter.

Is 10 degrees enough though

[Chantal]

I don't have a clue! At the moment I have seedlings in the propagators so they're fine and I have the heater set to come on if it hits zero in there. When stuff comes out of the propagators I turn the heater up from frost to about number 5. I don't check the thermometer too much though, if it feels chilly in there first thing I set the heat higher and if it's too warm I turn it down a bit. It's all on how the air feels and how things are growing and not at all scientific, sorry.

What's Mrs Piglet hawking at the Railway Station? More of your homemade pickles?

[Tigger]

I've got what we call an 'inner temple' in one of my tunnels (the one with electricity, surprisingly) which is a 'room' made from tannalised timber covered in two layers of bubble wrap (from the farmers suppliers shop), so it's well insulated. I keep all my precious gems in there for overwintering and as plants come out of the propagator, they also go in there. I've got an electric frost watch heater in there, the same make as the one I have for the dog's room in the barn. They both run all winter and there's no significant difference in the electric bills between summer and winter.

[secret guest]

we have a fan heater set on its frost seting, i.e. around 4deg. C. It only comes on at night, on economy 7 'lectric, so it is pretty cheap to run. We also have heated beds, but they don't take much power. It has been so much better than worrying if the paraffin heater has run out or the wick is too long or whatever.

[bigpepperplant]

i've got a couple of propane heaters with thermostats in the top end of the polytunnel, which is separated from the rest of the tunnel by plastic and insulated with bubblewrap.

The thing is, I'm too scared to leave them on all night because I live 40 minutes away and am terrified that something will go wrong with them and burn the place down... (not that theres any evidence that they're unreliable. Has anybody ever had trouble with propane heaters or are they totally safe and I should just turn them on to 5 degree c or so and relax...

[Allan]

I have propane heaters at the farm but they are not in use at present simply because they have been going out for no apparent reason. likewise the propane heater here. I am at present running this glasshouse electrically which is much better for the benches as I can do bottom heating, very economical.
The latest is a 6x4 ft propogator running at 13 deg C. just on bottom heat.
Allan

[pigletwillie]

I suppose if it all went pear shape, it would be all over so quickly it wouldnt matter if your polytunnel was in your garden or 40 minutes away.

If you ensure that there is nothing flamable too near the heater all would be ok, perhaps

[bigpepperplant]

thanks for that, yes wish I just had electricity, it would be far easier, but unfortunately the site's not on the grid and my extremely noisy generator ('Silent'? as if) will keep the neighbours awake all night so don't dare use that either
All this for a few vegetables...!

[darren c]

10 degrees is enough at night time but try not to let it drop below that , enough heat to keep the frost of is the critical thing.There are tricks to help you as i have done in my greenhouse which is 8x6 and heated with a single chimney Parasene parrafin heater which takes a gallon every ten days or so which at £2.70 a fill is not bad. Insulate the inside of the greenhouse with bubble wrap and drop the ceiling height with said bubble wrap to trap the warm air layer closer to your tender seedlings.Raise the height of your staging ,there can be as much as 10 degrees difference in temperature from ground floor to 6 foot up. I run two heaters the other one being an Alladin 203 which was given to me by one of the old boys on my site .This heater is way too hot and thirsty to run all the time so it is only used when severe weather is forecast.I have even looked into a system of solar power or wind generation battery storage and thermostat systems used by pleasure boaters and caravanners but quickly dumped it for cost reasons.