The Cost of Electric Heating

[Susiebelle]

I would like electric heating in my greenhouse but am really unsure as to the ongoing running costs. The capital outlay in installation is manageable and I do need lighting but it's the running costs to heat that worry me :-\ can I ask for any thoughts on this subject as  I really am struggling!

[Susiebelle]

[silly billy]

I switched to electric heating for my greenhouse after using a parafin heater for a couple of years. One advantage is you can use a heater with a thermostat so it only comes on when actually needed which can help to keep it frost free.The parafin heaters have to be on all night. If costs are a worry then I would advise you to insulate the greenhouse with the bubble wrap type insulation which will help to reduce the costs.

[tim]

Think - what for?

How warm does it have to be?

What size 'house?

[Tee Gee]

Look at this way if you use a soil cable they only use a similar amount to an electric light bulb I think mine is 80watt.

Then by adding a thermostat you can even control this, failing that use a time switch.

I have a 2kw fan heater that has only been on about three or four times over the last two years.

This my set up; http://tinyurl.com/3ca7gw

[Susiebelle]

Thanks for all the comments it all helps concentrate the mind, and whow! Tee Gee that set up is something to aspire to, I'm working on it watch this space ;) ;)

[katynewbie]

 :-\

Gardeners Question Time on R4 this week had someone saying she was going to make a compost heap in her greenhouse. It would be along the middle and would gently warm up the surrounding space!

Worth a go?

???

[tim]

My only heat is for seedlings - from a bench sized thermostatic hot mat, with capillary mat6ing on top. That gives warmth up to 10" above mat level?

[Susiebelle]

Tee Gee my OH is intrigued by the "outside" insulation as referred to on the setup website - I have bought bubble wrap for insulation purpose, but this surely would not stand up-to the winds etc - what do you use & how do you secure?
I like the capillary matting idea, I am useless in the DIY department  so this may be attainable for me - thank you Tim.

[Tee Gee]

what do you use & how do you secure?

1) My greenhouse is made of timber so it is easy to fix things with screws & drawing pins.

2) I use cellophane not bubble wrap

3) I drape the cellophane over the roof and wall then hold it in place with laths screwed to the greenhouse frame.

4) Where I have autovents I cut the cellophane around the opener and hold it in place with drawing pins this way it can open & close at will.

5) My greenhouse is in the most sheltered part of the garden, but thats not to say it isn't affected the win but my fixings cope.

6) What you have to be ready with is tape & drawing pins if a tear appears as this can soon develop into a situation where you lose the lot.

Touch wood I haven't had this problem to date :)

I hope that clarifies things for you.

[Susiebelle]

It certainly does Tee Gee,sadly my greenhouse (pride & joy) is not wooden ???, but your method has given me food for thought and I will not give up on the idea just yet.  Many thanks for galvanising me into action.

[valmarg]

We used to bubblewrap the inside, and keep the greenhouse heated with an old Parwin thermostatically controlled fan heater, basically to keep the greenhouse frost free.

Now, like tim and Tee Gee we only use heat for seedlings/cuttings.  We have a thermostatic hot mat.  We also have a very old soil warming cable, which OH has made a wooden frame for.  You basically zig zag the cable across the base and cover with sand.  It acts as an enormous propagator.  OH has also made hoops to go over it so that we can drape fleece over it if it's going to be really cold.  We got the idea for that from a Two Wests catalogue.

In Spring when space is starting to become scarce, we have some four tier mini-greenhouse stands we bought from Focus, and we put them in the greenhouse, together with their covers as double insulation.

We only use the Parwin heater in Spring to keep the frost at bay, but if you are going to buy a fan heater I would recommend the Parwin.  Ours is years old and has given very good service, also in Summer when it's very hot it can be used on cool to circulate the air.

valmarg

[Susiebelle]

Thanks Valmarg, I will be researching the Parwin as it certainly seems to get everyone seal of approval!

[northener]

If your only running a mat you could run it off the sun. You use a solar panel (£20 maplins) an inverter(changes 12v dc to 240v ac  £40 maplins ) and a car battery. I'm going to be running a propogator this way. My only worry is someone nicking the gear, solar panel will attract magpies round here.

[Susiebelle]

Thanks Northener, this sounds interesting 8) 8)

[laurieuk]

My parwin is now about 30 years old, it is the only firm that I know that instead of selling me a new motor, which I thought I needed, sent me two small washers free of charge to take up the bit of wear.I have it running most of the time with the thermostat set just above 34 0 c . with the fan going it stops cold corners forming and the temperature does not fluctuate so much.

Thanks Valmarg, I will be researching the Parwin as it certainly seems to get everyone seal of approval!

[Susiebelle]

High praise indeed! thank you Laurieuk