How expensive are electric heaters to run?
- MonkeyDavid
- Posts: 417
- Joined: Fri May 15, 2009 7:12 pm
- Location: Telford, Shropshire
How expensive are electric heaters to run?
I've been wondering for some time about the running cost of an electric heater in a greenhouse. I currently have a paraffin heater which cost about £7ish a week to run & is usually sufficient except in extreme cold when the temps drop too low for my liking & it also becomes almost impossible to buy any as everywhere sells out. i Know all about the pro's & con's regarding how good they are & water vapour etc but what about ££££? I've worked out if i had a 1kw heater running for 24 hours a day in 1 week it'd cost about £19. Obviously it wouldn't be on 24/7 but what would it cost in the real world? ( i only need frost protection) eg, how long does it switch on compared to off in this cold spell?
- Dave Brown
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Re: How expensive are electric heaters to run?
David, that is an impossible question to answer
Requirements are
What size
What insulation
What Outside temperature
My polytunnel is.... on frost setting controlled to +1.4C
Size: 3.5m x 2.1m x 2.1m
Insulation: Insulated by big bubble, bubble wrap (whole surface) and 2.5cm thick polystyrene sheet on bottom 90cm of sides.
14W extractor fan sucking 103 cu/m per hour from ridge to floor
Heat blown across floor by 30W 16" oscillating fan
Both of these run 24 x 7 while the greenhouse is closed down.
Outside Temperature -1.5C
1Kw heater was coming on about 30sec in 3 mins...... 1/6 th of the time. which would equate to 4kw/h per day or 28Kw/h per week.
Fans = 44w x 24 x 7 = 7.3kw/h per week
At an ave temp of -1.5C heating system is 35.3Kw/h
However, I have twin rate electricity and 7 hours of the night is under 50% of day rate.
so for me at an average temp of -1.5C works out at £4.63 per week.
HOWEVER,
Your greenhouse exposure/ insulation etc will be different
Requirements are
What size
What insulation
What Outside temperature
My polytunnel is.... on frost setting controlled to +1.4C
Size: 3.5m x 2.1m x 2.1m
Insulation: Insulated by big bubble, bubble wrap (whole surface) and 2.5cm thick polystyrene sheet on bottom 90cm of sides.
14W extractor fan sucking 103 cu/m per hour from ridge to floor
Heat blown across floor by 30W 16" oscillating fan
Both of these run 24 x 7 while the greenhouse is closed down.
Outside Temperature -1.5C
1Kw heater was coming on about 30sec in 3 mins...... 1/6 th of the time. which would equate to 4kw/h per day or 28Kw/h per week.
Fans = 44w x 24 x 7 = 7.3kw/h per week
At an ave temp of -1.5C heating system is 35.3Kw/h
However, I have twin rate electricity and 7 hours of the night is under 50% of day rate.
so for me at an average temp of -1.5C works out at £4.63 per week.
HOWEVER,
Your greenhouse exposure/ insulation etc will be different
Best regards
Dave
_________________________________________________
Roll on summer.....
http://www.hardytropicals.co.uk
Dave
_________________________________________________
Roll on summer.....
http://www.hardytropicals.co.uk
- MonkeyDavid
- Posts: 417
- Joined: Fri May 15, 2009 7:12 pm
- Location: Telford, Shropshire
Re: How expensive are electric heaters to run?
Granted Dave, everybody's cicumstances will be different & i know there are a lot of variables, but i thought a few people giving their experience would give a ball park figure, your figures give me something to work with, Although someone who has recently switched to electric would be ideal. Basically i need to prove to the other half that it isn't going to cost too much more than paraffin too much of a pain in so many ways to use but she only thinks of cost
Re: How expensive are electric heaters to run?
I have a Dimplex Coldwatcher 500w and an old tube like heater in my homemede greenhouse.One side is brick and insulated with polystyrene sheets,the rest is made up of double glazed doors and a polycarbonate roof,there are a few gaps here and there.Last year while away on holiday we left the heaters on for 2 weeks and had some minus 7s in that time and i worked out it cost no more than £15 for the fortnight.My other half say's its a hell of a lot cheaper than having to replace all the plants,and even reminds me to turn the heaters on if frost is forecast.!Hope this helps
Re: How expensive are electric heaters to run?
I have an 8 x 6 greenhouse lined with bubblewrap.
The heater is a 2kw fan heater set to the 1kw setting.
I installed it just over 2 weeks ago and its running 24/7 with the thermostat set to maintain 3°c so its seen the worst of the weather here.
I just checked the consumption over that period and its 23.58KwH
If your wondering how i know this the heater was plugged into a power consumption monitor to record the power used over that duration.
23.58KWH works out at £2.64 or about £1.32 a week.
I am staggered that it is so low. Paraffin was costiing me over double that figure so i am well pleased that i moved to the fan heater.
The heater is a 2kw fan heater set to the 1kw setting.
I installed it just over 2 weeks ago and its running 24/7 with the thermostat set to maintain 3°c so its seen the worst of the weather here.
I just checked the consumption over that period and its 23.58KwH
If your wondering how i know this the heater was plugged into a power consumption monitor to record the power used over that duration.
23.58KWH works out at £2.64 or about £1.32 a week.
I am staggered that it is so low. Paraffin was costiing me over double that figure so i am well pleased that i moved to the fan heater.
Re: How expensive are electric heaters to run?
I heat a large 18 foot by 8.5 foot, large bubble wrap, to a minimum of 5°C. There is not much difference between my summer and winter electricity bills. In the summer, we run an immersion heater to heat our water for the house, probably on 3 1/2 hours a day, 3 kW, not in winter (back boiler). So about 10.5 kwh per day, whatever that costs you (very similar to musa_monkey's 11.79 kwh). This is in an average winter though, current winter is probably double that for me!
Re: How expensive are electric heaters to run?
Check out Two Wests & Elliott catalogue,they give a rough rule of thumb to what how much kilowatts you'll need for a given size.Double glazing it will reduce your heating bill by around 40%,but use the double-skinned large bubble plastic.Also,for every 5c you raise the temperature,you'll double yor heating bills.Poly tunnels are harder to keep warm than a glasshouse.
metalhammer.
metalhammer.