Economics of an electrical vs. heating oil radiator
December 19, 2011 2:13 AM Subscribe
Economics of an electrical vs. an heating oil radiator?
I need a small radiator to heat my conservatory. I assume a 2kW electrical heater will be quite expensive to run, but how much cheaper would an oil heater be? B&Q sell a suiitable looking electrical radiator for about £20-£30, while an oil heater is about £100. If you're familiar with UK fuel prices, does it make sense to go for the oil radiator?
I need a small radiator to heat my conservatory. I assume a 2kW electrical heater will be quite expensive to run, but how much cheaper would an oil heater be? B&Q sell a suiitable looking electrical radiator for about £20-£30, while an oil heater is about £100. If you're familiar with UK fuel prices, does it make sense to go for the oil radiator?
Best answer: Hold on. An oil-filled radiator is an electric radiator. It doesn't burn oil. The oil is just a means to circulate and retain heat within the radiator.
The only practical difference is that the fan heater will raise the temperature of part of the room more quickly by blowing directional hot air, so you can point it at the place where you need the heat (i.e. situate it a couple of feet from your toes). The oil-filled radiator acts very much like a water-filled radiator in a conventional central heating system. It heats the whole room via thermal radiation and convection; it'll take longer before you feel 'warm' because it's designed to heat the room fairly evenly. The heat stored in the oil inside the radiator will continue to give out its heat even when power isn't being supplied, helping to keep fluctuations in temperature to a minimum, and continuing to give off some heat after you turn it off. It's also a lot quieter.
In terms of bringing an entire room to a given temperature, there's basically no difference in efficiency. You could instead use an electric cooker, twenty 100W incandescent lightbulbs, or a really powerful hi-fi amplifier to heat the room. You'd get the same efficiency, give or take not much. This is because converting electricity to heat is very, very efficient. Most of our electricity usage is about trying not to turn it into waste heat.
There are oil-burning radiators around. The ones I've seen are big boxes that are sold to workshops and garages where they tend to have access to waste oil that they can burn for heat. Those are only for use in well-ventilated areas. There are also paraffin heaters for greenhouses. Again, lots of ventilation required, and not for household use.
When deciding on an electric heater, you just need to choose the type that works best for your use of the room. An oil-filled radiator will be best for keeping a room constantly warm (or warm for 12 hours a day, say). A fan or halogen heater is better when you need a quick blast of heat to keep you warm for an hour or so at some point in the day.
posted by le morte de bea arthur at 3:14 AM on December 19, 2011 [4 favorites]
The only practical difference is that the fan heater will raise the temperature of part of the room more quickly by blowing directional hot air, so you can point it at the place where you need the heat (i.e. situate it a couple of feet from your toes). The oil-filled radiator acts very much like a water-filled radiator in a conventional central heating system. It heats the whole room via thermal radiation and convection; it'll take longer before you feel 'warm' because it's designed to heat the room fairly evenly. The heat stored in the oil inside the radiator will continue to give out its heat even when power isn't being supplied, helping to keep fluctuations in temperature to a minimum, and continuing to give off some heat after you turn it off. It's also a lot quieter.
In terms of bringing an entire room to a given temperature, there's basically no difference in efficiency. You could instead use an electric cooker, twenty 100W incandescent lightbulbs, or a really powerful hi-fi amplifier to heat the room. You'd get the same efficiency, give or take not much. This is because converting electricity to heat is very, very efficient. Most of our electricity usage is about trying not to turn it into waste heat.
There are oil-burning radiators around. The ones I've seen are big boxes that are sold to workshops and garages where they tend to have access to waste oil that they can burn for heat. Those are only for use in well-ventilated areas. There are also paraffin heaters for greenhouses. Again, lots of ventilation required, and not for household use.
When deciding on an electric heater, you just need to choose the type that works best for your use of the room. An oil-filled radiator will be best for keeping a room constantly warm (or warm for 12 hours a day, say). A fan or halogen heater is better when you need a quick blast of heat to keep you warm for an hour or so at some point in the day.
posted by le morte de bea arthur at 3:14 AM on December 19, 2011 [4 favorites]
... on preview what le morte said. On a personal note we use a sealed oil filled radiator to keep our imfants room cozy and saw no bump in our bill although it runs most of every night.
posted by chasles at 5:25 AM on December 19, 2011
posted by chasles at 5:25 AM on December 19, 2011
Also an oil filled heater will have no exposed parts that get to flame temperature. They are safer around kids, papers, drapes and the like. Safety cages on resistance heaters are a lot better than they used to be, but possibly a consideration.
posted by meinvt at 6:30 AM on December 19, 2011
posted by meinvt at 6:30 AM on December 19, 2011
Are you growing plants in your conservatory?
If you are, I recommend the fan heaters because they serve two purposes - heat and air movement. Plants in areas with more stagnant air are prone to fungal infections and pests.
Also, the gang in my local Cactus and Succulent Society think the more important thing is to get an accurate external thermostat that will measure the temperature where you want the heat to be rather than where the heater is (and most heaters have inaccurate thermostats).
If you do get a radiator put it by the window so the convection stops cold drafts.
posted by srboisvert at 7:27 AM on December 19, 2011
If you are, I recommend the fan heaters because they serve two purposes - heat and air movement. Plants in areas with more stagnant air are prone to fungal infections and pests.
Also, the gang in my local Cactus and Succulent Society think the more important thing is to get an accurate external thermostat that will measure the temperature where you want the heat to be rather than where the heater is (and most heaters have inaccurate thermostats).
If you do get a radiator put it by the window so the convection stops cold drafts.
posted by srboisvert at 7:27 AM on December 19, 2011
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It's hard for me to say exactly what your experience would be though, without knowing the electric or fuel prices you'd be paying. An educated guess would be the oil heater would be even more expensive for you.
posted by neversummer at 2:23 AM on December 19, 2011