My neighbor was telling me that his oil filled radiator type space heater is more efficient than the kind with a fan and heating coils. I told him that there is no difference, that all the electricity consumed by the heater is converted to heat in the room. Even the sound made by the fan vibrates the air which heats it up a little. So if both were operated in a perfectly insulated room and consumed the same amount of electricity the rooms would heat up the same amount. Now I'm wondering about real world situations. Some frequencies of light pass through walls, some through windows, some both, and some neither. So I suppose the best heater is one that glows in a frequency range that is completely absorbed by objects (including people) in the room and reflected by the walls and windows. Are my asumptions correct? I hope so. Otherwise I'll need to call my neighbor so he can serve me a little crow. Eric
A basic question about electric heaters
Nov 21, 2011
11 Replies
There are two kinds of electric space heaters, convection and radiant. Convection heaters (attempt to) heat the entire room, radiant heaters heat objects, including you. The oil filled radiator is a convection heater, as are the heating coil plus fan heaters.
Comparing convection heaters to convection heaters, there is no difference in efficiency, 100% of the electrical energy does turn into heat. The Department of Energy prefers the oil filled units because their thermal mass makes them a more constant heat source. Their heating elements cycle less, for what it's worth.
But, radiant heaters should have more apparent efficiency in that they require less energy to heat just you instead of the entire room plus you in it.
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Correct, if you ignore one minor detail. Since a radiant heater warms you, rather than the air, you will always feel colder on the side away from the heater.
PlainBill
True.
The only thing, radiant might be considered more efficient because inducing drafts might make the air feel colder.
Greg
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I don't know what the efficiency of radiant conversion is, but radiant heaters give out plenty of heated air also. Some also have fans.
Greg
That said, I have not yet seen an oil filled heater more than a few years old that did not leak to some degree. Not sure what might happen if the oil level drops to the point that the heater element starts boiling it.
Neil S.
I've had mine for 15 years, and I bought it used. Soon, it'll be time to drag it out for another winter.
You can't have a sense of humor, if you have no sense.
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Not necessarily. Glass is opaque in the infrared range. However, they WILL absorb the energy and if single pane will release half the heat generated outdoors.
PlainBill
Are those things full of used chinese motor oil or something else you don't want to touch or have catch on fire?
Where do you think they're putting all that pcb tainted oil?
Ha, I figured they used all that stuff up in foods and to polish rice by now.
Duzzat mean I should avoid brown rice?
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