It’s cooling off, time to turn on the furnace. Problem is, natural gas prices are expected to rise by 60%! I am considering using a portable space heater to augment my heating system instead of cranking up the heat in the entire house. Any preferances on electric space heaters? I was thinking about the oil filled radiator type. This seems safe but are they efficient? Any suggestions from the tundra would be aprreciated.
All electric space heaters are 100% efficient. Normally, any wasted energy is dissipated as heat- but in this case, heat is what you want, so it doesn’t count as inefficiency :).
I’m a fan of the oil-filled radiator type. In my opinion they’re the safest. The peak surface temperature of the heater is pretty low, so it’s hard to get burned by one accidently. Also, there’s no way for a child to poke something inside and touch any hot coils. Finally, you can rest your feet on top and warm them up
Disadvantages include: more difficult to carry around (especially up stairs), takes a long time to heat up from cold (10-15 minutes to really start radiating heat), expensive.
Most electric space heaters have a high setting of around 1500 Watts, which is 1.5 kHw per hour, which 8.25 cents per hour in my area (5.5 cents per kWh), or about $12/month for 5 hours per day of use (assuming it’s on the entire 5 hours).
All electric heaters have 100% efficiency. That is, all the electricity consumed by the heater turns into heat. Where else can the energy go?
Of course, some heaters (like the radiator type) heat the air, while others (radiation type) heat your body and walls directly. Some rely on natural convection to distribute heat through the room, while others have fans to force circulation.
My personal opinion is that the kind with built-in fans are most practical. Radiation type (the kind with a tube that glows red) is not very comfortable, because the side of your body facing the fan gets too hot. The oil-filled radiator type takes a while to warm up, and even longer till it warms up the whole room through natural convection. Once the room is warmed up, though, the radiator type is more pleasent than the fan type. (I wish I knew the proper terms for each type…)
My parents have had the most success with kerosene space heaters with built-in fans and built-in tanks. They are very powerful and cheap to operate, far cheaper than electricity. Only problem is that you need to ventilate the room every couple of hours, so you can’t use it while you sleep. And, of course, you have to fill the tank every week or so.
Also, I think natural gas is still cheaper than electricity for the same amount of heat. Have you considered wearing a sweater in the house, and getting a warmer comforter for your bed? You don’t need heat during the night - if it’s too cold to get up in the morning, just set the timer on your electric heater so it starts an hour before you get up.
As far as efficiency of any electric space heater, it makes absolutely NO difference. Thay are all going to put ot exectly the same amount of heat per Kwh consumed. I have a small one with a fan under my desk. Just be careful about safety. The larger, oil filled are generally considered safer as they do not get so hot, but they are only good for generally heating the entire space, whereas a samll fan or infrared type can be more precisely directed. If you have one (say) under your desk, heating your legs, then you do not need to heat the entire room so much.
You do realize that natural gas is cheaper and the savings come only from heating a much smaller space.
In my case: gas = 90 cents/therm. Assume furnace efficiency 85% and net cost = $1.05 /therm = 3.6 cents/Kwh
Electricity: 5.267 cent/Kwh for the first 400 Kwh, 9.046 after that. Assumming you use the first 400 just for you basic household use, then the price you are paying for electric heat is the higher price which is 2.5 times the price of gas heating. Gas price would have to go up by a factor of 2.5 before it equaled that of electricity.
Your number will be different but, as an example this is valid. Do the math before buying an expensive space heater. You might find it is not such a good idea after all.
Thanx to all for the replies. In lieu of maintaining a high temp. in the entire house, a large house, my intent was to use the heater for one room, and lower the thermo for the entire house. Bedrooms are upstairs and they naturally stay warmer. Think I will try the oil-filled, but you are correct, they are expensive and their recovery rate sucks.
And a special thanx to sailor for the numbers.