electric space heater for 1 room or gas furnace for the whole house?

I have a 1500 square foot 2 story house. I generally keep the heat low, as the place is usually empty, and cold doesn’t bother me or my GF. Tonight was an exception, she did get cold, but she offered to use an electric space heater to keep herself warm in the living room while I worked in the den.

I told her that I was pretty sure it cost less to turn up the (gas forced air) furnace and heat up the house than to use the (cheap-o, not particularly efficient) space heater. But I’m not sure, so I thought I’d ask here. Obviously there’s a lot of factors at play here - how much space she would be heating, how efficient my furnace is, how much gas costs vs electric etc… but is there any general rule of thumb? How much less efficient is electric heat over gas?

In the meantime, I’m going to go turn up the heat - now I’m getting cold too.

The space heater can be inefficient, but using it to heat a room to X degrees should almost always be cheaper than heating N rooms to X degrees. I’d use a space heater.

I’ve also found that space heaters that blow hot air are more effective than “radiant” heaters (that look like a dish).

Personally I use a halogen lamp! I need it on anyway, and it gives off a lot of heat.

I suspect that logic doesn’t apply to my house - the living room is the biggest room in the house, and it’s at the base of the stairs. Since most of the heat’s going to go upstairs anyway, she’s already heating nearly half the house with the space heater. Unless she’s just going to point it at herself.

anyone know off hand how much electricity per house one of those space heaters uses? Compared to, say, how much a typical gas furnace uses per hour?

Stuff a towel under the door and use the space heater.

Do what?

Unless your place is built with an open loft-style second floor, yoo ought to be able to close off the stairwell very cheaply & pretty effectively. I did this and was amazed at the results. You don’t need to waste heat flowing upstairs if you don’t want.

I just used an extendable spring-loaded shower curtain rod to span the “doorway” where the stairs entered the wall. Then I hung an inexpensive premade fabric window curtain from it. I put the rod as high up as I could and the curtain hung to within about 6" of the floor. Cost about $40 total at K-Mart / Target. To use the stairs, just brush the curtain aside as you pass; it closes behind you automatically.

The effect was immediate & dramatic; much greater than I expected. The temp difference across that flimsy peice of velour is 10 degrees. And it doesn’t look bad either.

I’d say try that and a space heater & you’ll be money ahead over heating the whole house. Note that if you do cork off the stairwell you’ll probably have to readjust the upstairs air vents to add more heat up there; the current adjustments assume a lot of heat flow up the stairwell that just won’t be there. Then again, if your upstairs is overheated ccompared to downstairs now, blocking the stairwell would solve that.

I have a little space heater that uses either 1300 or 1500 watts. So that’s 1.3 or 1.5 kWh charged for each hour of use. My current electrical charge is about $0.11031 per kWh, so running the space heater on high for an hour should cost me about 17 cents. I have a gas furnace and I’m not sure how to easily break down usage, but one dekatherm of use (all I’ve been using the gas for in the summer is the water heater, so I go through about 1 dekatherm every two months) last month cost me $7.2098. Let’s go with one month last winter when I used 5 dekatherms at $9.8316, so the gas cost was $49.16. Assuming that it was five whole units and not fractional and that the hot water heater alone counted for one unit, call it 4 dth for $39.33. This was a February, so call it approximately $1.40 a day or $0.058 an hour. Of course, I had shut the registers in several areas, turned the heat off entirely during the day and generally turned it off when I went to bed and even when I was up and about I was more likely to put on more clothes instead of using the furnace. Thus it was nowhere near this linear in usage but more of a ramp up from like 55, maybe stabilize at 70, ramp down to 55, and so on, so a lot of usage was getting to and from 70, not keeping a constant temperature.

Still, though, I say that if you are comfortable, more money can be saved by running the space heater on as low a setting as possible. It’ll depend on the wattage of the space heater.

Also consider safety factor. House heaters rarely set the place ablaze-the same can’t be said for space heaters. Accidentally knocked over, pet/child pushes combustibles too close, cord becomes worn and begins to arc-the scenarios are numerous, as are the fire reports. Use only with great diligence.

This is exactly the kind of answer I was looking for. Thanks!