Space Heater vs Central Heating: When the Little Box Actually Saves Money
Updated August 2026
In plain numbers: A space heater saves money in one situation: warming one small, occupied room while you genuinely turn the heat down everywhere else. A 1,500-watt heater at average electricity costs about 26¢ an hour. That's cheap next to heating a whole house and expensive next to a heat pump, which would warm the same room for roughly a third of the price. Running two or three plug-ins, or running one without touching the thermostat, is one of the most common ways people make their winter bill worse.
Where it wins
Electric resistance is the priciest heat per BTU in most states. What it has going for it is aim. One person working in a 120-square-foot office, whole-house thermostat dropped 8 to 10°F, heater on only while the chair is occupied: that trade usually comes out ahead, because warming 120 square feet is cheaper than warming 2,000. Notice where the saving lives, though. It's in the setback. The heater is what makes the setback bearable.
Here's what it looks like on paper. Eight hours a day at 26¢ is about $2.10, or roughly $62 a month. If dropping the main thermostat cuts your gas bill from $180 to $120 over the same month, you're $2 ahead and warm where you sit. If the thermostat stays at 68°F, you're simply $62 poorer.
Also worth knowing before you shop: every 1,500W heater puts out the same 5,118 BTU an hour. Ceramic, infrared, 'eco', $25 or $400, the heat per hour is identical. Pay extra for a real thermostat, a timer, tip-over protection and a quiet fan. Don't pay extra for warmth, because there isn't any extra to buy.
Where it quietly becomes the most expensive heat in the house
At resistance economics, a coefficient of performance of exactly 1, a space heater pays about three times what a heat pump pays per unit of heat and often 1.5 to 2 times what a gas furnace pays. Two heaters humming through the evening while the central system also runs is how a normal January bill turns into a very abnormal one.
The usual way in is 'supplementing'. One room feels cold, so a heater goes in and the thermostat stays put. That adds cost and fixes nothing. A room that's always cold usually has a duct, insulation or balancing problem, and a $10 register adjustment or a Saturday with a caulk gun often does more than a whole winter of 26¢-an-hour heat. If you're weighing a longer-term one-room setup, our guide to heating just one room compares the options that hold up over several winters.
The safety rules that don't bend
Space heaters show up in a large share of home heating fires, and most of those follow the same few mistakes. Plug straight into the wall, never into a power strip or extension cord; they aren't built for a 12.5-amp load for hours and they can melt. Keep three feet of clear space around the unit. Set it on a hard, level floor. Buy only models with tip-over and overheat shutoff, and don't run one unattended or while you sleep.
If a bedroom truly needs heat all night, an oil-filled radiator on its low setting is the safer choice than a unit with a glowing element. It costs the same per BTU, since physics doesn't give discounts, but it runs cooler to the touch and is far less likely to start something at 3 a.m.
FAQ
How much does a space heater cost per hour?+
A 1,500W heater at the national-average electricity rate costs about 26¢ an hour, which works out to roughly $60 a month at 8 hours a day. Every 1,500W unit produces the same heat regardless of price.
Is it cheaper to use a space heater or central heat?+
For one room while the rest of the house is turned down, the space heater usually wins. For several rooms, or with the thermostat left where it was, central heating is cheaper per unit of heat, and a heat pump is cheaper still.
Do 'efficient' space heaters exist?+
Not in the way the ads suggest. All resistance heaters turn 100% of their electricity into heat, so they're identical per watt. Ceramic, infrared and eco models differ in how the warmth feels and in their controls, not in heat per dollar.