Q&A: Will using space heaters lower my heating bills?

I heat my home with natural gas but am considering using electric space heaters to try to cut costs this winter. Can portable heaters help me save, or are the claims I've seen just a lot of hype?

If your heater is equipped with a good thermostat and you do not heat the room to a warmer-than-normal temperature, you can save money by using an electric space heater in a room you’re in and keeping the rest of the house chillier. How much you’ll save depends on the room size relative to the rest of the house, how well separated the room is from others in your home, and how you use your space heater.

Like you, most Americans heat their homes with natural gas. Our experts say that if you were to use an electric space heater to warm one room to your normal room temperature and lower the temperature in the rest of the house, the amount you'd save would depend on how much heat that area requires relative to the rest of the house. If the heat required is less than half the total for your house,then you should be able to reduce your overall energy costs. Remember, on average, electricity in the U.S. is about twice as expensive as natural gas for the same amount of heating. So, for the same cost, you can heat only half the area.

Other ways to lower your heating costs, according to our in-house experts, include:
• Turning down your thermostat. Even lowering it 1°F reduces heating costs by about 3 percent.
• Improving the heat distribution of your central furnace instead of using pricier electricity to warm your home. If some rooms are too warm and others are too cold, the heating system is unbalanced and needs adjustment.
• Using a setback thermostat or turning off the space heater. If you go to bed at 11:00 p.m., set the temperature back at 10:00 p.m. or even earlier, or turn off the space heater well before you leave a room. Your house or the room won’t become uncomfortably cool immediately.
• Wearing on a sweater—or two. Mom was right: Extra clothing will keep you comfortable at a lower room temperature.

Finally, be safe when using a space heater. Electric space heaters cause an average of 3,000 fires each year in the U.S., often because of improper use, according to the National Fire Protection Association. Read the NFPA’s safety advice and our coverage of the risks associated with propane and kerosene heaters.

Essential information: “Save hundreds on energy costs” features expert advice on cutting your utility bills. See our recent reports on compact fluorescent lightbulbs, thermostats, and windows, all of which can help you lower energy consumption at and enhance the comfort of your home.

Comments

[Jonathan Beers]

I'd respectfully suggest consulting with another set of experts to get a better answer to this question. I'd suggest Oak Ridge Nat'l Lab in Tennessee, Advanced Energy Corp. in North Carolina or Home Energy Magazine (a side project of Lawrence Berekely Nat'l Lab). Your estimated savings from the "warm room" approach are overestimated in my opinion. Here's an email exchange I had on this topic w/ a researcher at a non-profit energy research and demo lab. (I'd want to get his permission before publishing his name and affiliation, can do so if you like).

Jonathan wrote to a researcher:
"We're getting a lot of questions about the economics of keeping one area warm w/ a secondary heating source and letting the rest of the house
get colder. We ask them about the efficiency of their primary heating source and the alternative they're considering.

For the following primary/secondary heating combos, I tell them it's probably not going to work: condensing furnace vs. a) open hearth product [even w/ glass doors] b) 78% or higher efficiency (AFUE) gas furnace vs. electric resistance heating.

Things get a little muddier when the secondary sources are wood stoves with a below market-rate source of wood, or sealed combustion gas fireplaces, or pellet stoves. (Or if they have lower efficiency furnaces.)

Reply from colleague:
"It comes down to (a) relative efficiencies and cost, (b) how much of the house they let get cool, and (c) how cool they let it get. Given that interior partitions are usually not insulated, my guess on (c) would be probably not cooler than
about 55F, which might then translate into 25% less primary heating for that part of the house. If that was say half the house, then you're looking
at about 12% savings."

[Daniel Mackolin]

How to use compressed air to drain system water in winterizing a
a summer home. Heat to be set at 50.
Thanks

[Wally]

This report was frustrating in 3 major omissions.

1. It didn't clearly define what a convection or radiant heater was. It didn't link the ratings to pictures. Often, it's hard to find the exact model of anything rated by CR in stores (and sometimes I don't take the article and ratings list with model numbers)but I can compare products based on understanding the ratings and the features. Not possible without a clue of what the rated models are.

2. It didn't discuss relative efficiency of the space heaters. How do I compare how much it costs to provide a heat boost? Sure, you supply the wattage WHEN RUNNING, but how about how much energy each takes to maintain that temperature?

Sometimes, I just use a space heater to "take the chill off". For instance, our basement playroom is generally cooler than the rest of the house. Some days I have no intention of running the furnace at all, but want the kids to be comfortable until the house warms later in the morning. Similarly, I take the chill off the bathroom before showing, in Spring and Fall. Also, I keep the vents in the project room nearly closed. When I use the room, I open the vents and run the space heater until the room heats up. Yes, I could plan ahead and open the vents earlier, but do I always have the time or foresight? No. I keep a space heater in the guest room in case my guests need a bit more heat than my normally cool house. Obviously, this is about comparing costs between heaters for convenience and short term use - not about comparing to my furnace.

3. Different situations call for different features. Usually, CR addresses this. A space heater with fan worked great for me in the leaky garage workshop, but dried the air enough to uncomfortably dry my eyes when watching TV. I prefer an oil-filled electric radiator in the playroom because it continues to heat even when it is not using power - a gentler heat. Your ratings need to cover more about which heater is best in several situations (such as a room that is drafty, seldom used (and perhaps has heat distribution problems that aren't worth investing in modifying the whole house system), or needs heat when the furnace isn't running.

Hope to see more information in future articles. Thanks.

[Mrs D.]

I purchased the heat source for my family room in lower my thermostat to 64 and normally have keep it on 68 and it will constantly clickon in that room i have ssen a different in my oil fill up but i do recommend to run a humdifier if you run on high for a few hours i see i saving in oil of course i will see a different in my electric bill but not bad may 20 dollars higher but oil is very expensive.. and thats where i see a savings

[Mary Larkins]

I know from personal exprence those things do not work the thing thats supposed to put out the heat is a scam it ran my electric bill up $70.oo some dollars, Ican tell you now my credit card got my money back for me! I hate to see people lose their money on junk!! THANKS FOR HEARING ME OUT, I SWEAR IT'S THE TRUTH Mary Larkins