As the weather starts cooling this time of year, space heaters start getting popular again. You’ll start seeing more ads for them and they’ll start filling up store displays. Space heaters come with some pretty hefty money saving claims. Your actual savings depend a lot on how you use them, however.
Heating with a Space Heater is Less Efficient than You Think
If you live in town and your primary heat source is natural gas piped into your home, a space heater is actually much less efficient than your regular gas furnace. An electric heater costs roughly twice as much to produce the same amount of heat as your gas furnace. Also, contrary to popular belief, electric infrared space heaters are no more efficient than any other electric heater. Although they create the heat slightly differently, your cost per therm is the all the same on anything you plug in to a wall socket. Period.
If you live in a more rural area, however, your furnace likely runs on propane or heating oil. Propane and heating oil are much more expensive than natural gas, and typically are also more expensive than electric heat. In this case, electric space heaters can easily save money.
If you want to get in the nitty gritty of the numbers, Sensible Energy has a great breakdown of the numbers.
Space Heaters Save By Heating a Smaller Area
The primary way that space heaters save you money is by allowing you to be selective in your heating. The theory is that since you spend the majority of the time in a small portion of your house, you use the space heater to just heat that area, allowing you to avoid spending money heating the entire house. This is also known as zone heating.
Using Space Heaters In The Sticks
Our first house was out in the country and was heated by a propane furnace. Because propane has to be delivered by truck to each individual house, it costs much more than natural gas. Although the Sensible Energy link above doesn’t specifically address propane, propane is just slightly more cost effective than heating oil, and a virtual tie with electricity.
Because of the high cost of propane heating, it was very easy for us to save money by zone heating and so we used our space heaters very liberally. The only time we didn’t have a space heater running was when we were out of the house or when we had our wood fireplace going.
Using Space Heaters In Town
Now we live in town. Compared to propane, heating our house with natural gas is dirt cheap (we went from spending $1500 a winter on propane to spending $150 a winter on natural gas). Suddenly, electric space heaters are a lot less attractive. Now the only way we’d be able to save money with a space heater is by using it to heat a very small space, and turning the whole house thermostat way down. We have a natural gas fireplace in our living room that we use to zone heat during the day. The only time we use space heaters is at night. We turn the house thermostat way down and keep a space heater running in our youngest child’s bedroom, since she still doesn’t sleep with blankets. The rest of us cozy up under blankets to keep warm.
The single space heater that we do use is equipped with a thermostat of its own, to ensure that it only runs when it needs to. The space heater is also an infrared heater, which although isn’t more efficient, is safer. We had a close call with a forced air space heater where the fan stopped working and the heater almost started a house fire.
Use Space Heaters With Care
Space heaters can save you money if you are aware of how their efficiency stacks up against your regular furnace and if you zone heat accordingly. Otherwise, they can end up driving your electric bill through the roof while only slightly trimming your gas bill. Also be conscious of the fire risks posed by some space heaters. Don’t leave them on while you aren’t at home, and only use them in rooms equipped with smoke alarms.