I'm home alone most days, and I try to keep the heat in my drafty house down to about 62 degrees during the days. I don't want to let it get any colder because it would be hard to warm up when the kids got home from school, and because I would be really, really cold. I have a small electric space heater that I keep under my desk because that is the place where I'm usually the coldest. So I got to wondering – is that really efficient? How much electricity is my space heater using? Is this the best choice for my situation?
Here's what I found out:
photo by: Jo Jakeman
First, I hadn't considered how many types of space heaters were available. Spaces can be heated with natural gas, propane, kerosene, electric or
wood heaters. Electric heaters are the most popular because they are
easily obtained, portable and easy to operate. However, they are the
most expensive form of space heating so consider whether a more
permanent solution is better for your specific situation. I'm going to focus on electric space heaters because that's what I have, and that is the easiest choice for most people.
How do you choose an electric space heater?
- What kind of heating do you desire? Are you looking to heat a small space (like under my desk) or a whole room? Do you want to use it constantly or intermittantly?
- Do you want a model with a thermostat, or will you manually turn it off and on as necessary?
- Do you have small children or curious pets?
Safety is an important issue when purchasing a space heater. The US Consumer Product Safety Commission estimates that more than 25,000 residential fires are caused each year by space heaters, resulting in 300 deaths. An additional 6,000 emergency room visits result from space heater burn injuries every year. Here are some space heater safety consideration:
- Make sure that is has the UL (Underwriter's Laboratory) certification label.
- Look for safety features such as overheating shut-off and a tip-over safety switch that will turn off the unit if it is tipped over.
- Plug directly into an electric outlet, or use a heavy duty extension cord. Do not use a standard extension cord.
- Do not run the cord under carpets.
- Keep the area free of all objects.
- Place on a hard, flat surface, preferably the floor.
There are several types of space heaters, but specifically there are radiant heaters and convection heaters, which may or may not include a fan to assist with the convection.
- Radiant heaters work by emitting infrared radiation that directly warms up anything in it's "view." Radiant heaters look hot, and they are. Radiant heaters are more of a fire hazard and burn danger than other types of heaters. They typically use less electricity and provide for more instant heat. Radiant heaters have a metal or quartz element that is heated, and use reflectors to send the heat to a specific location.
- Oil-filled radiators. They use the normal air flow of a room to spread the heat that they make. They take longer to warm a room, but they provide a lot of heat and they are quiet. Good for heating a cold room all the time.
- Ceramic Fan blown heaters use fans to spread the warm air. These don't get as hot to the touch as radiant heaters or oil-filled radiators.
- Heater Fan use a fan that blows air over a heated coil. They provide fast, even heat over a larger area. In addition, usually the heater portion can be turned off and the fan can be used alone in warmer weather.
So where does all this information leave me? My ceramic space heater uses 1500 watts and costs me about 18 cents an hour
to use, at 12 cents per kWh. I probably use it about 8 hours a day,
which makes it $1.44 a day. My gas bill, which covers heat, hot
water and cooking, runs about $3.50 a day when it is really cold
outside. So what makes more sense? I don't know how much I would have
to turn up the heat to make my desk area warm, and I'm not sure that I
want to find out. What are my options? (Besides freezing, of course.)
The Missouri Department of Natural Resources website probably summarizes it the best:
"If you turn your central heating system down a few degrees and
supplement the heat in a small area with a space heater, you will
probably save money.
If you do not turn the thermostat down and add more heat with the electric space heater, you will increase your total bill."
I wonder if I could turn my heat down another two degrees and use the space heater? Or put on another layer of clothes? I think I'll try both and see how it goes. I'll let you know!
Another resource: The US Department of Energy's Consumer's Guide to Portable Heaters"