220 volt baseboard heater efficiency

More efficient than a 110 volt plug-in heater?

Would a 220 volt baseboard heater save me energy, compared to the two 110 volt plug in heaters I'm currently using to heat our kitchen addition? My husband claims it will but I can't see why. Are 220 volt heaters more efficient? Are baseboard heaters more efficient than plug-in heaters?.

Answer from Green Energy Efficient Homes

You're absolutely right, you won't get any improvement in efficiency by switching from 110 volt plug in heaters to 220 volt baseboard heaters. The advantage of a 220 volt heater is that it can provide greater heat output in terms of the BTU or watts it puts out, than a typical plug-in 110 volt heater. That is mainly because 220 volt heaters are installed on dedicated circuits that have enough amperage (usually 20 or 30 amps) so they can convert more electrical power to heat. But for a given amount of heat output, the baseboard heater will consume exactly the same amount of electricity as two plug-in 110 volt heaters.

Watts can be used to measure both the capacity of an electric heater (amount consumed at any given time - for example, a 1500 watt heater) or its electricity consumption (amount consumed over a time period, for example 1.5 kilowatt hours for a 1500 watt heater running at full blast for an hour). 110 volt circuits are usually wired for 20 amps (sometimes 15 in older houses). Since Watts = amps x volts, a 15 amp circuit x 110 volts can handle a 1650 watt load, so a 1500 watt heater can safely be plugged into such an outlet. Compare this to a typical 220 volt circuit installed for baseboard heaters. Even if wired at 20 amps such a circuit could actually handle 20 amps x 220 volts or 4400 watts of power; more often the circuits for a 220 volt baseboard heater are wired at 30 or 40 amps, which means they can handle significantly higher power output. This is why you can get a lot more heat out of a 220 volt baseboard heater.

Your husband is mistaken if he thinks that a 220 volt baseboard heater of a given wattage is more efficient than a 110 volt heater of the same wattage just because it draws a lower amperage. If they have the same wattage they produce the same heat output for the same electrical input.

Because any electrical resistance heater is 100% efficient at converting electricity into heat (there is no other work the electricity can be put to in an electric heater, other than producing heat), either choice will cost about the same in terms of electricity consumption. My page on Energy efficient electric heaters explains this efficiency issue in more detail.

Whether you change to a 220 volt heater or not is therefore a question of aesthetics, capacity, or other issues, not energy efficiency. If you don't want the clutter of two bulky space heaters in your kitchen addition, a baseboard heater will reduce that bulk significantly and you'll eliminate the risk of knocking a space heater over by accident (although many modern space heaters come with an automatic shutoff if they are toppled). If the two space heaters are doing an adequate job alread you won't need the extra capacity of a 220 volt heater, but if they are struggling to keep the room warm, a 220 volt baseboard heater will help. The other thing to consider is that installing a 220 volt heater requires extra wiring and an extra 220 volt circuit on your breaker panel, which can add significant costs if you hire an electrician to do the job. (If you're handy yourself and have experience doing wiring, it's not that difficult a job, but be sure to understand the risks first.)

Of course, the most energy efficient solution is to find a way to avoid using any kind of electrical heater, since electrical heat is the most expensive form of home heating. Anything you can do to improve insulation levels in your addition will help. In our house we had a kitchen addition that was built in 1995 and to keep costs down the owners at that time just installed a 220 volt baseboard heater on an outside wall. That was cheaper than running an extra duct from the furnace main. When we replaced the furnace in 1998 we got the installers to run an extra duct through the crawl space (insulated, of course) and out the addition floor, and we were able to remove the baseboard heaters and stay comfortable. Later on I thoroughly insulated the crawl space walls, and that reduced the amount of heat escaping out the floor, which allowed us to close off the addition vent and still stay warm. Finally, in 2010 we tore down the addition and built a full-width addition (10x20 feet) and because we made sure it was very well insulated, it stays plenty warm there even on -20F days, without any extra electric heaters or even an extra forced air heating register.

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