Electric heaters
Friday, April 10th, 2009Jeff,
Thank You very much for your help [with my sump pump question]. I will start looking at other energy users in the house. Maybe I am overlooking something.
I do have an “Eden Pure” electric heater, but it says it won’t use much energy at all. What is your opinion of those?
Thank You,
Arnie
Arnie,
I get this question 10 times a week. All these electric heaters have claims like they will heat your house for pennies a day, or only use the same power as a coffee pot. Here is the dirty little secret of the first law of thermodynamics – They are all the exact same efficiency. There is no difference in how well they can heat anything and I defy any manufacturer to prove me wrong.
Any electric heating coil is considered 100% efficient since all thermal losses of burning fuel occurs at the power plant and during power transmission before the electricity gets to your electric meter, so there are no combustion losses like you would have in a oil, wood, or gas fired heater. All the electrical energy going into any electric heater (not counting a heat pump compression cycle) is turned into heat. The heat content of a kWh of electricity is 3,413 BTU per hour.
This means for every kWh of electricity that goes into the electric heater’s power cord, you will get 3,413 BTU per hour of heating coming out. Of course, if a heater has a fan it might blow this heat out more than a heater without a fan, but it does not matter if the heater has a radar shaped reflector, a fan, or fake fireplace logs, all you get out is what goes in.
Now as for claiming they only use the same electricity as a coffee pot, this may be true. However, your coffee pot only boils water for 5 minutes a day then turns off. Try this: As soon as the coffee pot heats the water to boiling, empty it into a big bucket so the heat can disperse into the room and refill with cold water. Do this all day long and see how much power that takes. This is how long those little heaters would need run to heat a cold house.
Yes, if you stand in front of one of those heaters you will feel warm and they will heat up a room, but a typical home will have a central furnace in the 85,000 BTU/H or higher capacity, and that means it would take a lot of “coffee pots” to provide the same amount of heat required to heat a home.
I have one of these fake fireplaces in a sun room that has great winter window views, but its too cold to sit out there without a little heat, so we use our fake fireplace to heat it a few hours every few days, but I am not expecting it to heat my entire house and believe me, it really spins the electric meter when it runs.
Hope this helps,
Jeff Yago
