Among fans of energy efficiency, electric space heaters present something of a paradox: The are inefficient by nature, but they do warm you—quickly and well. The energy efficient electric space heater is at once a myth and a reality. Here's why:
It really depends on how you use an electric space heater, and whether it's a good idea in your particular situation. Let's say you live in a drafty old house in a cold climate. Heating the whole house with an electric space heater would, of course, be just plain silly. Tossing pebbles at the Goliath that is Old Man Winter.
But say you live in a drafty old farmhouse in a cold climate, the kids have gone to college, and you work from home in a study on the first floor. You're working on re-insulating the house and sealing up all the air leaks but haven't gotten there quite yet. And for now you just want to keep warm while you work. You turn down the thermostat, close the doors of your home office and turn on your sleek little electric space heater. Switch on the computer. Have a sip of coffee. Perfect.
Comments
Strikes me as a bit of a weak article. No facts or figures? Just a cosy vision to sell a product, come on! Stick some extra clothes on and leave the heater off too!
Posted by David Lockie on Feb 10, 2010 1:29pm@ David -- Thanks for the comment; my intent with this piece wasn't (if it isn't obvious) to provide a comprehensive evaluation of the economics of space heaters, but I think it is accurate to say that their effectiveness certainly depends on how they're used. With so much bad information out there (a quick google search brings up the meta description for one page as: "Energy efficient space heaters will usually keep a home's heating bill low during the winter" -- which is certainly not true), I think it's important to balance both sides of the story. While I'd hate to see a homeowner wasting money on a scam (on a site, for example, like that quoted above), I'd also hate to see space heaters get a bad reputation because of such scams.
Anyway, I, personally, am cozied up in several layers of flannel, and have turned off my space heater for the day. Maybe I'll write a post about that tomorrow :-)
Thanks again for the comment, and glad you checked out the post.
Posted by Will on Feb 10, 2010 3:25pmIt's probably true that occassional use of an electric fan heater is probably better than permanently heating the whole house, but remember that about 60-70% of the energy used to make electricity is lost at the power station. Until a significant proportion of our electricity comes from renewables, electricity is still quite "dirty".
And even the best electric fan heater is only 100% efficient, of course. A heat pump (i.e. air conditioning with the cold part outside and the warm part inside) can produce (well, move) over 4 times as much heat energy as the electric energy it consumes! :)
Posted by OrangeJon on Feb 10, 2010 8:04pmWill -
You were describing exactly my scenario - home alone all day working in my office. And I was going with the space heater solution, but now am wondering - which is really more efficient? Can you quantify our gut feelings with some hard data?
Posted by Rick Dickinson on Feb 11, 2010 1:27pmWill -- great post about energy efficient space heaters.
I think it is an oxymoron indeed!
@OrangeJon is right about electricity; a watt of electricity delivered to your house was generated by digging up coal (typically), putting it in a train, delivering it to an electricity generating plant, boiling water to turn a turbine at which point we have some electricity ... and THEN the loss OrangeJon talks about occurs as the electricity is transformed up, down, and into the 120V used by a space heater. Compared to burning natural gas or oil, delivered directly to your house, electricity is a terrible way to make heat; my gas burner is allegedly 80% efficient.
However, even if electricity has losses in the process of getting to your house, I think part of the notion here is that if you're heating a small room instead of the whole house, you're still probably winning from a total energy standpoint, or at least the Energy Star folks recommend electric space heaters for supplemental heating
So now the question is: which heater?
While it's true that electric heaters are 100% efficient at turning electricity into heat, not all heaters are created equal -- what you want is to feel warm, and the Vornado space heater I have seen was pretty amazing because it has enough information to put the heat where you need it, and not where you don't.
I have a pretty standard electric heater and all it does is make a lot of noise and heat up a little area in front of it. I could run the thing all day and have a hot back and cold feet.
So if the Vornado Vortx space heater runs for a shorter time to achieve the goal of comfort, it's more energy efficient indeed.
Posted by tomharrisonjr on Feb 11, 2010 6:10pmGood thread all.
@David Lockie. Point taken about data. In defense of Will, he also gets criticized for being too detailed and technical.
@OrangeJon--thanks for pointing out the losses in and source energy for electricity--absolutely right and should be part of the consideration.
Here's my situation:
My home office is in a mostly bare concrete basement, with our least efficient windows, and an uninsulated ceiling. It retains heat for about 20 minutes. It's primary source of heat is a short stub of our oil fired hot water baseboard system that was only intended to prevent pipe freezing. On a typical Maine winter day, it's at 52 to 55 degrees. I proudly wear a sweater or fleece everyday, but I can't type at that temperature. Typing is pretty much what I do all day.
Our plumber estimates $1500 to put in a new zone and properly heat this space by extending the baseboard. Since we're planning to move our office to the Mallett Deep Energy Retrofit project as soon as it's done, and this room will return to being a...basement, that's a capital investment that won't pay off. I evaluated a direct vent propane heater that was $900 before installation. I thought about wood, but that got very expensive after the stove purchase and 3 stories of pipe before thinking about fuel.
So I am typing this comment at 64 degrees with the heat provided by the Vornado Vortex....gasp, electric heater. To be sure, it pains me that the Basement Outlet circuit on our eMonitor, because of this 1500 watt device, comprises 46.2% of our electricity use for the last 14 days. And that my heat needs are costing us $2 on a typical day.
But, given my particular situation, this is the rational product. Capital cost: $187. It heats me, not the rest of the room that has no other humans in it. I keep the remote next to my keyboard, and if it ever gets to the set temp of 67, it cycles off the heat. Perhaps most importantly, it is never on when I'm not in my seat.
Posted by Peter Troast on Feb 11, 2010 7:29pmAs much as I hate to admit it, there is a place for an electric space heater at our house. The fact that it is a Vornado Vortex makes me feel better. It's light enough that we actually move it from attic to back room, as needed. Without it, the back room of our house would be unusable on cold days, and the office on the 3d floor would be cold typing. Because it heats to the controller and clicks off when it reaches temperature, the Vortex makes sense for us. It's absolutely not the most efficient option. Tearing out the drywall and insulating would be much better. But we're not going to do that this week. This is a good alternative that is cost efficient, focused, and frankly luxurious.
Posted by Anonymous on Feb 16, 2010 9:38pmWill, great post. Peter's situation with his electric heater inspired me to do a very basic cost/benefit analysis of heating with natural gas vs. an electric space heater (though it may be too in depth for the casual blog reader).
http://blog.mapawatt.com/2010/02/18/electric-space-heaters/
I think there definitely are benefits to the electric space heater if used in moderation. The thermostat on the unit is also crucial.
Posted by Chris Kaiser on Feb 19, 2010 11:57pmElectric heating is THE MOST efficient way to create heat. Almost 100 % of the current from the grid is transferred into heat from the elements (in this fan's case it also powers a small fan)... Natural gas efficiency ranges from 80%-96% efficiency and oil is even lower, and that does not take into account the energy used in producing refined gas/oil. What you describe is a question of COST efficiency. If electricity was cheaper, it would be the most efficient method of heating a space.
Posted by Anonymous on Apr 1, 2010 9:53am