I was really surprised to read in the FH Kitchens and Baths issue that electric ovens were more efficient that gas. I always thought that it worked like this: coal-burning electrical plants supply your electicity at a 30something% efficiency after line-loss,etc. so that it was almost always more efficient to just burn your fossil fuel in the privacy of your own home, rather than letting a filthy plant do it for you. does anyone know how this actually works and how electric ovens and ranges come out on top? does this apply to clothes dryers too?
I have another question about electrical efficiency. do low-voltage fixtures acfually offer greater efficiency, even when the juice their transformer is pulling is figured in? If energy consumption is a top priority, should I be getting low-voltage recessed cans instead of line voltage (price put aside, of course). and to those conservationists (of which I am one), don’t worry, my own house if about 95% CF.
thanks everone.
Replies
The efficiencies in the magazine are calculated from the gas or electricity delivered at the meter, and in that sense, electricity is more efficient.
IMO, efficiency arguments are pointless, wherever you decide to measure the input. The interesting number is BTU/$, including capital costs, upkeep, and future price changes.
do low-voltage fixtures acfually offer greater efficiency
only if you are using LEDs
junkhound--is there such a thing as a low-voltage LED? does it dim? do you know of any specific products?
thanks,
michael
Individual LEDs are typically 1.2 to 1.5 volts each. Commercial arrays are parallel series combinations. The LEDs you see on cars are 12V nominal LED arrays. I dont use any LV lighting in own house so have not researched overall availability of LEDs with LV house lighting fixture bases are available. http://www.theledlight.com/ is the first google hit for such. Pricey, $23 for 25 W incandescent equivalent, but only pulls 2.5 watts.
The space station emergency escape lighting is a string of series LED around the 'doors'. Yep, there is such a thing as emergency escape from the station, there is also a big dump valve to extinguish fires. Nothing like vacuum to put out a fire.
An electric oven is more efficient in a different way, in that it doesn't need to be vented. Especially significant for an oven in an ACed space, since the oven can be built super-insulated and thus release very little heat (except when the door is open).
Dan--
what's the ACED space that you were talking about?
what's your opinion about which is the more environmentally friendly, gas or electric?
thanks,
Michael
ACed -- Air conditoned. Any heat you put into an air conditioned space will have to be pumped out. Electric appliances, since their efficiency is so high (in terms of local energy in/out), can save a lot of money and reduce total energy consumption, CO2 production, etc, by reducing AC load.
For the average family the microwave is probably the most environmentally friendly (ignoring the foods you typically fix in it). Gas or electric conventional range doesn't make that much difference (save for the above AC issue) unless you cook more than the average family. If you cook a lot, gas is probably "friendlier" during non-AC weather conditions, electric when the AC is on.
If your view never changes you're following the wrong leader
> . . . since the oven can be built super-insulated and thus release very little heat (except when the door is open).
But doesn't that just slow down the heat exchange? The oven is still within the room envelope, and no matter how well it's insulated, the oven temp will eventually equilibrate with the room, so all that energy still has to be pumped out.
Granted, it might push a lot of that heat release into nighttime hours, where AC might not be needed.
Don
If you only use the oven for a very brief period -- just long enough to heat it up -- then you're correct. But if you're cooking the T-day turkey for several hours, for each hour of operation you release so much heat, basically a function of the temperature differential and the R value of the insulation.With our relatively new electric range you can barely tell that the oven is on when you walk by, it's so well insulated.
If your view never changes you're following the wrong leader
I see your point. While it's doing its job of cooking, it's not cycling on & off as much if it's well insulated & sealed (just as in a home heating situation).
Once you shut it off, doesn't matter how eficient it is - all the residual heat will eventually find its way out.
Don
All true.
If your view never changes you're following the wrong leader
With our relatively new electric range you can barely tell that the oven is on when you walk by, it's so well insulated
Don't forget that electric is much, much more effieicient for (residential) broiling than gas. Also, convection cooking is electric-only--and is "efficient" since only the 120V fan is running to circulate the heat until the stat kicks the heating element back on.
The cooks all swear that gas makes better baked products, but I've never been able to tell the difference (not untill you start talking commercial brick ovens, at least).
I occasionally wax nostaligc for broiling; for just broiler-toasting for that matter. With my gas oven, there's about 10 months of the year, it just gets too hot to broil anything inside of it. (no spare outlets or countertop in my 1951 kichen for atoaster over either <sigh>).Occupational hazard of my occupation not being around (sorry Bubba)
I think even most cooks prefer electric ovens, even though they're generally fans of gas cooktops.
If your view never changes you're following the wrong leader
most cooks prefer electric ovens, even though they're generally fans of gas cooktops
Well, if money were no object, and the electrical and plumbing and insulation done, then, in the kitchen remodel, it would be an electric over, for sure.
Mind you, for a cooktop, I'm of both minds, really. In my ideal world, I'd have two electric "burners" and at least two gas. Why? Because there is jsut no low simmer like you can get with electric. Boiling water? Making a decent omelette? Give me NG every time <g>.Occupational hazard of my occupation not being around (sorry Bubba)
There are fractional differences in efficiency between the various incandescent technologies, with quartz generally being a hair more efficient than regular globes. Not enough to really worry about, though.
Fluorescent is by far the most efficient "non-exotic" lighting available (after sunlight).
One thing about low-voltage cans (or track) is that you can put the light right where you want it more easily than with line voltage. The filament in an LV lamp is tiny, so it can be focused much tighter than in an 120v R30 flood (for example). A 50w MR16 puts a LOT of light in a specific place and APPEARS to be very bright, giving high color resolution and good contrast. So even though the lumens/watt ratio might not be better than the 120v lamp, I would say that it depends on the application.
If there's one thing that looks terrible to my eye, it's a 5" or 6" recessed can with a baffle or reflector trim designed for use with an R or PAR lamp, but an A-lamp or a squiggly CF is used instead. The light output is not properly reflected down and it gives a lower-intensity flat-looking general illumination that wastes a lot of useful light. Sure maybe it's using only 14 watts, but the lighting effect can be terrible.
Ed
Edited 11/10/2007 8:35 am ET by edlee