Date: Tue, 10 Dec 2013 15:12:08 -0500
Reply-To: Edward Maglott <emaglott3@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Edward Maglott <emaglott3@GMAIL.COM>
Subject: Re: [OT] Efficiency of electric heaters?
In-Reply-To: <BAY404-EAS322E45963C61DC680E81B76A0D30@phx.gbl>
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Here's an energy cost calculator I've enjoyed over the years:
http://www.hearth.com/econtent/index.php/articles/fuel_cost_comparison_calculator/
I have a high efficiency forced air gas furnace. The un-insulated
ducts for it run through unheated basement though. I also have my
electric service on "time of use metering." So depending on the time
of day and day of week my electricity is either about $.16/kwh or
$.06/kwh. At the low electric rate, that was cheaper last time I
checked, including a little fudge factor for loss through those
ducts. I have a portable heat pump thing that claims to get 12,200
BTU out of 9.7amps. It connects to a window to use outside air for
it's heat exchange. So that's an even better deal for btu/electric
watts. btw, over the long term, I save about 23% on my electricity
with the time of use metering.
Edward
At 05:37 PM 12/9/2013, you wrote:
>Depending where you live electric heat can be extremely expensive or
>reasonable. Here on Long Island we pay close to $0.20/kwhr. However, with
>oil near $4.00/gallon it may not be a bargain. One kwh of electric heat
>produces ~3,412 Btu/hr. of heat. 100,000 Btu/hr. requires 29.31 kw/hr. If
>you are paying $0.10/Kwh that 100,000 btu/hr. only costs $2.91. A gallon of
>fuel oil is ~138k/btu. So you would need .7246 gallon to produce 100,000
>btu. Now consider that even if you were to get 85% efficiency you really
>need .853 gallons. At $4.00/gallon that same heat in oil really costs $3.40.
>Add the cost of the pumps, blowers, controls, equipment investment and
>maintenance oil heat may not be a bargain. To compare natural gas heat look
>at your bill. Likely you are looking at some cubic feet or therms number.
>Both equate to about 100,00 btu. Gas is usually more efficient especially
>with modern equipment so maybe use 90% as your efficiency factor. Buying a
>new home you want gas heat. As for propane that gives about 96,000
>btu/gallon. Also use 90% for your efficiency and do the math from there.
>
>The trick of using portable electric heaters for most is the ability to keep
>the whole house cooler and just heat the room(s) that need a bit extra or
>only when they are occupied. As for which ones work best it does come down
>to preference and intended use.
>
>Dennis
>
>-----Original Message-----
>From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
>Dick Wong
>Sent: Monday, December 9, 2013 1:01 PM
>To: vanagon@GERRY.VANAGON.COM
>Subject: Re: [OT] Efficiency of electric heaters?
>
>Yes, 1500W in an electric heater is 1500W. The units is sitting inside the
>room, so all the heat that is generated, whether it is blown out with the
>fan, radiated into the room, heated by an inefficient fan motor or is coming
>off of the overheated power cord ;-), still contributes to the room.
> If your room is drafty, poorly insulated or has a very high ceiling, the
>air that is heated is short lived or floats away. The fan units primarily
>heat the air. The radiant units primarily heat the objects (people). The
>radiator (oil) style devices do a combination of both (and can be slow to
>get going).
>
>You may feel warmer (or at least the one or two body parts) when you are in
>front of the radiant heater, but as soon as you move away, it's gone.
> Since the fan units heat the air, the whole room feels warmer, but it takes
>longer to heat all of that air. A radiant heater gives you localized
>heating, i.e., hot spots.
>
>That's my story and I'm sticking to it. :-)
>
>Stay warm in Oregon. It's cold here in the mid-section of California too.
>
>-Dick-
>87 Vanagon Syncro (Blaze)
>
>
>On Mon, Dec 9, 2013 at 9:34 AM, Larry Alofs <lalofs@gmail.com> wrote:
>
> > The electrical energy 'consumed" by the fan also ends up as heat.
> >
> >
> >
> > On Mon, Dec 9, 2013 at 12:31 PM, Jeff Palmer <jpalmer@mymts.net> wrote:
> >
> > > I would say this is on topic. Lots of us use electric heaters to
> > > supplement. Much cheaper than Propex :) My two cents from a guy
> > > living in -30 weather:
> > > Electricity is 100% efficient (or close) regardless of the fixture,
> > > but
> > it
> > > may or may not be price competitive with less efficient heaters that
> > > use different fuel. I think?
> > > I prefer radiant heat - much more comfortable and stable. And
> > > quiet. I would think the nasty fan on some electric heaters must
> > > consume extra
> > power
> > > too. Love my oil filled unit.
> > > Jeff
> > > > Date: Mon, 9 Dec 2013 07:59:19 -0800
> > > > From: camping.elliott@GMAIL.COM
> > > > Subject: [OT] Efficiency of electric heaters?
> > > > To: vanagon@GERRY.VANAGON.COM
> > > >
> > > > Hi all,
> > > >
> > > > (This is not Vanagon-related but I don't know another pool of
> > > > engineers and scientists to write to, so I'm writing here for
> > > > help.)
> > > >
> > > > It's pretty cold here in Bend, Oregon, and the house that her son
> > > > is renting is colder than he'd like. It's an older house, built
> > > > cheaply, and only has electric baseboard heaters -- no gas, no
>fireplace.
> > > >
> > > > Mrs Elliott has been looking at electric heaters and asks whether
> > > > some put out more heat than others. "1500 Watts is 1500 Watts,
> > > > same BTUs" I
> > > sez.
> > > >
> > > > I sez, "It doesn't matter whether the heating elements are fifteen
> > > > one-hundred Watt light bulbs, or whether the heating elements are
> > > > put
> > in
> > > > an oil bath; it doesn't matter whether they write the words `infrared'
> > > > or `quartz' on the enclosure: you'll put the same heat into the room.
> > > > All heaters are alike in terms of heat output.
> > > >
> > > > "Sure, an infrared heater can be `aimed' directly at your body,
> > > > which
> > is
> > > > real nice; and others have blowers that can direct the heated air
> > > > and stir the air to keep the colder air from pooling on the floor,
> > > > but in terms of how warm the overall air in the room eventually
> > > > gets, all 1500 Watt heaters are the same."
> > > >
> > > > That's what I sez. But she knows I'm a bit of an idiot sometimes
> > > > and is tempted by expensive 1500 Watt heaters, thinking there must
> > > > be a reason why they promote this quartz or that oil-filled
> > > > feature. She points out that when you turn off an oil-filled
> > > > heater, it still radiates heat for quite some time afterwards; I
> > > > point out that the slow cooling is
> > matched
> > > > by slower warming.
> > > >
> > > > Can the engineers and scientists in the room comment on this
> > > > matter? So that This Marriage Can Be Saved? If I'm wrong, I'm wrong.
> > > >
> > > > (Probably don't want to clutter up the list with this, please
> > > > email to me directly.)
> > > >
> > > > --
> > > > Jack "Rocket j Squirrel" Elliott
> > > > 1984 Westfalia, auto trans,
> > > > Bend, Ore.
> > >
> > >
> >
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