What do I need to power an Electric Blanket?
A Real
blanket for 7-8 hours a night? I cant seem to find how many watts an EB
uses. Could it be run dirrectly off a battery or do i need a small
inverter? Basically, what do I need to do that? Thanx for any info.
Steve Spence
say the blanket is 400 watts. times 8 hours a night, that's 3200 watt hours.
If you get 4 hours of sun per day, you will need at very minimum, best case
scenario, 800 watts of pv (actually quite a bit more than that). you will
need a 533 amp hour battery bank, and a 500 watt inverter. This assumes the
sun shines each dat and the batteries are brought up to full charge.
A extra blanket and a SO are a better deal.
--
Steve Spence
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"A Real" <Le_...@webtv.net> wrote in message
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danny burstein
>you will need a battery, as the sun does not shine at night.
>say the blanket is 400 watts. times 8 hours a night, that's 3200 watt hours.
>If you get 4 hours of sun per day, you will need at very minimum, best case
>scenario, 800 watts of pv (actually quite a bit more than that). you will
>need a 533 amp hour battery bank, and a 500 watt inverter. This assumes the
>sun shines each dat and the batteries are brought up to full charge.
>A extra blanket and a SO are a better deal.
Ah, but between food costs and vet visits, etc., you'll be paying at least
a few dollars/day for any dog worthy of the name. Probably more.
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_____________________________________________________
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Marty Roth
probably get one for free from the pound. You'd be surprised how much heat
a 60 lb. hound throws off.
"A Real" <Le_...@webtv.net> wrote in message
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Steve Spence
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"danny burstein" <dan...@panix.com> wrote in message
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danny burstein
>your dog is your "Significant Other"? ;-)
Nah, I share accomodations with a cat. Much more civilized, but not very
high in the heat radiation count.
Nelson
My electric blanket is rated at 170 watts if I remember correctly.
With rounding up, that translates to about 1.5 amps at 120VAC... 12Amp
hours...
which comes to 144 Ah at the battery. For headroom, I'd want about
300 amp hours capacity at the battery.
You'd need an inverter... the blanket would possibly work, but not
very well, at the lower voltage, and the controller might not work at all.
The blanket I have is thermostatically controlled, so it's not drawing all
the time. That would reduce the consumption figures above, which assume
constant operation.
For what it's worth, I use one the first night for a couple of hours
when
I go to the cabin in the winter and the place is still warming up. The bed
is the SLOWEST thing to defrost! After the first couple of hours, the
blanket is not needed 'til the next time we come.
You could test your blanket with an ammeter, or check labelling on the
control to see if there's a difference in yours.
Sizing the panel depends on how often you'd use the blanket, and local
weather (e.g. sunhours/intensity, etc) wherever you are.
Anybody else weigh in on this?
Nelson
"A Real" <Le_...@webtv.net> wrote in message
news:24333-3E...@storefull-2358.public.lawson.webtv.net...
Antonio VELA VICO
--
Saludos desde www.solener.com
Antonio Vela
"Steve Spence" <ssp...@green-trust.org> escribió en el mensaje
news:gbN9a.23320$gf7.5...@news4.srv.hcvlny.cv.net...
Grizzman
Steve Spence
400 watts at 120 volts is 3.33 amps
400 watts at 12 volts is 33.3 amps
Still needs the same amount of pv and batteries, just saves $200 buck on the
inverter.
--
Steve Spence
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"Grizzman" <grizzma...@acsalaska.net> wrote in message
news:v6r10j2...@corp.supernews.com...
Daren Webster
> If a cold bed is your problem, I suggest just sleeping with a dog. You can
> probably get one for free from the pound. You'd be surprised how much heat
> a 60 lb. hound throws off.
A 60 lb dog..............COME ON.. what about a 115 pound woman? They
throw off some serious heat. But cost of operation, budget, housing,
clothing, arguing, feeding, blah, blah, blah......maybe the dog is a
better deal!
Ralph Kuhn
you could just use a decent comforter, or a good friend.
flexy
...
> > > In <YLK9a.19874$gf7.4...@news4.srv.hcvlny.cv.net> "Steve Spence"
> > <ssp...@green-trust.org> writes:
> > >
> > > >you will need a battery, as the sun does not shine at night.
> > >
> > > >say the blanket is 400 watts. times 8 hours a night, that's 3200 watt
> > hours.
> > > >If you get 4 hours of sun per day, you will need at very minimum,
best
> > case
> > > >scenario, 800 watts of pv (actually quite a bit more than that). you
> will
> > > >need a 533 amp hour battery bank, and a 500 watt inverter. This
assumes
> > the
> > > >sun shines each dat and the batteries are brought up to full charge.
> > >
> > > >A extra blanket and a SO are a better deal.
> > >
> > > Ah, but between food costs and vet visits, etc., you'll be paying at
> least
> > > a few dollars/day for any dog worthy of the name. Probably more.
> > >
> > >
> > > --
> > > _____________________________________________________
> > > Knowledge may be power, but communications is the key
> > > dan...@panix.com
> > > [to foil spammers, my address has been double rot-13 encoded]
> >
> >
>
>
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Marty Roth
waste it. Since no form of energy is totally renewable, conservation should
always be addressed.
"Antonio VELA VICO" <sol...@teleline.es> wrote in message
news:b4iurc$20pa3k$1...@ID-174113.news.dfncis.de...
Slow Joe
wrote:
>Seriously, just because it's renewable energy, that doesn't mean you can
>waste it. Since no form of energy is totally renewable, conservation should
>always be addressed.
>
If you put the electric blanket under two other blankets and a foam
layered coverlet, then the electric blanket doesn't need much power at
all. I do that plus I leave the blanket thermostat on the lowest
setting, with a timer so it only runs from 2am to 5am.
regards,
Joe
Marty Roth
"Slow Joe" <nos...@dont.bother> wrote in message
news:3e6f3134...@news.wfeca.net...
Scott
wrote:
A 60 lb dog throws off a lot more heat than a 115 lb woman (higher
metabolism) and (more importantly) a 60lb dog won't bitch when you
stick your icy cold feet against him (or her) to get warm.
It also won't bitch at you for getting drunk, driving the pickup truck
in the ditch (again) or even (if you are so inclined) sleeping with
her sister.
The difference between a redneck and a hillbilly: a hillbilly says
"Man, it's cold - better throw another log on the fire." A redneck
says "Man, it's cold - better throw another dog on the bed..."
ro...@mauve.demon.co.uk
> that doesn't help.
>
> 400 watts at 120 volts is 3.33 amps
> 400 watts at 12 volts is 33.3 amps
>
> Still needs the same amount of pv and batteries, just saves $200 buck on the
> inverter.
But with the inverter, it'll be drawing over 37A or so from a 12V battery,
and wasting 10% or so of the power.
--
http://inquisitor.i.am/ | mailto:inqui...@i.am | Ian Stirling.
---------------------------+-------------------------+--------------------------
Money is a powerful aphrodisiac, but flowers work almost as well.
-- Robert A Heinlein.
Steve Spence
but this application will work fine on a dirty, efficient inverter. 12 volt
electric blankets are harder to find, and more expensive, usually. that
amount of current draw would require large cables from the battery to the
bed. with the inverter, the big cables are shorter, reducing power loss.
--
Steve Spence
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<ro...@mauve.demon.co.uk> wrote in message
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Roger Riordan
>that doesn't help.
>
>400 watts at 120 volts is 3.33 amps
>400 watts at 12 volts is 33.3 amps
>
>Still needs the same amount of pv and batteries, just saves $200 buck on the
>inverter.
The resting human body dissipates about 60 watts. With adequate installation
that's enough to keep you warm on the coldest night. An electric blanket can
fullfill three requirements:
1. It can warm up the bed for you before you get in.
2. It can compensate for moderate deficiencies in the insulating properties of
the bedding. For example, on our bed, one blanket is optimum for a temperature
in the bedroom of 19 degrees C, while two blankets are optimum for 15 degrees C.
So if the air temperature is 17 degrees C., or the temperature falls during the
night, the electric blanket can make up the difference.
3. It can keep the parts of the bed away from your body comfortably warm, so
that if you roll over, or move your feet, you don't encounter icy bedding.
Only an over blanket can fulfil all these functions. An under blanket can warm
the bed, but if you leave it on, your underside will be too hot, and the top
part of your body too cold.
400 watts is far more than is needed for any of these functions. I have a dual
control over blanket with a maximum rating of about 40 watts per side. The
wires are spaced about 1 inch apart, and on each side there is a thermistor
sensing element between the wires, roughly over the chest. The controller
attempts to keep this at an individually adjustable preset temperature. This
power is a bit low for preheating the bed -- it takes about an hour to get the
bed really warm on a cold night, but it is adequate for functions 2 and 3.
This arrangement works very satisfactorily under normal conditions, but it
cannot compensate for grossly inadequate bedding. Under these conditions you
feel hot and cold simultaneously -- hot immediately below the wires, and cold
between them. A blanket which gave a more even distribution of heat would
probably overcome this problem, but it is much more desirable environmentally to
put on another blanket.
Roger Riordan AM
Steve Spence
money than a 400 watt blanket. I still don't believe this is a good
application for solar.
--
Steve Spence
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"Roger Riordan" <rio...@mira.net> wrote in message
news:e6727v0h5tb8v20v2...@4ax.com...
Anthony Matonak
>
> A 40 watt electric blanket could be powered by a solar panel for much less
> money than a 400 watt blanket. I still don't believe this is a good
> application for solar.
Perhaps it would work better to have a water bed half-filled with a
phase change material and a heat exchange coil that is hooked to a
solar water heating panel. This would provide a warm bed for many
nights without sun and yet still get "charged" by sunlight.
Anthony
Marty Roth
but not too hot.
"Anthony Matonak" <res0...@gte.net> wrote in message
news:3E7153AF...@gte.net...
mikell
mikell
Roger Riordan
>Or, maybe a bed filled with a radioactive isotope. Something that's hot,
>but not too hot.
Low running cost -- if you ignore the cost of chemotherapy -- but very hard to
regulate. And the life of the bed is likely to be a lot more than that of the
occupant.
Roger Riordan AM