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Home > Archive > Alternative Power sources > August 2005 > Improving peltier cooler?
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Improving peltier cooler?
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| Tony Wesley 2005-08-21, 9:21 pm |
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Steve Spence wrote:
[...]
> It's a Schumacher WM-10000A 40 amp charger. I'll be discussing it on my
> blog in a couple of days, as I'm going camping tomorrow, and just
> charged my pack. I'll be running a Coleman 40 quart peltier cooler, plus
> some fluorescent lights at the site. [...]
Steve (or anyone);
Is there any way improve the efficiency of a peltier cooler? I added
some reflectix inside to boost the insulation a bit. Do you know
anything else that could help? They're power hungry.
Seems to me that a little dorm fridge will draw less power than a
peltier cooler. The cooler I have draws 4 amps @ 12 volts, 48 watts
continuious. IIRC, a little dorm fridge draws (on average) about 35
watts or less.
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| Steve Spence 2005-08-21, 9:21 pm |
| The 40 quart unit I have pulls .78 amps at 120vac. The dorm fridge pulls
1.02 amps at 120vac. The dorm fridge has a thermostat, and cycles, the
peltier runs all the time. Maybe a thermostat would drop consumption a
bit, as well as increasing the insulation.
Steve Spence
Dir., Green Trust, http://www.green-trust.org
Contributing Editor, http://www.off-grid.net
http://www.rebelwolf.com/essn.html
Tony Wesley wrote:
> Steve Spence wrote:
> [...]
>
>
>
> Steve (or anyone);
>
> Is there any way improve the efficiency of a peltier cooler? I added
> some reflectix inside to boost the insulation a bit. Do you know
> anything else that could help? They're power hungry.
>
> Seems to me that a little dorm fridge will draw less power than a
> peltier cooler. The cooler I have draws 4 amps @ 12 volts, 48 watts
> continuious. IIRC, a little dorm fridge draws (on average) about 35
> watts or less.
>
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| Bill Kaszeta / Photovoltaic Resources 2005-08-22, 2:21 am |
| Thermostats are of little help. When the power to a peltier device
is off, the peltier device easily conducts heat into the refrigerator.
Perhaps a heat pipe would help, but that is a totally different
design.
On Sun, 21 Aug 2005 19:42:11 -0400, Steve Spence <sspence@green-trust.org> wrote:
[color=darkred]
>The 40 quart unit I have pulls .78 amps at 120vac. The dorm fridge pulls
> 1.02 amps at 120vac. The dorm fridge has a thermostat, and cycles, the
>peltier runs all the time. Maybe a thermostat would drop consumption a
>bit, as well as increasing the insulation.
>
>
>Steve Spence
>Dir., Green Trust, http://www.green-trust.org
>Contributing Editor, http://www.off-grid.net
>http://www.rebelwolf.com/essn.html
>
>Tony Wesley wrote:
Bill Kaszeta
Photovoltaic Resources Int'l
Tempe Arizona USA
bill@pvri-removethis.biz
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| Kiwi John 2005-08-22, 7:21 am |
| drop the voltage going to them
try 6 volts experiment a little
"Bill Kaszeta / Photovoltaic Resources" <kaszetaw@mindspring.com> wrote in
message news:43095d58.17736768@news.west.earthlink.net...
> Thermostats are of little help. When the power to a peltier device
> is off, the peltier device easily conducts heat into the refrigerator.
> Perhaps a heat pipe would help, but that is a totally different
> design.
>
> On Sun, 21 Aug 2005 19:42:11 -0400, Steve Spence <sspence@green-trust.org>
> wrote:
>
>
> Bill Kaszeta
> Photovoltaic Resources Int'l
> Tempe Arizona USA
> bill@pvri-removethis.biz
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| nicksanspam@ece.villanova.edu 2005-08-22, 9:21 am |
| Steve Spence <sspence@green-trust.org> wrote:
>The 40 quart unit I have pulls .78 amps at 120vac.
That's the (1.33 ft^3) Peltier version, with 94 watts?
>The dorm fridge pulls 1.02 amps at 120vac.
....122 W for how many cubic feet?
>The dorm fridge has a thermostat, and cycles, the peltier runs all the time.
>Maybe a thermostat would drop consumption a bit, as well as increasing
>the insulation.
A side-by-side test with 2 K-a-W meters would be interesting. How would
these compare with the Mt. Best chest fridge, at 103 Wh/day (4 W average)?
Speaking of which, what's the most efficient chest freezer available in
the US? How does it compare with the most efficient fridge? (Dr. Chalko
at Mt. Best noticed that some chest freezers used less energy than the
best fridge, despite the greater temp diff.) Who makes a good digital
thermostat for a conversion? How can we have a small freezer compartment?
Nick
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| Steve Spence 2005-08-22, 9:21 am |
| I'm using a Radio shack pool/spa wireless digital thermometer. It's 34F
in my coleman right now, with 76F ambient.
Steve Spence
Dir., Green Trust, http://www.green-trust.org
Contributing Editor, http://www.off-grid.net
http://www.rebelwolf.com/essn.html
nicksanspam@ece.villanova.edu wrote:
> Steve Spence <sspence@green-trust.org> wrote:
>
>
>
>
> That's the (1.33 ft^3) Peltier version, with 94 watts?
>
>
>
>
> ...122 W for how many cubic feet?
>
>
>
>
> A side-by-side test with 2 K-a-W meters would be interesting. How would
> these compare with the Mt. Best chest fridge, at 103 Wh/day (4 W average)?
>
> Speaking of which, what's the most efficient chest freezer available in
> the US? How does it compare with the most efficient fridge? (Dr. Chalko
> at Mt. Best noticed that some chest freezers used less energy than the
> best fridge, despite the greater temp diff.) Who makes a good digital
> thermostat for a conversion? How can we have a small freezer compartment?
>
> Nick
>
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| nicksanspam@ece.villanova.edu 2005-08-22, 10:21 am |
| Steve Spence <sspence@green-trust.org> wrote:
>I'm using a Radio shack pool/spa wireless digital thermometer. It's 34F
>in my coleman right now, with 76F ambient...
[color=darkred]
Nick
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| nicksanspam@ece.villanova.edu 2005-08-22, 10:21 am |
| Steve Spence <sspence@green-trust.org> wrote:
>digital thermostat - http://www.smarthome.com/300600.html
What's the price and temperature range and power consumption
and power switching ability?
[color=darkred]
Nick
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| Steve Spence 2005-08-22, 10:21 am |
| aw, come on nick, that's why I gave you the url:
Load capacity of 5 A @ 30 V resistive and 2 A @ 30 V inductive
DIGITAL NON-PROGRAMMABLE THERMOSTAT Price $39.99
Temperature setting range in heating : 5° C to 30 °C (40 °F to 85
Temperature display scale : 0.1 degree
Temperature reading accuracy : +/- 0.5 °C (+/- 0.9 °F)
Would be nice if it went to 30F, but 40F is sufficient .....
Steve Spence
Dir., Green Trust, http://www.green-trust.org
Contributing Editor, http://www.off-grid.net
http://www.rebelwolf.com/essn.html
nicksanspam@ece.villanova.edu wrote:
> Steve Spence <sspence@green-trust.org> wrote:
>
>
>
>
> What's the price and temperature range and power consumption
> and power switching ability?
>
>
>
>
> Nick
>
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| nicksanspam@ece.villanova.edu 2005-08-22, 3:21 pm |
| Steve Spence <sspence@green-trust.org> wrote:
>Load capacity of 5 A @ 30 V resistive and 2 A @ 30 V inductive
>DIGITAL NON-PROGRAMMABLE THERMOSTAT Price $39.99
>
>Temperature setting range in heating : 5° C to 30 °C (40 °F to 85
The Smart Home people told me 32-122 F. Which is correct?
>Temperature display scale : 0.1 degree
>Temperature reading accuracy : +/- 0.5 °C (+/- 0.9 °F)
>
>Would be nice if it went to 30F, but 40F is sufficient .....
....34 or 36 would be nice. Maybe we need a small resistor in series
or a large resistor in parallel with the thermistor.
The AUBE TH-135 is a heat-only thermostat (open on temp rise.) The -141,
144, 147 and 148 are for heating or cooling. The -135 uses 2 AAs for power.
The 144 can work with a remote sensor, which might save unsoldering the
thermistor from the board and adding a twisted pair cable. Aube is near
Montreal, at http://www.aubetech.com, 800-762-2823.
It would be nice to have a small freezer compartment for ice cubes and
ice cream. Can we find an extremely efficient chest freezer model at
a reasonable price and make an insulated new small freezer compartment
around the original stat and the cold coils and set the freezer stat for
10 F and add a small fan to circulate air between the new compartment
and the rest of the chest when the digital stat says the chest is above
36 F. Or just insulate the original thermostat bulb and cold coils and
blow chest air past them when the new stat says the chest is above 36?
What's the most efficient reasonably-priced chest freezer available
in the US? Can we find one with exposed hot coils, vs coils under the
skin, so we can add more foamboard insulation? How would it compare
with the most efficient fridge?
Nick
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| James Storm 2005-08-22, 10:21 pm |
| nicksanspam@ece.villanova.edu wrote:
> Steve Spence <sspence@green-trust.org> wrote:
>
>
>
>
> That's the (1.33 ft^3) Peltier version, with 94 watts?
>
>
>
>
> ...122 W for how many cubic feet?
>
>
>
>
> A side-by-side test with 2 K-a-W meters would be interesting. How would
> these compare with the Mt. Best chest fridge, at 103 Wh/day (4 W average)?
>
> Speaking of which, what's the most efficient chest freezer available in
> the US? How does it compare with the most efficient fridge? (Dr. Chalko
> at Mt. Best noticed that some chest freezers used less energy than the
> best fridge, despite the greater temp diff.) Who makes a good digital
> thermostat for a conversion? How can we have a small freezer compartment?
>
> Nick
>
A company called RANCO makes a digital #ETC-111000-000 for refrigeration
use. It can also be set up for heating. -30 to 220. A little probe on
the end of a wire for remoting. Adjust set point and check temp from
outside of box. I think it can switch a small fridge with no problem.
Johnson has #A419 and is the same thing rated for 15amps 120/240.
Either can be bought for around $50.00.
--
James Storm
aka Stormy Weather
jstorm@ptd.net
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