How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.

"Bob La Londe" wrote in message
...
How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.

I've used them quite a bit, cooling optics, built a small environmental
chamber etc. Without qualifying it with numbers I'd say you would be wasting
your time trying to use peltiers to cool air for your pcs. Would using a
very small thru wall compressor aircon unit be possible? They are quite
inexpensive.

"Dennis" wrote in message
. au...

"Bob La Londe" wrote in message
...
How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.

I've used them quite a bit, cooling optics, built a small environmental
chamber etc. Without qualifying it with numbers I'd say you would be
wasting your time trying to use peltiers to cool air for your pcs. Would
using a very small thru wall compressor aircon unit be possible? They are
quite inexpensive.

My shop is 3000 square feet. About the only thing I can think of might be
to use an equipment cabinet and a small AC unit on it. Seems pretty
inefficient.

On 02/21/2011 07:38 PM, Dennis wrote:
"Bob La wrote in message
...
How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.

I've used them quite a bit, cooling optics, built a small environmental
chamber etc. Without qualifying it with numbers I'd say you would be wasting
your time trying to use peltiers to cool air for your pcs. Would using a
very small thru wall compressor aircon unit be possible? They are quite
inexpensive.

I second that -- Peltier devices are really inefficient coolers (they
make good warmers, though). Their biggest advantage is their
simplicity, but your application is a bit big to really make use of that.

Maybe put the cold side in a plenum, with a cold air duct running to
each machine? Or just make damn sure that you've got lots of airflow
past all your controllers, to get the most cooling out of the air you have.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

"Tim Wescott" wrote in message
...
On 02/21/2011 07:38 PM, Dennis wrote:
"Bob La wrote in message
...
How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.

I've used them quite a bit, cooling optics, built a small environmental
chamber etc. Without qualifying it with numbers I'd say you would be
wasting
your time trying to use peltiers to cool air for your pcs. Would using a
very small thru wall compressor aircon unit be possible? They are quite
inexpensive.

I second that -- Peltier devices are really inefficient coolers (they make
good warmers, though). Their biggest advantage is their simplicity, but
your application is a bit big to really make use of that.

Maybe put the cold side in a plenum, with a cold air duct running to each
machine? Or just make damn sure that you've got lots of airflow past all
your controllers, to get the most cooling out of the air you have.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html



Like Tim said - airflow is cheap, alternatively what about one of those
compressed air powered air coolers - hot air out one port / cold out the
other?


Not sure what their air consumption is like or what air supply you have
available..........

A practical approach might involve placing the PCs in a closed cabinet
(insulated if it's metal) with the PC PSUs and the peltier power supply on
the outside of the cabinet.

The peltier(s) mounted to thermally-isolated heatsink(s) (isolated from the
cabinet walls, if metal) on/thru an external surface of the cabinet would
need to be able to exceed/extract the heating capacity of the CPUs and
memory sticks, mainly, without the added heat load of the PSUs.

The PC case fans would likely provide adequate internal air circulation if
the cabinet's internal dimensions are reasonable (not excessively
oversized).

Got a small/medium sized refrigerator?

Liquid cooled CPU heatsinks have been around for quite a few years. One
problem might be condensation of humidity if the heatsink is cool.

--
WB
..........


"Bob La Londe" wrote in message
...
How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.

On Mon, 21 Feb 2011 20:51:04 -0700, Bob La Londe wrote:
"Dennis" wrote ...
"Bob La Londe" wrote ...
How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.

I've used them quite a bit, cooling optics, built a small environmental
chamber etc. Without qualifying it with numbers I'd say you would be
wasting your time trying to use peltiers to cool air for your pcs.
Would using a very small thru wall compressor aircon unit be possible?
They are quite inexpensive.

My shop is 3000 square feet. About the only thing I can think of might
be to use an equipment cabinet and a small AC unit on it. Seems pretty
inefficient.

An old watercooler to make chilled water, plus a small radiator
(eg transmission cooler) can be fairly compact. See eg picture at
http://www.overclock.net/water-cooling/582342-transmission-cooler-pc-3.html
and google search with: water cooled computer

--
jiw

Bob La Londe wrote:
How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.

how hot is "hot"?

On 02/21/2011 09:07 PM, Wild_Bill wrote:
A practical approach might involve placing the PCs in a closed cabinet
(insulated if it's metal) with the PC PSUs and the peltier power supply
on the outside of the cabinet.

The peltier(s) mounted to thermally-isolated heatsink(s) (isolated from
the cabinet walls, if metal) on/thru an external surface of the cabinet
would need to be able to exceed/extract the heating capacity of the CPUs
and memory sticks, mainly, without the added heat load of the PSUs.

The PC case fans would likely provide adequate internal air circulation
if the cabinet's internal dimensions are reasonable (not excessively
oversized).

Got a small/medium sized refrigerator?

Liquid cooled CPU heatsinks have been around for quite a few years. One
problem might be condensation of humidity if the heatsink is cool.

I don't know that separating the PSU from the computer is going to help
all that much -- even a crappy switching supply (which is what PC PSUs
are) is better than 80% efficient -- which means that for every watt
you're burning up in the power supply, you're burning up more than four
watts in the computer.

Yes, it'll help -- but those CPUs and graphics cards have
tons-o-heatsink on them for a _reason_, and it ain't just to look good.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On 02/21/2011 07:51 PM, Bob La Londe wrote:


"Dennis" wrote in message
. au...

"Bob La Londe" wrote in message
...
How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.

I've used them quite a bit, cooling optics, built a small
environmental chamber etc. Without qualifying it with numbers I'd say
you would be wasting your time trying to use peltiers to cool air for
your pcs. Would using a very small thru wall compressor aircon unit be
possible? They are quite inexpensive.

My shop is 3000 square feet. About the only thing I can think of might
be to use an equipment cabinet and a small AC unit on it. Seems pretty
inefficient.

Inefficient how? If you can arrange all the confusers in there, it may
be just what you need. At least until the AC dies and you don't notice...

To beat the 'airflow' drum again -- how about an equipment cabinet and
just pipe in outside air?

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On Feb 21, 5:07*pm, Bob La Londe wrote:
How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. *My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. *I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.

I'd go water cooled. There are plans on the net if you don't want to
buy new.

Dennis wrote:

"Bob La Londe" wrote in message
...
How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.

I've used them quite a bit, cooling optics, built a small environmental
chamber etc. Without qualifying it with numbers I'd say you would be
wasting your time trying to use peltiers to cool air for your pcs. Would
using a very small thru wall compressor aircon unit be possible? They are
quite inexpensive.

I have a small window unit (good for, say, a master bedroom) that you can
have if you want to traipse on down to Whittier, CA and pick it up.

Cheers!
Rich

Dennis wrote:


"Bob La Londe" wrote in message
...
How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.

I've used them quite a bit, cooling optics, built a small environmental
chamber etc. Without qualifying it with numbers I'd say you would be
wasting your time trying to use peltiers to cool air for your pcs. Would
using a very small thru wall compressor aircon unit be possible? They are
quite inexpensive.

I mentioned one I have, but if I recall accurately, it was less than
$100.00. And now would be a good time to pick one up, before the cooling
season hits.

Cheers!
Rich

Bob La Londe wrote:
How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.
If it was me, Id go to the recycling center and get a s/hand fridge, and
put the pc's in that set to low or veryow.
Should work fine.
Ted

On Feb 21, 10:07*pm, Bob La Londe wrote:
How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. *My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. *I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.

Peltiers are maybe 25% efficient, so you'd be adding perhaps half a
kilowatt into the shop air. Could you swap in a fancy gamer CPU
heatsink? A Peltier on the cold side of one would do more good than
trying to cool the intake air.

I've used a Peltier to cool a diode laser, 8 Amps at 12V of input
power to remove ~15W of heat.

The little Summit dorm room refrigerator behind me is 15-3/4" wide
inside, (barely) enough to hold the old Dell Optiplex on my desk. It
draws 150-160W.

jsw

If the computer equipment is near a wall, then build a small
office, and AC to dump the heat from the office out doors?

Are you near cold water pipe? Might be able to make some
loops of soft copper, and water cool the PC.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Bob La Londe" wrote in message
...

My shop is 3000 square feet. About the only thing I can
think of might be
to use an equipment cabinet and a small AC unit on it.
Seems pretty
inefficient.

Bob La Londe wrote:
How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.

I seem to recall 50 degrees (F) is the max temperature difference
achievable.

Bill K7NOM

On Feb 21, 8:07*pm, Bob La Londe wrote:
How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. *My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. *I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.

The answer is to look up the dissipation of your CPUs on Intel's or
AMD's site, then look at the module. A middlin' fair CPU these days
will dissipate around 65 watts or so, some of the hot ones will go
twice that. Depending on the hot-side temp, a module goes 10-25%
efficient, which means you're going to be dumping a whole lot more
heat than you're going to be pulling out of the CPU. In my one live
trial with a Peltier fan sink, I managed to cook a set of memory DIMMs
during a hot spell. A larger fansink was the ultimate answer and kept
the CPU 10 degrees cooler than the module did.

They make portable AC units for spot cooling of computer gear, one of
those, or a window unit genned up to work like one, would probably be
the way to go.

Stan

"Bob La Londe" wrote in message
...
How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.

Darn. I had an apartment size fridge from my old office that would have
been perfect for 3-4 mini tower computers. Unfortunately when I built my
big shop and moved into it I put a big fridge in the shop and gave the
little one to my dad for his shop. Now how to talk him out of it. LOL. I
guess I'll just have to go drink all his beer and then explain that since he
doesn't have anything in it he really doesn't need it anymore.

"Bob La Londe" wrote in message
...
How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.

Darn. I had an apartment size fridge from my old office that would have
been perfect for 3-4 mini tower computers. Unfortunately when I built my
big shop and moved into it I put a big fridge in the shop and gave the
little one to my dad for his shop. Now how to talk him out of it. LOL. I
guess I'll just have to go drink all his beer and then explain that since he
doesn't have anything in it he really doesn't need it anymore.

On Feb 23, 12:10*pm, "Bob La Londe" wrote:
...
Darn. *I had an apartment size fridge from my old office that would have
been perfect for 3-4 mini tower computers.

They sell cheap near colleges in June.

jsw

On Feb 22, 8:00*am, Jim Wilkins wrote:
...
... Summit dorm room refrigerator ...... It
draws 150-160W.

jsw

I misread the KAWez. It draws 100W, 160VA. Based on 28 hours of use
the KAWez predicts $1.50 a month, cooling ~30 F degrees below room
temperature. YMMV.

jsw

On 02/23/2011 09:10 AM, Bob La Londe wrote:
"Bob La Londe" wrote in message
...
How much real cooling can you get with the cheap peltiers you find for
sale on Ebay. My shop gets pretty hot in the summer, but its just not
practical to keep my controller computers in the office. I was
thinking about making mini duct/shrouds to draw air over the cold side
of a peltier into the PC cases.

Darn. I had an apartment size fridge from my old office that would have
been perfect for 3-4 mini tower computers. Unfortunately when I built my
big shop and moved into it I put a big fridge in the shop and gave the
little one to my dad for his shop. Now how to talk him out of it. LOL. I
guess I'll just have to go drink all his beer and then explain that
since he doesn't have anything in it he really doesn't need it anymore.

You can't find a cheap fridge in Craigslist?

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html