Cheap Peltier air conditioner?

[Gregory Toomey]

Domestic fan heaters are cheap but air conditioners are a lot more
expensive.

There seem to be lots of cheap Peltier cooling devices coming to the market.
I was wondering whether a fan could be combined with a Peltier device to
make a cheap air conditioner.

http://www.ferrotec-america.com/pel.htm
http://www.abc.net.au/science/k2/homework/s95611.htm

gtoomey

 

[Trevor Wilson]

"Gregory Toomey" <NOSPAM@bigpond.com> wrote in message
news:bjbab4$glsnl$1@ID-202028.news.uni-berlin.de...

Domestic fan heaters are cheap but air conditioners are a lot more
expensive.

There seem to be lots of cheap Peltier cooling devices coming to the
market.
I was wondering whether a fan could be combined with a Peltier device to
make a cheap air conditioner.

http://www.ferrotec-america.com/pel.htm
http://www.abc.net.au/science/k2/homework/s95611.htm

**Points:
1) It would not be cheap. A small air con delivers around 1,500 watts of
cold air with less than 1,000 Watts of input power. A typical Peltier device
delivers less than 30 Watts of cold air, with more than 30 Watts of input
power. You'll need *a lot* of Peltier devices, *a lot* of heat sinks and *a
lot* of power.
2) Peltier device generate their heat around away from the cold bit. It
will require heroic methods to shift the heat away.


--
Trevor Wilson
www.rageaudio.com.au

 

[Arpit]

THink about it, an average 2 hp air conditioner pumps 1400 watts. say
your pelters pump 80 watts each, you need 18 to match that. At 20
dollars each thats only about 400 dollars. BUT each one will draw
about 7 amps at 12 volts. So your elelctricity charges will be very
large. YOu can power them by 9 good computer power supplies, if you
find a trash bin full of them, your ok, but otherwise expect to pay at
least 30 dollars new. Plus you'll need to give them a resistor to load
the 5 volt rail. THen theres the problem of getting rid of 1400 watts
YOud need a huge ugly black heatsink arrangement, which would be
expensive, or a more elegant solution would be to use lots of computer
amd or p4 cpu coolers. naturally these would be poking out your wall.
And would be really noisy and whiny. Youd need pretty much the same
thing on your side too, to cool the room. FInally comes switching.
PEltiers dont like to be switched at low frequencies so youll need to
build something to drive themm at a few kilohertz. Welll, rather, 9
things, each capable of 18 amps. SO the minimum price list

Peltiers: 360 dollars
Tools to cut holes in your wall: 300 dollars
CpU coolers: 540 dollars
Total: 1200 dollars

More realistic cost list
Pelters: 630 dollars
Power supplies: 450 dollars
Resistors: 5 dollars
Coolers: 1080 dollars
Driver circuitry: 270 dollars

Total: 2435 dollars

On Sat, 6 Sep 2003 10:39:06 +1000, "Gregory Toomey"
<NOSPAM@bigpond.com> wrote:

Domestic fan heaters are cheap but air conditioners are a lot more
expensive.

There seem to be lots of cheap Peltier cooling devices coming to the market.
I was wondering whether a fan could be combined with a Peltier device to
make a cheap air conditioner.

http://www.ferrotec-america.com/pel.htm
http://www.abc.net.au/science/k2/homework/s95611.htm

gtoomey

 

[Gregory Toomey]

"Trevor Wilson" <trevor@rageaudio.com.au> wrote in message
news:3f5933b9$1@news.comindico.com.au...

**Points:
1) It would not be cheap. A small air con delivers around 1,500 watts of
cold air with less than 1,000 Watts of input power. A typical Peltier
device
delivers less than 30 Watts of cold air, with more than 30 Watts of input
power. You'll need *a lot* of Peltier devices, *a lot* of heat sinks and
*a
lot* of power.

I've only seen these devices in the past year, though the effect was
discovered over a century ago. Maybe more research is needed, just like
superconductors/fuel cells/solar panels. Consumers would buy a 500 watt
device with a simple fan that sits in a window, provided it costs less to
manufacture than an evaporative air conditioner.

2) Peltier device generate their heat around away from the cold bit. It
will require heroic methods to shift the heat away.

Just mount it in a window with the hot end outside.

gtoomey

 

[Uncle Al]

Gregory Toomey wrote:

Domestic fan heaters are cheap but air conditioners are a lot more
expensive.

There seem to be lots of cheap Peltier cooling devices coming to the market.
I was wondering whether a fan could be combined with a Peltier device to
make a cheap air conditioner.

http://www.ferrotec-america.com/pel.htm
http://www.abc.net.au/science/k2/homework/s95611.htm

Peltier coolers have low efficiency and are unsuited to moving large
amounts of heat. They are good for quiet spot cooling and maintaining
the temp of a well-insulated volume. One ton of air conditioning
might barely do a nice home for 24 hours in the summer - the energy of
melting one ton of ice at 80 cal/gm or 80 million calories. One
cannot imagine a Peltier cooler that large - or its electric bill.

Peltier CPU coolers are not even suitable for (admittedly crappy)
Intel Pentium IV's and their 30-50 watt heat outputs. You would need
a 100-250 watt cooler. What cools the cooler's hot side?

A Ranque-Hilsch vortex tube won't do it either - too inefficient, too
noisy. A freon refrigerator is engineering and thermodynamic heaven
on Earth. Safe and cheap, too. That is why Luddite Enviro-whiners
hate it so. They violate the Enviro-whiner holy trinity: Expensive,
shoddy, deadly. ("Shoddy" was the first recycled wool back in
Industrial Revolution days. How good do you think it was?)

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
"Quis custodiet ipsos custodes?" The Net!

 

[Uncle Al]

Gregory Toomey wrote:

"Trevor Wilson" <trevor@rageaudio.com.au> wrote in message
news:3f5933b9$1@news.comindico.com.au...

**Points:
1) It would not be cheap. A small air con delivers around 1,500 watts of
cold air with less than 1,000 Watts of input power. A typical Peltier
device
delivers less than 30 Watts of cold air, with more than 30 Watts of input
power. You'll need *a lot* of Peltier devices, *a lot* of heat sinks and
*a
lot* of power.

I've only seen these devices in the past year, though the effect was
discovered over a century ago. Maybe more research is needed, just like
superconductors/fuel cells/solar panels. Consumers would buy a 500 watt
device with a simple fan that sits in a window, provided it costs less to
manufacture than an evaporative air conditioner.

2) Peltier device generate their heat around away from the cold bit. It
will require heroic methods to shift the heat away.

Just mount it in a window with the hot end outside.

You do it. Watch the thing melt before your eyes. The cold plate and
hot plate of a Peltier cooler are separated by about 3 mm - and for
good reason. Do you know how a Peltier cooler works?

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
"Quis custodiet ipsos custodes?" The Net!

 

[Rod Speed]

Gregory Toomey <NOSPAM@bigpond.com> wrote in message
news:bjbd65$gotds$1@ID-202028.news.uni-berlin.de...

Trevor Wilson <trevor@rageaudio.com.au> wrote

Points:
1) It would not be cheap.

Not cheap to run, anyway.

A small air con delivers around 1,500 watts of
cold air with less than 1,000 Watts of input power.
A typical Peltier device delivers less than 30 Watts
of cold air, with more than 30 Watts of input power.
You'll need *a lot* of Peltier devices, *a lot* of heat
sinks and *a lot* of power.

Correct.

I've only seen these devices in the past year, though
the effect was discovered over a century ago.

They've been around for years now,
not uncommon with camping eskys etc.

Maybe more research is needed, just like
superconductors/fuel cells/solar panels.

'more research' wont help, the current ones do close
to whats theoretically possible and thats nothing like
the running cost you get with a true airconditioner.

Basic physics that no 'research' can change.

Consumers would buy a 500 watt device with a simple
fan that sits in a window, provided it costs less to
manufacture than an evaporative air conditioner.

What matters is the running cost, not the purchase price.

2) Peltier device generate their heat around away from the
cold bit. It will require heroic methods to shift the heat away.

Just mount it in a window with the hot end outside.

Pity about the electrical power required to provide useful cooling.

 

[MC]

Domestic fan heaters are cheap but air conditioners are a lot more
expensive.

There seem to be lots of cheap Peltier cooling devices coming to the market.
I was wondering whether a fan could be combined with a Peltier device to
make a cheap air conditioner.

Some problems.
(1)
Peltiers are not very efficient heat transferers. They move
somewhere around 0.5 to 0.75 of whatever their supplied power is.
A typical gas-based reverse-cycle unit can move 2 to 4 times
the supplied power.

(2)
The cold-surface is rather close to the heating surface, which
makes it 'challenging' to keep the cool-air seperated from the
'hot air'.

 

[Gregory Toomey]

"Uncle Al" <UncleAl0@hate.spam.net> wrote in message
news:3F593CD6.E428D893@hate.spam.net...

Gregory Toomey wrote:


You do it. Watch the thing melt before your eyes. The cold plate and
hot plate of a Peltier cooler are separated by about 3 mm - and for
good reason. Do you know how a Peltier cooler works?

Yes, but I'm no expert at thermodynamics. There are a number of small
Peltier refrigerators (mainly for vehicle use) so I thought an air
conditioner would be possible.

gtoomey

 

[Gregory Toomey]

Dissipating the heat should be possible.

For comparision, modern CPUs put out >60 Watts. With a heatsink, the CPU
fan only consumes about 1 Watt. Some CPUs are even passively cooled.


gtoomey

 

[Arpit]

2) Peltier device generate their heat around away from the
cold bit. It will require heroic methods to shift the heat away.

Just mount it in a window with the hot end outside.

Pity about the electrical power required to provide useful cooling.

Yep, Even a portable air conditioner beats them.

 

[Russ]

"Gregory Toomey" <NOSPAM@bigpond.com> wrote in message
news:bjbd65$gotds$1@ID-202028.news.uni-berlin.de...

"Trevor Wilson" <trevor@rageaudio.com.au> wrote in message
news:3f5933b9$1@news.comindico.com.au...

**Points:
1) It would not be cheap. A small air con delivers around 1,500 watts of
cold air with less than 1,000 Watts of input power. A typical Peltier
device
delivers less than 30 Watts of cold air, with more than 30 Watts of
input
power. You'll need *a lot* of Peltier devices, *a lot* of heat sinks and
*a
lot* of power.

I've only seen these devices in the past year, though the effect was
discovered over a century ago. Maybe more research is needed, just like
superconductors/fuel cells/solar panels. Consumers would buy a 500 watt
device with a simple fan that sits in a window, provided it costs less to
manufacture than an evaporative air conditioner.

I think what you are missing is the reason behind using both heat pumps and
evaporative air conditions - they both exploit physical principles for
efficient cooling - that is, they remove more heat than they require to run.

Peltiers are inherently inefficient, and are thus a poor choice, except for
specific applications where their simplicity and size make them appropriate,
such as esky heater/coolers.

Russ.

 

[Paul R. Mays]

"Arpit" <DONTSPAMMEF00Lneko4@dodo.com.au> wrote in message
news:25cilvg78djp5jalogvuaamd3q9qimmb1t@4ax.com...

THink about it, an average 2 hp air conditioner pumps 1400 watts. say
your pelters pump 80 watts each, you need 18 to match that. At 20
dollars each thats only about 400 dollars. BUT each one will draw
about 7 amps at 12 volts.

Just a couple of points....
a single 2k power supply would supply more than enough
current for 18 pelt's which at 120vac only needs 10 amps
which is less than most AC units of same cooling value..

Then use a dual water cooling and heating system with a
fairly small pump (2) add a couple of fans to move
air across radiators and you have a self contained
window unit that may cost a bit more up front ( not much)
and would be a bit less per month to run... but would
require no leakage coolants in the system.. just water
and antifreeze... and be smaller to...

I could design and build a prototype for maybe
2 grand or so but under production the cost
would be less than half ..maybe down to 500 bucks
for a 8kbtu unit...

So your elelctricity charges will be very
large. YOu can power them by 9 good computer power supplies, if you
find a trash bin full of them, your ok, but otherwise expect to pay at
least 30 dollars new. Plus you'll need to give them a resistor to load
the 5 volt rail. THen theres the problem of getting rid of 1400 watts
YOud need a huge ugly black heatsink arrangement, which would be
expensive, or a more elegant solution would be to use lots of computer
amd or p4 cpu coolers. naturally these would be poking out your wall.
And would be really noisy and whiny. Youd need pretty much the same
thing on your side too, to cool the room. FInally comes switching.
PEltiers dont like to be switched at low frequencies so youll need to
build something to drive themm at a few kilohertz. Welll, rather, 9
things, each capable of 18 amps. SO the minimum price list

Peltiers: 360 dollars
Tools to cut holes in your wall: 300 dollars
CpU coolers: 540 dollars
Total: 1200 dollars

More realistic cost list
Pelters: 630 dollars
Power supplies: 450 dollars
Resistors: 5 dollars
Coolers: 1080 dollars
Driver circuitry: 270 dollars

Total: 2435 dollars

On Sat, 6 Sep 2003 10:39:06 +1000, "Gregory Toomey"
NOSPAM@bigpond.com> wrote:

Domestic fan heaters are cheap but air conditioners are a lot more
expensive.

There seem to be lots of cheap Peltier cooling devices coming to the
market.
I was wondering whether a fan could be combined with a Peltier device to
make a cheap air conditioner.

http://www.ferrotec-america.com/pel.htm
http://www.abc.net.au/science/k2/homework/s95611.htm

gtoomey

 

[Gregory Toomey]

"Paul R. Mays" <simatar1@hotmail.Com> wrote in message
news:AoednVDTnb3MG8SiRVn-jg@giganews.com...

"Arpit" <DONTSPAMMEF00Lneko4@dodo.com.au> wrote in message
news:25cilvg78djp5jalogvuaamd3q9qimmb1t@4ax.com...
THink about it, an average 2 hp air conditioner pumps 1400 watts. say
your pelters pump 80 watts each, you need 18 to match that. At 20
dollars each thats only about 400 dollars. BUT each one will draw
about 7 amps at 12 volts.

Just a couple of points....
a single 2k power supply would supply more than enough
current for 18 pelt's which at 120vac only needs 10 amps
which is less than most AC units of same cooling value..

Then use a dual water cooling and heating system with a
fairly small pump (2) add a couple of fans to move
air across radiators and you have a self contained
window unit that may cost a bit more up front ( not much)
and would be a bit less per month to run... but would
require no leakage coolants in the system.. just water
and antifreeze... and be smaller to...

I could design and build a prototype for maybe
2 grand or so but under production the cost
would be less than half ..maybe down to 500 bucks
for a 8kbtu unit...

I was thinking along the same lines. There is probably a market for a
cheaper (and proably quieter) window unit. If you can just get away with
fans & heatsinks I think there would be a big market.

gtoomey

 

[Rod Speed]

"Gregory Toomey" <NOSPAM@bigpond.com> wrote in message news:bjbfmr$h34vj$1@ID-202028.news.uni-berlin.de...

"Uncle Al" <UncleAl0@hate.spam.net> wrote in message
news:3F593CD6.E428D893@hate.spam.net...
Gregory Toomey wrote:


You do it. Watch the thing melt before your eyes. The cold plate and
hot plate of a Peltier cooler are separated by about 3 mm - and for
good reason. Do you know how a Peltier cooler works?

Yes, but I'm no expert at thermodynamics.

Or even basic physics either.

There are a number of small Peltier refrigerators (mainly for vehicle use)

Correct.

so I thought an air conditioner would be possible.

The difference is that with a small fridge, you only have to pump
out what leaks in thru the insulation. Doing a whole room is completely
different and you basically have to pump a lot more heat, and peltier is
hopeless for that. If you want cheap, evaporative is the way to go unless
its very humid. Otherwise there is no substitute for real airconditioning.

You should have noticed that while peltier is used for
fridges in vehicles, it aint used to cool the vehicle itself.
They use a real airconditioner for a reason.

 

[Rod Speed]

Paul R. Mays <simatar1@hotmail.Com> wrote in message
news:AoednVDTnb3MG8SiRVn-jg@giganews.com...

Arpit <DONTSPAMMEF00Lneko4@dodo.com.au> wrote

THink about it, an average 2 hp air conditioner pumps 1400
watts. say your pelters pump 80 watts each, you need 18 to
match that. At 20 dollars each thats only about 400 dollars.
BUT each one will draw about 7 amps at 12 volts.

Just a couple of points....
a single 2k power supply would supply more than enough
current for 18 pelt's which at 120vac only needs 10 amps
which is less than most AC units of same cooling value..

Then use a dual water cooling and heating system
with a fairly small pump (2) add a couple of fans to
move air across radiators and you have a self contained
window unit that may cost a bit more up front ( not much)
and would be a bit less per month to run... but would
require no leakage coolants in the system.. just water
and antifreeze... and be smaller to...

Pity the running cost is much worse than a real airconditioner.

And if water is available, you might as well just cut to
the chase and have an evaporative air cooler instead.

Which just happens to be what is done.

I could design and build a prototype for maybe
2 grand or so but under production the cost
would be less than half ..maybe down to 500 bucks
for a 8kbtu unit...

So your elelctricity charges will be very
large. YOu can power them by 9 good computer power supplies, if you
find a trash bin full of them, your ok, but otherwise expect to pay at
least 30 dollars new. Plus you'll need to give them a resistor to load
the 5 volt rail. THen theres the problem of getting rid of 1400 watts
YOud need a huge ugly black heatsink arrangement, which would be
expensive, or a more elegant solution would be to use lots of computer
amd or p4 cpu coolers. naturally these would be poking out your wall.
And would be really noisy and whiny. Youd need pretty much the same
thing on your side too, to cool the room. FInally comes switching.
PEltiers dont like to be switched at low frequencies so youll need to
build something to drive themm at a few kilohertz. Welll, rather, 9
things, each capable of 18 amps. SO the minimum price list

Peltiers: 360 dollars
Tools to cut holes in your wall: 300 dollars
CpU coolers: 540 dollars
Total: 1200 dollars

More realistic cost list
Pelters: 630 dollars
Power supplies: 450 dollars
Resistors: 5 dollars
Coolers: 1080 dollars
Driver circuitry: 270 dollars

Total: 2435 dollars

On Sat, 6 Sep 2003 10:39:06 +1000, "Gregory Toomey"
NOSPAM@bigpond.com> wrote:

Domestic fan heaters are cheap but air conditioners are a lot more
expensive.

There seem to be lots of cheap Peltier cooling devices coming to the
market.
I was wondering whether a fan could be combined with a Peltier device to
make a cheap air conditioner.

http://www.ferrotec-america.com/pel.htm
http://www.abc.net.au/science/k2/homework/s95611.htm

gtoomey

 

[Rod Speed]

"Gregory Toomey" <NOSPAM@bigpond.com> wrote in message news:bjccka$gumf8$1@ID-202028.news.uni-berlin.de...

"Paul R. Mays" <simatar1@hotmail.Com> wrote in message
news:AoednVDTnb3MG8SiRVn-jg@giganews.com...

"Arpit" <DONTSPAMMEF00Lneko4@dodo.com.au> wrote in message
news:25cilvg78djp5jalogvuaamd3q9qimmb1t@4ax.com...
THink about it, an average 2 hp air conditioner pumps 1400 watts. say
your pelters pump 80 watts each, you need 18 to match that. At 20
dollars each thats only about 400 dollars. BUT each one will draw
about 7 amps at 12 volts.

Just a couple of points....
a single 2k power supply would supply more than enough
current for 18 pelt's which at 120vac only needs 10 amps
which is less than most AC units of same cooling value..

Then use a dual water cooling and heating system with a
fairly small pump (2) add a couple of fans to move
air across radiators and you have a self contained
window unit that may cost a bit more up front ( not much)
and would be a bit less per month to run... but would
require no leakage coolants in the system.. just water
and antifreeze... and be smaller to...

I could design and build a prototype for maybe
2 grand or so but under production the cost
would be less than half ..maybe down to 500 bucks
for a 8kbtu unit...

I was thinking along the same lines. There is probably a
market for a cheaper (and proably quieter) window unit.

Nope, because of atrocious running costs.

If you want quieter, you just use a split system.

If you can just get away with fans & heatsinks
I think there would be a big market.

You're wrong, because of the running cost.

 

[DarkMatter]

On Sun, 7 Sep 2003 04:35:01 +1000, "Rod Speed" <rod_speed@yahoo.com>
Gave us:

"Gregory Toomey" <NOSPAM@bigpond.com> wrote in message news:bjccka$gumf8$1@ID-202028.news.uni-berlin.de...
"Paul R. Mays" <simatar1@hotmail.Com> wrote in message
news:AoednVDTnb3MG8SiRVn-jg@giganews.com...

I was thinking along the same lines. There is probably a
market for a cheaper (and proably quieter) window unit.

Nope, because of atrocious running costs.

If you want quieter, you just use a split system.

If you can just get away with fans & heatsinks
I think there would be a big market.

You're wrong, because of the running cost.


It would be nice if the smart folk, like you would extend those

brains to being smart enough to trim the irrelevant parts of your
reply away. DUH!

You put down one idiot's remarks, replying to one sentence, yet your
stupid ass STILL quoted the entire tripe post. You need to get more
clues than those you have chosen to embrace, boy.

 

[Trevor Wilson]

"DarkMatter" <DarkMatter@thebarattheendoftheuniverse.org> wrote in message
news:l5gklvclhmln0ga0uu68v66pc38gfag2pt@4ax.com...

On Sun, 7 Sep 2003 04:35:01 +1000, "Rod Speed" <rod_speed@yahoo.com
Gave us:


"Gregory Toomey" <NOSPAM@bigpond.com> wrote in message
news:bjccka$gumf8$1@ID-202028.news.uni-berlin.de...
"Paul R. Mays" <simatar1@hotmail.Com> wrote in message
news:AoednVDTnb3MG8SiRVn-jg@giganews.com...

I was thinking along the same lines. There is probably a
market for a cheaper (and proably quieter) window unit.

Nope, because of atrocious running costs.

If you want quieter, you just use a split system.

If you can just get away with fans & heatsinks
I think there would be a big market.

You're wrong, because of the running cost.


It would be nice if the smart folk, like you would extend those
brains to being smart enough to trim the irrelevant parts of your
reply away. DUH!

You put down one idiot's remarks, replying to one sentence, yet your
stupid ass STILL quoted the entire tripe post. You need to get more
clues than those you have chosen to embrace, boy.

**I don't think so. It has been explained to Mr Toomey the reasons why
Peltier devices are completely unsuited to air conditioning, yet he keeps
asking the same questions, in different ways. It can be very frustrating.


--
Trevor Wilson
www.rageaudio.com.au

 

[Gregory Toomey]

"Trevor Wilson" <trevor@rageaudio.com.au> wrote in message
news:3f5a67f4$1@news.comindico.com.au...

**I don't think so. It has been explained to Mr Toomey the reasons why
Peltier devices are completely unsuited to air conditioning, yet he keeps
asking the same questions, in different ways. It can be very frustrating.

With somebody offering to make a prototype ...

gtoomey