Instructables

Mini Peltier Air Conditioner (Plans)

Picture of Mini Peltier Air Conditioner (Plans)
This Instructable will show you how to make a environmental friendly portable air conditioner. This machine uses a Peltier Module as a cooling  mechanism and some cooling fans for blowing air.
 
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Step 1: Here is a Picture How It Works

Picture of Here is a Picture How It Works
This is just like the everyday air conditioner that we use. The only thing unique about this that the cooling unit has no moving parts. The only moving parts here are the PC fans.

Step 2: Needed Parts, Tools and Materials

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This page shows you the things that you need that you need to buid this machine.

Step 3: Ilustration

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Step 4: Notes Before Starting

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Step 5: Electrical Wiring

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Step 6: Attaching The Heat Sinks

Picture of Attaching The Heat Sinks
Put epoxy on both sides of the peltier module and connect the heat sinks together.
Note: Copper paste would be better.

Step 7: Attaching The Fans

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Put epoxy on the heat sinks and connect the two PC fans to the heat sinks.

Step 8: Attaching The Wood

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Attach the wood with epoxy.

Step 9: Attaching The Wood and The Metal Net

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Use Epoxy

Step 10: Attaching The Wood

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Use epoxy.

Step 11:

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Step 12: What It Looks Like

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Step 13: How To Use It

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Use the tube for better ventilation.
a good improvement would be to water cool the hotside of the peliter and to put the radiator outside. peltiers use alot of electricity, they use 100w to move 100w of heat roughly.
rmckay511 days ago
Hi,
I'm trying to make something very similar to this design, but I'm having some wiring problems. Peltiers are really hard to find where I live and the only one I could get my hands on has no markings and no instructions - the only thing the seller knew about it is that it's 12v. I have a 12v 3.3A DC adaptor and when I wire it all up in parallel the LED on the adaptor blinks, the peltier works, but the fans just twitch like they're trying to start but can't. When I wire it in series it all works fine, but the peltier doesn't get very hot/cold at all. Is my DC adaptor amperage too low or too high? Any suggestions would help!
plucas11 month ago

a few notes, a radiator with water on hot side would be great addition. as your design is you are blowing both hot and cold air into a room (I admit they are blowing in different directions though) with a water setup on the back you could take the heat outside and let the air blow on it to cool it down. the addition of several items like a pump will be required.

also using 2 or 3 peltiers piggy backed will be better than 1

and last but not least is you may encounter an icing issue.

zeeshanudsd3 months ago
hi
i want to know if i want to use it as heater what will i do b/c whenever it is used for cooling heating side is connected to the heating side so if we reverse the polarity than cooling side become hotter so is there heat sink is required for heating side?
naufanmaker3 months ago
attach it on the computer... 28c idle 60c full load!
ASCAS (author)  naufanmaker3 months ago
Now that's a great idea!
astral_mage7 months ago
or use thermal tape double sided, wich would be better. then u could take them apart. if u screwed up on some thing.
ampeyro3 years ago
how expensive is one of this peltier coolers?
http://tegpower.com/
go there and check them out
The prices on these can be from a few dollars to a few hundred. You have to choose your sources well.

Personally, I find that eBay has the best prices. I just bought two modules and each cost about $4, free shipping.

http://cgi.ebay.ca/Cooler-Peltiers-TEC1-12706-Thermoelectric-Fine-12V-60W-/280705809456?pt=LH_DefaultDomain_0&hash=item415b5ebc30
astral_mage7 months ago
http://tegpower.com/ there they have them from 25$ units up to 2000.00$
astral_mage7 months ago
well one good place is to check out this link http://tegpower.com
go there is yr looking 4 thermal electric generators. yr looking at 85% heat conversion or soo

cutshopguy8 months ago
What awesome presentation. A pleasure to read. Well done.
pavelow1 year ago
If you follow the instructions you will fry your peltier. I just fried mine. A 7AH cell in good working order will overpower it within about 30 seconds. Melted the solder right out of the side before I knew what happened. (And yes I had a substantial heat sync). You need something to limit the current if you are going to use a battery.
depends on the voltage you supply the peltier with- but I would agree generally it would be better to limit the current somehow. But you can measure the resistance of the peltier when it's at room temperature, and calculate the expected amperage at whatever voltage battery you use (V=IR).
robcull Kinnishian11 months ago
A peltier doesn't work that way. It's like a diode- it's made of semiconducting materials, therefore different rules apply. First, here's a quick comparison of voltage (or "potential difference") versus current for resistors, diodes and filament lamps: 

http://www.bbc.co.uk/schools/gcsebitesize/science/add_edexcel/controlling_current/resistancerev2.shtml 

In a graph of voltage vs current, the derivative (i.e. the slope) of the line at any point is the resistance. When the graph is steep, the resistance is high. This comes from V=IR (in this case, it makes more sense as V / I = R). Now, lets take a look at a more detailed generic voltage (V_D) vs current (I_D) graph for a diode: 

http://tinyurl.com/diode-graph-jpg

As you likely already know, when you connect a peltier to a power source, one side gets hot and one gets cold. If you apply a negative voltage (i.e. switch positive and negative), the sides essentially switch. You can see this in the graph- notice what the current does when you go further left, giving a negative voltage. These two regions are labeled in the graph as the Forward and Reverse regions. 

As you can see from this graph, a peltier's electrical resistance varies exponentially as the voltage changes. That's why you can't approach the problem this way (unless you have some expensive lab equipment like a curve tracer that could model your peltier for you). 

So how do you avoid frying your peltier? You don't limit the current (directly, at least). Instead, you limit the voltage by putting a resistor between the battery and the peltier. You need to use the correct resistor- you can either do the math or find a calculator online to determine what resistor you need in order to make the voltage whatever your peltier is rated for. You want to get as close to the right voltage without going past it... look at the graph again- the correct voltage for your peltier is labeled as the "knee voltage." What happens if you are just below the target voltage? Your peltier will simply not get very hot/cold. But what happens if you are just above the target voltage? Your peltier will melt your face off. 
Kinnishian robcull11 months ago
Robcull, I've reread what you said and you're not wrong. But I don't think you're really right, either.

Peltier modules will, without heatsinking, be melt away by my methodology. A, say, 5A peltier module will quickly melt with 5A, but it's rated as such that if it's well heatsunk, it can tolerate 5A.

I know at the place I worked last semester we simply had a 48V DC, applied to massive peltier modules. The current was limited by the resistance of the modules. There was some talk about in the future matching it more adjustable by chopping the DC voltage.

Long story short, I'm not a fan of using a ballast resistor, because it wastes energy. A peltier module is a semiconducting material, but it is not quite like a diode. It does drop resistance a little as it heats up, because it its easier to jump the band gap, but it can still be treated as a relatively constant resistance unit, at least in my experience.

I am very very open to being corrected, and admit that I only have a bit of experience with peltier modules. Am I missing something huge? Please correct me!! But I don't think your explanation was sufficient.
Kinnishian robcull11 months ago
I'm sorry, I should have said that you need to measure it's AC resistance with a special meter. I'm not sure why I said it so simply before. I'm going to read your comment now and double check what you're talking about.
This is probably gonna sound stupid but would it be possible to use 4 AA Batteries to power this thing?

I wanna build a pure portable AC to take with me to beat the heat on those long train/bus rides, I plan to use rechargeable AA batteries of cours.
Here's the problem- see how one side of the peltier throws off cool air while the other throws off hot air? The idea behind this instructable is to vent the hot air outside or something, while venting the cooled room (neutral) air back into the room.
Would work . They give of alot of heat. though . and use abit of power. your best of using a fan mist spray thing .
ASCAS (author)  ultimatenoob2 years ago
probably it wont work since peltier modules consumes a lot of electricity
not even enough to last 30mins to 1hr?
ASCAS (author)  ultimatenoob2 years ago
yes it could last for 1 hr but you need to choose a low wattage peltier module.
I see, Any idea on how to find one? I had this my eyes on this one

http://www.ebay.com.au/itm/New-2-pcs-TEC1-12708-Thermoelectric-Cooler-Peltier-12V-/260779788097?pt=LH_DefaultDomain_0&hash=item3cb7afc741#ht_2578wt_952
But from the title its a 12volt peltier?

Also i was planning to put a heat sink with a fan on the hot side, For the cold side, can i just pop this 'Heat Sink Fan' on the cold side to make it blow cold air?

http://www.ebay.com.au/itm/New-Cooling-Fan-Heatsink-Cooler-CPU-VGA-Video-Card-/140576673236?pt=AU_Components&hash=item20bb05cdd4#ht_3165wt_905

or maybe this one?

http://www.ebay.com.au/itm/North-South-Bridge-shipset-40mm-cooling-fan-Heatsink-2p-/140635732694?pt=LH_DefaultDomain_2&hash=item20be8afad6#ht_2544wt_975

Thanks for the help
animes251 year ago
I am just fear one thing, hope you can help me, it is safe to use epoxy when is heated at those temperatures? it will dont expel poisonous gases or something?

sorry for my bad english, is not my first language
I am a professional designer and user of TEC/Peltier modules

This instructable, whilst very enthusiastic, and very nicely illustrated won't work as advertised. Moving HEAT is not the same as creating a temperature difference.  A Peltier cell will only create a maximum delta T of about 50 C, and pump NO heat, or it will pump its "rated power" at ZERO delta T. In truth, getting 25 C at half power, in normal ambients is doing well.

Real airconditioners can cool more than their electrical input, Peltier cells can't technically, the Coefficient of performance of a real aircon is >> 100%, for a TEC< 100%.
Doesn't a device with COP > 100% break the laws of thermodynamics? Seems like if that were true, you'd be able to harvest the difference in output to power the system, which... you obviously cannot.
Its easier to point you at Wikipedia than to explain here, but suffice to say, no, thermodynamics isn't violated. ........
TeslaBoy1 year ago
What about CPU thermal transfer paste from Radio Shack and some Super Glue on the edge of the Peltier junction?
dkiehl2 years ago
Wouldn't you route the hot air from the 1st unit into the air intake of the 2nd unit?
I read that the hotter the incoming air is the coulder the output air is.
No way thats crazy talk !!

they cool 20 bellow ambient . if the neutral air is 60 degrees it will cool to 40deg c
The more heat energy it can give of the colder it can get. If you had a massive heat sink and water cooled it would get colder .
junits153 years ago
something like this is usually very hard to get working, because there are some many things that can go wrong. fans heatsinks power supplies. I have a peltier and a watercooler for it, but i still cant find a 12VDC 14 amp power supply. :(
Rottom junits152 years ago
try amazon, ebay, ask.com,google.com
junits15 Rottom2 years ago
I already got a power supply a loooooong time ago, its an xbox 360 psu, those things are awesome!
oh oh oh u could make the 14 amp supply from an old microwave transformer just chisel away the smaller 2000 volt windings and wrap it with some 10 gauge wire until it puts out 14 amps at 12 volts but i think that wire thickness determines the amount of amps idk im not sure and u could just buy some beefy diodes to make the voltage dc and a capicitor but on the other hand is it possible to force too power into a peltier or will it just use what it needs?
ive actually already got a power supply :) my xbox 360 just dies so Im taking the power brick from that is has a 16 amp 12v rail and a 1 amp 5 volt rail
ur lucky. im gonna try my idea and if ur peltier takes 14 amps wont the 16 amp power supply fry the peltier?
no 16 amps is the max current that can be drawn from the psu, 14 amps os the amount the TEC will draw, so it wont fry. btw you can get 360 PSUs on ebay for $15-$20
Ok thanks now i don't have to worry and that's a good idea i think i will get 1 of those or i could make a power supply (its gonna be a giant wallwart) and i could spend the money on a giant peltier idk.
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