Homemade Peltier Cooler W/ Temperature Control DIY Reusing Old PC Computer Parts





Introduction: Homemade Peltier Cooler W/ Temperature Control DIY Reusing Old PC Computer Parts

About: I really like to experiment and build stuff. I also like to share the things I learned from these various projects. I hope you will find this information useful and that it will inspire you to build great th...

There are some great instructables showing you how to build a homemade Peltier cooler and I hope you will enjoy my version of it. Let's see how I recycled my old PC computer into a thermoelectric Peltier mini fridge with a W1209 temperature controller.

I had an old cpu that I was not using and wanted to give it a second life. I could not think of a better DIY electronics project than to reuse some of its parts to build a homemade mini fridge. I used the ATX power supply and heatsinks from the computer as well as a Styrofoam shipping box I had. The fridge uses a thermoelectric Peltier module TEC1-12706 for cooling. Basically, you apply DC current to this small ceramic square to cool down one side whereas the other gets hot. The heatsinks are used to dissipate heat or cold on either side with the fans. The W1209 digital thermostat allows you to set the desired temperature. You can expect a 10-15 celcius temperature difference between the cooler and ambient temperature. In Fahrenheit, it went from 70 to 50 degrees. This cooler is obviously not as efficient as a classic compressor refrigerator but it’s a cool electronic gadget that is easy to build! Check my ATX breakout board Instructables or my youtube video for more information about the lab bench power supply used in this project and how to do the conversion of your ATX computer power supply. I hope you will find this tutorial useful.

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Please have a look at the next step to see every items you need to build your homemade Peltier mini fridge.

You can also learn more about the seebeck effect and how these Peltier units work on wikipedia.


Warning and disclaimer: ATX PSU can deliver enough current to cause serious injuries or death. I am not responsible for any accidents or damages.

Step 1: Everything You Need for This DIY Project

***Homemade Peltier Cooler Refrigerator (about 8$):

-Peltier module TEC1 12706 (eBay.com, CA, UK, DE, FR) (Aliexpress) (Amazon)

-Temperature controller W1209 digital thermostat (eBay.com, CA, UK, DE, FR) (Aliexpress) (Amazon)

-Thermal conductive silicone pad (eBay.com, CA, UK, DE, FR) (Aliexpress)

-8cm Computer fan 12V 2 pins (eBay.com, CA, UK, DE, FR) (Aliexpress)

-4cm Computer fan 24V 2 pins (eBay.com, CA, UK, DE, FR) (Aliexpress)

-Styrofoam shipping box (or any type of cooler you have on hand)

-Small and large heatsinks from an old PC computer or any heatsinks you may have

-Electrical wires (I'm using AWG14 wires and Dupont cables)

-Hot glue gun

***Homemade ATX lab bench power supply (check my other instructables for more informations about the computer power supply conversion- about 8$)

-ATX breakout board (eBay.com, CA, UK, DE, FR) (Aliexpress) (Amazon)

-ATX power supply (I took mine out of an old cpu. They cost about 30$ US on eBay)

Step 2: Cut a Hole in the Lid of the Styrofoam Cooler

I’m using a Styrofoam cooler to build the Peltier mini-fridge (8 x 6.5 x 8 inches, can hold up to 8 cans).

You should use the smaller heatsink for the inner side of the cooler. Therefore, the hole should be the same size as this heatsink.

Step 3: Assemble the Peltier Module With the Heatsinks on Each Side

Before assembling the module, you should test the Peltier for a few seconds with a 1.5V battery to determine which side gets hot and place the larger heatsink on it.

I used a conductive thermal silicone pad to make the Peltier sandwich, but you can use thermal paste if you prefer. You can now place the smaller heatsink on the cold side and introduce it into the lid of the cooler.

Step 4: Fix the Computer Fans

I used hot glue to fix the fans. The smaller one needs to be placed over the small heatsink. I used a 24V fan for the inner side of the cooler even tough I'm using a 12V supply. This way, the fan speed is reduced as well as the heat it produced. Your fridge will therefore be a bit more efficient.

Step 5: Wiring the W1209 Digital Thermostat to the Peltier and ATX Breakout Board

It seems a bit scary with all these wires, but it’s really easy to plug everything. You can use the largest wires (I'm using AWG14) to connect the ATX beakout board and the temperature control switch. The red wire connects the 12V rail of the ATX breakout board to the K1 connector of the temperature control switch and the black wire connects the grounds together. The +12V connector of the temperature switch should also be connected to the K1 port in order to power up the switch. I’m using a Dupont cable (in fact 2 cables because it was a bit loose with a single one) to connect these ports together. You can now connect the Peltier and computer fans to the K0 and Gnd connector of the W1209 digital thermostat. Check the wire diagram to make sure that you wired everything properly before turning on the mini fridge!

Step 6: Enjoy Your Mini Fridge!

You can now turn on the ATX breakout board to power your mini fridge. The temperature can be set on the control switch by pressing the set button and then adjusting the value by pressing the +/- keys.

You can access additional settings of the temperature control switch by pressing the set button for a few seconds and then adjusting the desired values. In the table, you can find a list of all the options taken from the W1209 digital thermostat manual.

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    4 Discussions

    Could I use a small 12V power adapter instead of that large computer power supply?

    1 reply

    Sorry for my late reply. Yes, you can use a 12v power supply that can provide enough current for the Peltier module. Instead of the computer power supply, I also used a regular 12V 6A power supply and it worked fine.

    give some mobility to your fridge.. that people can use it at outings.

    1 reply

    That's easy! If you prefer a portable device, you can use a car battery to power the fridge. I have seen some people doing it with success. In this project, I used my homemade lab bench power supply only to maximize the use of recycled computer parts.