Introduction: Homemade Peltier Cooler / Fridge With Temperature Controller DIY

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 thin…

How to make a homemade thermoelectric Peltier cooler / mini fridge DIY with W1209 temperature controller. This TEC1-12706 module and the Peltier effect makes the perfect DIY cooler!

This instructable is a step-by-step tutorial showing you how to make your homemade cooler. This DIY fridge uses the Peltier effect, which is the presence of heating or cooling at an electrified junction of two different conductors. Powering the TEC-12706 module will thus generate a cold side and a hot side. The efficiency of this Peltier fridge depends on its ability to efficiently dissipate the cold/heat generated using heatsinks and fans. This video will show you how to use a W1209 digital thermostat to control everything and set the desired temperature on your Peltier cooler.With a similar setup, you can expect a 10-15 Celcius temperature difference between the DIY cooler and ambient temperature. In Fahrenheit, it went from 70 to 50 degrees. For this DIY project, I used the ATX power supply and heatsinks from the computer as well as a Styrofoam cooler box I had, but feel free to use another type of power supply or cooler box. It’s a cool electronic gadget and it's cheap and easy to build! I hope you’ll enjoy!

Please have a look at the next steps to see how to build your own homemade Peltier mini fridge.

You can also check my website for the latest version of this DIY thermoelectric Peltier mini fridge project. I also wrote another post if you want to learn more about Peltier modules and how thermoelectric generators can be used to produce electricity. These Peltier modules are used commercially to build heat powered wood stove fans.

For more information about the power supply that I am using for this project, please have a look at my other Instructables or my youtube video. You can also find more information on my website about the ATX power supply conversion using the ATX breakout board. I hope you will find these tutorials useful.

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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 (, CA, UK, DE, FR) (Aliexpress) (Amazon)

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

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

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

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

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

Disclaimer: As an Amazon, Aliexpress or eBay Affiliate or Associate I can earn a small commission from qualifying purchases. This is anonymous and doesn't cost anything for the buyers.

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.

For more informations, check my video or my tutorial showing you how to build a homemade Peltier cooler / mini-fridge.

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