Versatile Heating/Cooling Plate with Triple Peltier Elements

This is a home-built device that uses three Peltier elements. It can electrically switch between heating and cooling mode of operation.

Possible Applications

• Small beverage chiller/warmer to keep a drink cold (or a mug of coffee warm) on your desk.
• Science experiments.
• Hobby prototyping: Great for testing sensors or components under controlled temperature environments.

A Peltier element (also called a thermoelectric cooler or TEC) moves heat from one side of the device to the other when powered. If you feed the module current in one direction, one side cools while the other side heats. Reverse the polarity, and the hot/cold sides flip.

In short, they offer a neat, compact way to generate small-scale heating or cooling without traditional refrigerants or compressors and it has no moving parts.

!WARNING! I'm reusing USB-A connector here in completely incompatible ways to power current device with 12 volts also from DIY power supply. You should never connect this device to normal USB power supplies because it likely will destroy it and will be fire hazard!

My DIY device consists of the following major parts:

• Three Peltier modules, arranged on top of one-another for a higher overall cooling/heating capacity.
• A top plate, where items are placed for heating or cooling.
• A fan assembly on the opposite side of the Peltiers to pull air across a heatsink.
• A mode switch (Heating/Cooling), which toggles the polarity of the Peltier elements.
• An On/Off switch that powers the entire system.
• Two indicator LEDs: one lights up for “Heating” mode, the other for “Cooling” mode.

In simple terms, you have a box with a top-most Peltier element for contacting the item to be warmed or cooled. Inside, there’s a set of Peltier modules sandwiched between and an internal heatsink, with a fan that moves air over the heatsink. The two switches handle power and polarity, and the LEDs offer instant visual feedback.

By wiring three Peltier elements, the cooling/heating capacity is effectively multiplied.

A crucial factor in making Peltiers work well is how effectively you dump the waste heat/cold on the opposite end of the Peltier stack into the environment. If the hot side is not kept sufficiently cool, the effectiveness of the entire module drops.

• FreeCAD design file

3D printable STL files:

• DISCLAIMER: I DO ELECTRONICS AND 3D DESIGN SOLELY AS A HOBBY. THERE COULD BE ERRORS THAT CAN RESULT IN ALL KINDS OF DAMAGE. USE THESE DESIGNS AT YOUR OWN RISK.
• This design is released under Creative Commons Zero (CC0) license.
• Author:
  • Svjatoslav Agejenko
  • Homepage: https://svjatoslav.eu
  • Email: svjatoslav@svjatoslav.eu
• See also:
  • Other physical projects in this repository
  • Other projects hosted at svjatoslav.eu