Busting Conventional Wisdom, when it comes to Peltier devices
Search the internet on Peltier efficiency and the conventional wisdom (Wikipedia, ChatGPT, YouTube, Quora, Reddit, many articles) all pretty much say the same thing: Peltier devices are good for niche applications where their small size, absence of moving parts and ability for precise control offers an advantage, but in general they not efficient, have a low COP (“5% efficiency” is common) and unable to pump significant power. A lot of reasons are postulated, from limitations of the material properties, being too thin (hot and cold sides too close together), some sites talk about ZT values and Carnot efficiency, and some just say they “leak heat”.
Much of this is wrong. It is true that the amount of heat an individual Peltier can efficiently pump heat is limited to around 20-30W, but this is actually quite amazing given the small footprint of a typical device, at just 40x40mm. A good quality TEC1-12708 is capable of 20W cooling/26W heating with just 6W input, yielding efficiency over 300% (COP >3). And with careful design, they can be combined to create more powerful systems as needed.
Also, many applications like refrigeration don’t require much pumping power, with a typical cool box for drinks (read beer) only requiring about 10W, or even less with a well insulated design.
The typical use of Peltier cooler consisting of a large heatsink and cooling fan on the hot side and a tiny block on the cold side is like having a nice car and then driving it around with the handbrake on, finding it sluggish, and then pushing the accelerator and engine really hard to overcome the friction. That style of design, while popular, is basically unsuited for Peltiers. But understanding why isn’t straight forward, and there are many unintuitive aspects when dealing with the Peltier model, temperature, heat flow and materials.
This website is designed to provide the technical materials to help both the home hobbyist and those with serious application (such as in research, product development) to use these cool devices more effectively. It covers:
understanding thermal circuits (temperature, heat flow, thermal resistance, thermal capacity)
understanding the thermal model of the Peltier itself
understanding the thermal model of the whole system (Peltier with heat paths, heat exchanges, objects to be cooled, thermal insulation)
using math or circuit simulators to find configurations and currents that make efficient use of Peltier devices
measurement to confirm the system is working as expected
example set ups for different applications (butter cooler, beer cooler, cool box, air conditioning)
To support the website as a business, it planned to develop tools and set ups for sale that can support users in their own systems, such as precision temperature measurement, flow/heat meters, devices for testing Peltier quality, and pre-made Peltier cells using high quality methods for thermal coupling.
