Traditional automobile AC solutions aren’t always energy efficient but Peltier modules can be used to provide DIY and more serious air conditioning for EVs. Peltier modules are quite versatile in the number of ways they can be used. They can be used to generate electricity, to provide air conditioning or they can be used to provide heating. In fact, Peltier modules make it possible to build versatile heating and cooling devices for applications that require an energy efficiency solution.
What are Peltier Modules?
Peltier modules are thermo electrical devices that are based on the Peltier effect. According to Steven Daly in his book “Automotive air-conditioning and climate control systems,” “the Peltier effect was first discovered in the early 19th century.”
The Peltier effect is observed whenever current passes through two dissimilar electrical conductors. The junction of the two conductors will either absorb or release heat, depending on the direction the current is flowing.
Who discovered the Peltier Effect
Jean Charles Athanase Peltier was a French physicist. He was originally a watch dealer, but at 30 years old took up experiments and observations in the physics.
Peltier was the author of numerous papers in different departments of physics, but his name is specially associated with the thermal effects at junctions in a voltaic circuit. He introduced the Peltier effect. Peltier also introduced the concept of electrostatic induction (1840), based on the modification of the distribution of electric charge in a material under the influence of a second object closest to it and its own electrical charge. This effect has been very important in the recent development of non-polluting cooling mechanisms.
Peltier Air Conditioners for Electric Cars
Electric car converters have long lamented that there is a dearth of energy efficient air conditioning solutions for electric cars. Using a traditional AC compressor to cool an electric car is not an ideal solution because it draws too much power from the batteries, which in effect reduces the driving range of the EV. However, because of the lack of commercially available solutions, EV converters have being using AC solutions similar to these:
- Connect a regular AC compressor to the drive train – This is a simple solution but using this solution tends to reduce the electric car’s driving range. In addition to reducing the driving range, using this setup means that the AC doesn’t work when the car is motionless.
- Using an auxiliary electric motor to power the AC compressor– To ensure that the AC can be turned on when it is needed, an auxiliary motor can be used to power the compressor.
- Using a compact compressor – Masterflux now offers a compact AC compressor that was specially designed for electric cars. It can be found in their Sierra line of products, model# 06-0982Y3 to be exact.
How to Build a Peltier AC Solution
A Peltier air conditioning solution can be built by configuring the Peltier modules to accept a current, which will cool one side of the module and heat the other. In this configuration, Peltier modules are often referred to as TEC or thermoelectric coolers. The hot side of the Peltier module will require a heat sink and a cooling fan to prevent overheating, but these can be easily sourced; even a computer CPU fan will work. The cool side of the Peltier module can then provide cooling by causing the ac fan to blow air across them.
Interestingly, the same modules can also provide heating by changing the direction of the current flow. This will cause the hot side to become cold and the cold side to become hot, which makes Peltier modules an all round heating and air conditioning solution.
Other Uses for Peltier Modules
Due to their flexibility and versatility, Peltier modules can be used in a number of other applications and DIY projects such as generating electricity or cooling a computer’s CPU.