The Peltier air conditioning is worth it

Air conditioning built yourself (part 1)

The hot summer months have already started in Germany and in this country peak temperatures of over 37 ° C have already been reached. Many houses heat up and if you can't call yourself the proud owner of an air conditioning system, you quickly walk into your apartment. High time to build a small air conditioner that will keep our room warm. The weather is bad right now, but you can prepare for the next heat wave - whether for this year or next.
In the first part we will deal with the basic idea and discuss cooling options.

How does air conditioning work?

First of all, there is the very classic construction of an air conditioning system that has to be permanently installed in the house. The functional principle is relatively easy to understand in simplified terms. An air conditioning system for the home always includes two modules, one in the house and one outside the house. First of all, the air conditioning system forms a circuit through which a refrigerant runs. The gaseous refrigerant is compressed by a compressor. The added energy heats the agent, which is then passed through the condenser (the condenser looks similar to a radiator). There the refrigerant cools down and condenses. The contained heat is released into the environment, which means that this part of the system is placed outside the apartment. The agent is then regulated by a pressure valve and then passed through the evaporator. From here the high pressure side of the system ends and the low pressure side begins up to the compressor. In the evaporator, the physical state of the refrigerant changes from liquid to gaseous. To do this, the agent needs energy, which it draws from the environment in the form of heat. The air in the room cools down.

What types of self-made air conditioners are there?

There is also the use of a fan, which only circulates the air and does not cool it down. A cooling feeling only arises because we humans have thin air around us, which is blown away by the fan. In addition, the added air supports the evaporation of sweat on our skin, which removes heat from the body. Then there is the variant of cooling the room with ice cubes and a fan. But this is a common mistake because the freezer cools the ice cubes down and releases the heat to the room in which it is located.
What we learn from this is relatively clear. An air conditioning system does not produce any cold, but instead extracts the thermal energy from the ambient air and then releases it again at another location. And this place has to be somewhere else than the room that is to be cooled. Relatively simple, isn't it?

The idea of ​​a Peltier element

Yes, I know, some experienced people here would like to chase me out of the house, because the efficiency of a TEC is really not good (approx. 10%). Even so, these small parts have amazing properties. By the way, you can find a detailed explanation of how such a Peltier element works here. However, if you are not interested in how it works, here is a brief summary:
A Peltier element is an electronic component that is approx. 4x4x0.5cm in size and has two power connections, a plus and a minus pole. If the Peltier element is connected to a suitable power source, one side becomes very hot and the other very cold. After a few seconds, the element finally overheats. Of course, that shouldn't happen. With good cooling of the warm side, the cold side can also stay cool and, depending on the cooling performance, the opposite side can get -30 ° C.

How can you now use the Peltier element from air conditioning?

Very easily! A heat sink, which is located in the water, is attached to the hot side. On the other side we attach another heat sink, which absorbs the heat. A fan blows warm air through the cold cooling fins, which cools them down.

And the nice thing about it is that these components are very inexpensive. Although they consume a relatively large amount of electricity for a low cooling capacity, this can be accepted in view of the purchase price.

In the next part, I will show you the plan for setting up the air conditioning system and an overview of the costs. The third part will deal with the assembly. And in the fourth and last part I will draw a conclusion on the performance and other anomalies.


Warning !: The presented device works with mains voltage which can be fatal in the event of an electric shock. The instructions shown here are for general information only and may only be reproduced by persons with the appropriate specialist knowledge (electricians, etc.) and under the highest safety measures. I do not accept any liability for damage caused by the manufacture, use or an accident with the device. Anyone who starts with the replica fully agrees to this disclaimer.

Posted in Blog, Do It Yourself, Air Conditioning, TechnologyTagged How It Works, Hot, Cold, Air Conditioning, Cool, Fan, Peltier Element, Electricity, w1209, Efficiency