In the hot 2018 summer I decided to build something to cool down my garage (you saw some picture of in in my videos on youtube). I have no space for the external motor of a real air conditioned system so I had the need to find a quick solution. The only thing I was able to do was to extract from the garage the air collected from a specific place. This was possible because of a powerful fan installed few months before, used to refresh the air in the room.

Now i said to myself ... why if I collect in that specific place all the hot air produced by a Peltier cell? or by a set of more Peltier cells?

Let me explain you before what is a Peltier cell.

A Peltier cell is a specific component found by Mr. Jean Charles Athanase Peltier with an incredible characteristic. If you send a specific current in it you will always have a Delta(t) of difference in temperature between the two surface

So, this "object" has two separate faces. To simplify the description we will call the first one: "cold surface" and the second one: "hot surface".

Now imagine what can happen if you are able to cool down the hot surface. It will happen that also the cold surface will decrease its temperature. This because the difference of temperature between the two surfaces (Delta(t)) will always and forever remain the same (if a current comes trough the cell obviously).

So, just to make you an example. If the Delta(t) = 15 and the current temperature of the hot surface is 20 degrees, when you connect the cable to a power supply you will have 20 degrees on the hot side and 5 on the cold side. The hot side will increase the temperature so also the cold side will increase it. Now if you are able to maintain the hot side to 20 degrees (or cooler), you will be able to have the cold side to 5 or cooler.

In order to cool down the hot surface you can use different methods. First of all the two sides must be separate more than possible and isolated. Then you need to use aluminium to cool down the surface. The aluminium can be cooled down using fan or using water or any other liquid you want.

Application of Peltier cells are different. Many manufacturers use those cells to cool down servers or gaming PC. I decided to try this experiment so I decided to build a small air conditioned system.

Please note. I did it just for fun and because I have no external space for the motor of a real air conditioned system. Peltier cells cannot obtain the same efficiency of a real air conditioned system because the hot air remain into the room (it is just extracted). You can cool down the temperature of just few degrees so, do it only if you want to play with this interesting component

For my experiment I bought from Ebay the following 3 cells hardware:

You can find it for few euros. Usually this is a 12V systems that requires different Amps to run cells and Fans (there are 6 fans. 3 on each side)

Based on this consideration the main need was to clearly separate the two surface and collect the hot air in a place where I could connect the pipe linked to the extractor fan (remember, at the beginning of the discussion I said that few months ago I installed a fan to change the air into the room)

For this reason I draw this box. The hot air is collected in the box. The box is then connected to the fan with a 10CM Pipe. To close the top of the box I used black silicon that is more useful in case of high temperature. The box has been printed using my Printerina 3D printer and connected (this is just a plus) to the Miniservice infrastructure in order to be turned on and off from the internet using the BV IoT Manager web application.

The air is suck in the box thanks to the wholes I draw in it. This allow a great air circulation, the flow direction is studied to go directly on the aluminium cooled down by the fans.
With this configuration, the cold side remains really cold and can better distribute the air in the room.

In the following 2 images you can see how it fits perfectly the extractor fan I have installed to push out of the room the hot air produced by the system. Obviously the extractor works well also when the Air conditioned system is not activated.

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NOTE AGAIN: This system cannot replace a real air conditioned system. You can use it just to cool down the temperature of few degrees and the efficiency is very low so build it only if you want to have fun with electronic stuff.

If you want to download STL files used to print this system you can go to the thingiverse web site here: