A small air conditioner

(Deutsche Version) The same cooling method which is used to cool down Bose-Einstein condensates to several nano kelvin is also working in a normal environment. It is called evaporative cooling. Everyone knows this from e.g. a cup of tea, hot water particles evaporate and the temperature drops.

To cool down a room with this principle, you only need water which evaporates. This increases the air humidity but also decreases the temperature. To accelerate the evaporating process, i built the following construction:

A fan (cilence, 92 mm, very silent) is put on stilts in a box of water. The stilts are 6 mm diameter aluminum bars in which I screwed the fan. I would disadvise the usage of wood because it could mould. Afterwards a cloth is wrapped around everything and is secured with a rubber band. The fan pushes air through the wet cloth so the water evaporates. This evaporation needs energy so the temperature drops.

On the right in the image you can see my thermometer I use to measure the air temperature. The temperature of the air coming out of the air conditioner is about 1 degree Centigrade lower than the temperature of the air in my room.