Have you ever thought about cooling a room without using electricity? Now it is possible! In Saudi Arabia, a new experimental powerless cooling system is being developed at King Abdullah University of Science and Technology (KAUST). This is revealed in a press release that outlines the different stages of the project, demonstrating how salt and sunlight can cool a space as large as a bedroom or food to very low temperatures.
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image credit: FOLDER Discovery
One of the issues engineers and scientists have racked their brains over is how to deal with the lack of primary resources in the Middle East. Drinking water and electricity are not available in the region, and it is difficult to supply the various cities of the country in sufficient quantity. It is therefore unnecessary to think about cooling an environment using the usual methods. It is a problem that demands unprecedented innovative solutions.
Scientists at King Abdullah University have come up with an ingenious idea to cool rooms of different sizes in order to combat the desert climate of these regions. Paradoxically, the cooling system is based on the heat of sunlight.
The experimental setup uses a seemingly simple combination, using only salt and sunlight to produce the cooling effect of interior spaces. What is amazing is that this step does not require electricity. The machine makes use of the natural phenomenon of “phase change”, which translates into energy when the salt crystals dissolve in water. In other words, when salt is added to hot water, a chemical reaction causes the water to cool rapidly while the salt dissolves.
It’s all about chemistry …
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image credit: FOLDER Discovery
The researchers at the university realized that the best chemical compound for this project was ammonium nitrate, due to its high solubility in water and its cooling power.
Ammonium nitrate is inexpensive and is already widely used in fertilizers, which means it is a commercially viable option as well. The experiments show that the ammonium nitrate, inside the coverings placed in the walls, is able to cool the environment in approximately 20 minutes, passing from 25ºC to 3.6ºC .
The university team believes their state-of-the-art system can be used to cool buildings and refrigerate food. The salt, once dissolved, can be crystallized again and reused by evaporating the water using solar heat.
In short, it looks like this method could really work and completely change the way we cool rooms. Perhaps it could be the solution to the much wasted energy of air conditioners that almost all of us own …
Source used:
https://pubs.rsc.org/en/content/articlelanding/2021/ee/d1ee01688a