A new experimental cooling system without electricity is under development from King Abdullah University of Science and Technology (KAUST) in Saudi Arabia. All the system requires is salt and sunlight to cool a space or refrigerate food to temperatures of 3,6ºC.
Large areas of the Middle East lack resources such as drinking water and electricity. This problem requires innovative solutions, often involving alternative resources or new technologies such as drones (the United Arab Emirates has started using rain drones to trigger storms, increase rainfall and cool the region).
Only salt water and sunlight
The KAUST electricity-free cooling system, detailed in an article in the journal Energy and Environmental Science, is another solution that addresses the heat problem… with heat. Or rather, aim to cool using what you have, and in Saudi Arabia you have a lot of sunlight. That's right: KAUST uses the sun to cool buildings.
The experimental installation uses a combination of salt and sunlight to produce its cooling effect for interior spaces.
Most important of all: no electricity is needed.
The machine exploits a natural "phase change" phenomenon which sees energy absorbed when salt crystals dissolve in water. In other words, if salt is added to hot water, the water cools rapidly as the salt dissolves.
KAUST researchers chose the ammonium nitrate due to its high solubility in water and its cooling power, four times greater than ammonium chloride, the "second place". Ammonium nitrate is cheap and is already widespread (e.g. in fertilizers) which also makes it cheap
In their experiments for cooling without electricity, the scientists found that ammonium nitrate could be used to cool the space surrounding a metal cup from room temperature (about 25°C/77ºF) to 3,6°C (38ºF) in about 20 minutes. The temperature then remained below 15°C (59ºF) for more than 15 hours. The KAUST team believes that the system can also be used to cool rooms and food. Salt can be crystallized and reused by evaporating water. Guess how? That's right, always via solar heat.
Cool without destroying the environment: hunt for the air conditioner of the future
Researchers all over the world are trying to develop alternatives to the traditional air conditioner all over the world. It is an absolute necessity to tackle climate change: according to theIEA, air conditioners emit millions of tons of CO2 around the world every day. Purdue University researchers, meanwhile, they developed a Guinness World Record white paint so reflective that it can cool buildings and significantly reduce the need for air conditioning units.
The future is hot, in every sense. It must be cooled with intelligence.
