A Cooling System that Doesn’t Need Electricity?

By Ariana Nieves,
Sustainable Investment Group (SIG)

Image of house in treesAs the battle with climate change continues a big question is how we will cool our buildings in the future. According to researchers, in 2019 alone cooling devices contributed to 8.5 percent of the world’s total energy consumption. That is about one billion tons of CO2 emissions generated in just one year and the demand for cooling systems is only getting higher.

To combat this issue, MIT has been experimenting to create a sustainable alternative. MIT has recently been looking into a passive device that would not utilize any electricity. The technology takes in heat from its surroundings and then uses physical effects to move the heat away from the system being cooled. If successful, this device could help alleviate cooling system energy consumption.

How It Works

The device is a flat panel made up of 3 different layers that combine various cooling techniques. The first layer consists of a highly insulating aerogel; it is an ultralight material that is almost sponge-like. The aerogel contains scattered networks of cross-linked polymers that creates a large volume of empty space.

The second layer is made up of hydrogel, this is a similar material to the aerogel except its polymers are insoluble and saturated in water. This layer is covered by the aerogel above, however when thermal energy does pass through it, the water is partly evaporated into vapor. The vapor then rises through the aerogel layer.

The final layer consists of a reflective material that acts like a mirror. The layer reflects the heat and passes it through the other two layers to guarantee the hydrogel absorbs as much thermal energy as possible.

MIT researchers then placed the device on a campus rooftop next to a radiative cooling system to test its performance. The researchers found that the passive device was three times as effective as the standard radiative cooling system. During the summer months under direct sunlight, the panel cooled the space underneath it to about 49℉ below room temperature.

The passive cooling system is functional and even more effective than traditional cooling systems. The device created by MIT could become a feasible sustainable alternative in the future; potentially preventing thousands of tons of carbon emissions from polluting the earth. 

Sources:

https://www.domusweb.it/en/sustainable-cities/2022/10/19/from-mit-comes-a-new-passive-cooling-system.html 

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