June 10, 2025

Bowen Zhou 

10th Grade

John F. Kennedy High School 

Your air conditioner and refrigerator run on what is called a refrigerant. That is how heat is transferred away from your room to the outside, and how your fridge keeps your food cold. The refrigerant absorbs the heat and transfers it away to the outside or to a radiator on the back of your fridge. The constant pumping, compressing, and expanding of the refrigerant is why your AC or fridge costs so much to maintain and use. Around the world, ACs use up to 2,200 terawatt-hours of electricity or 7% of the world's electricity usage yearly. That number will only go up as people’s income increases. If people can afford an AC, then they will buy it, particularly in developing nations.

These refrigerants, if they leak, have the potential to contribute to global warming. Today, we use HFCs or hydrofluorocarbons, which have high global warming potential, but are being phased out with less potent greenhouse gases. The AIM Act tries to address this by phasing out the production and consumption of HFCs. 

But now, with crystal-based cooling, we can cut back on harmful refrigerants and instead use these “plastic crystals”. These crystals were discovered by Jenny Pringle at Deakin University in Australia. These crystals work by transforming under different pressures. When under high enough pressure, they go from randomly organized to aligning themselves. When pressure is removed, they go back to being randomly organized. When they become disordered, the crystals can absorb heat. This technology is not new, however, but most materials had limited cooling capabilities because of the temperatures required. But these new crystals can start cooling in temperatures between -37°C (-34.6°F) and 10°C (50°F). These temperatures are in the range of your AC and refrigerator. The only caveat is that, because of the high-pressure requirements, the conditions would be equivalent to being “thousands of meters underwater”. 

If we can iron out these flaws regarding pressure, and it can be produced on a big enough scale, we can revolutionize how our ACs and fridges work. This can help us reach the 2°C climate target of the Paris Agreement, which is an international treaty addressing climate change.