International News
radiation more efficiently – even at higher temperature and humidity . In addition , the panel consumes far less water than existing designs , so the hydrogel ’ s water supply needs to be replenished far less often .
To test their device ’ s performance , Lu ’ s team placed it over a small patch of the rooftop on MIT ’ s Cambridge campus , alongside a state-of-the-art , purely radiative cooling system . As they hoped , their design performed about three times more effectively than the state-of-the-art system . During summer months , it cooled the space beneath the panel to as much as 9.3 ° C below ambient temperature , even in direct sunlight .
ROAD TO COMMERCIAL ROLLOUT The researchers acknowledge their approach still faces one major challenge before it can be commercialised : cost and scale . Since aerogels are still a relatively new class of material , the techniques required to produce them are often expensive and time-consuming .
In their future research projects , Lu and colleagues will aim to improve on these techniques – possibly through methods like freeze-drying , or the use of entirely new polymer materials to produce the aerogel .
If they succeed , the researchers hope that their approach could lead to a transformation in cooling technology : not only ensuring human comfort as global temperatures rise , but also leading to better systems for preserving and distributing food and medicines .
Lu ’ s team estimates that their passive cooling system could extend the shelf life of food by 40 % in humid climates , and up to 200 % in more arid regions . These benefits could be particularly important for the roughly 10 % of Earth ’ s population who still lack regular access to electricity .
For the rest of the world , it could present a promising new way to tackle global CO 2 emissions – and in the future , it could finally break the cycle of our spiraling consumption of air conditioning .
ARTICLE SOURCE : Department of materials science and engineering & department of mechanical engineering , Massachusetts Institute of Technology . RACA
14
RACA Journal I February 2023 www . refrigerationandaircon . co . za