A/C with no electricity: there's a new plastic for that

Aug 15, 2019

Think about cooling a building with air conditioning that requires no electricity. A team from the University at Buffalo has a patent on a system using a unique plastic on a roof that allows heat to pass through into the sky.

An illustration depicts how the new radiative cooling system might look on a rooftop, with numerous units of the system placed side-by-side to cover a large surface.
Credit Soondi Tech / University at Buffalo

Cooling a summer-hot building is easy. Most people notice the vibrating A/C machinery and hear the mechanism of the equipment close by. Besides the vibration and noise, there is the money needed to cool a building.

But what if there were a way to air condition buildings without all that? UB researchers are looking into that.

"The ideal material for radiant cooling is like a mirror or white paint," said UB Electrical Engineering Associate Professor Qiaoqiang Gan. "They will scatter or reflect most of the solar light. Therefore, the solar light will not heat the object. Then it's easier for us to cool it down."

Gan said the new technology is a mix of a unique new plastic and aluminum boxes.
      
"We actually consume the thermal energy of the Earth, use the natural thermal radiation to the outer space," Gan said, "but since we are cold up there, we have a hot source down here. This is a natural heat transportation process. So we don't need extra energy, extra electricity to make this process happen."
 

Lyu Zhou, UB PhD candidate in electrical engineering, tests the radiative cooling system.
Credit Douglas Levere / University at Buffalo

If a building is in a climate varying from warm to hot, this new system works and does not require all the machinery, costs and electricity of air conditioning. Instead, the warmer and clearer the sky, the more the mechanism pulls heat out of the building into the sky. Reflective glass helps even more, by keeping some heat from coming into the building.

There is one difficulty: the system of special plastic and aluminum boxes works even better if it is warm or hot year round, like Saudia Arabia, where staff from King Abdullah University is working on the project. Gan said his team is still trying to figure out what to do during a Buffalo winter.