Reinventing air-conditioning

A team from NUS Engineering has invented a next generation air-conditioner that could potentially transform the way air-conditioners have been made in the last century. This game-changing air-conditioner is 40 per cent more energy efficient than our air-conditioners today, and does not require the use of high energy consuming compressors and chemical refrigerants to cool its surroundings.

This breakthrough is a starting point for us to further optimise the air-conditioner and make it more compact with better performance.

Unlike conventional air-conditioners which dehumidify and cool the surrounding air simultaneously, this novel air-conditioner employs two systems which perform the processes separately, achieving greater energy saving. Decoupling the dehumidifying and cooling processes also facilitates better control over them, allowing the air-conditioner to be easily tailored for different weather conditions.

In the first step of the system, ambient air enters a membrane dehumidifying module where the moisture is removed by layers of innovative paper-like membranes. The dehumidified air is then passed through channels of water in the dew point evaporative cooler to produce cool air.


Moisture in the air is removed by layers of paper-like membrane in the air-conditioner's membrane dehumidification module

This new air-conditioner is capable of reaching temperatures of as low as 18 degree Celsius, and it is suitable for both indoor and outdoor use. It is also highly eco-friendly and sustainable.

“Existing air-conditioners discharge a large amount of heat via the compressor. Our system discharges only cool air and does not affect our urban microclimate,” explained Associate Professor Ernest Chua who led the research team. “Using water as the only coolant also removes the need for environmentally harmful refrigerants such as chlorofluorocarbons that would deplete the ozone layer if leaked into the environment.”

Another advantage of the team’s air-conditioner is its ability to harvest clean water from air for repurposing. For every litre of water used to power the cooling system, up to 15 litres of potable water that is five times as pure as the tap water in Singapore can be generated.   

Assoc Prof Chua believes their invention has changed the way air-conditioning is produced. “This breakthrough is a starting point for us to further optimise the air-conditioner and make it more compact with better performance,” he said.

The team is currently working on improving the user-friendliness of the air-conditioning system, as well as looking into incorporating smart features such as real-time tracking of energy efficiency.   

See press release and media coverage.