Air conditioners use massive amounts of energy to cool down homes and offices. As convenient as they may be, they are a significant contributor to global warming. The infamously lousy energy efficiency of air conditioners has motivated scientists from the University of California, Berkeley, the University of British Columbia, the Singapore-ETH Centre, and Princeton University, to develop an environmentally friendly solution.
The team developed a cooling system, dubbed Cold Tube, that absorbs body heat emitted from a person or even a pet, and as a result, it uses around half the energy of traditional systems. They also focused on the dehumidification process, which is a critical function of air conditioning systems.
Adam Rysanek, project co-leader from the University of British Columbia, explained:
Air conditioners work by cooling down and dehumidifying the air around us – an expensive and not particularly environmentally friendly proposition. The Cold Tube works by absorbing the heat directly emitted by radiation from a person without having to cool the air passing over their skin. This achieves a significant amount of energy savings.
Heat naturally releases from hotter surfaces and is attracted to colder surfaces via radiation. The system mirrors this natural phenomenon through an arrangement of rectangle ceiling or wall panels that has chilled water flowing within them. These panels are encased in an airtight membrane that repels humidity to avoid any buildup condensation one might see on a cold glass of water on a warm summer’s day.
Meanwhile, this innovative membrane allows radiation to pass through, which allows the body heat of a person standing near it to radiate towards the panels, resulting in a fresh sensation. As a bonus, there’s no need to dehumidify the air when using this system. Last year, around 55 participants tested out the Cold Tube in Singapore. Even with temperatures at 30°C (86°F), almost all of the participants reported feeling “comfortable” or “cool.”
Eric Teitelbaum, a member of the team who oversaw the demonstration at the Singapore-ETH Centre, said:
Because the Cold Tube can make people feel cool without dehumidifying the air around them, we can look towards shaving off up to 50% of typical air conditioning energy consumption in applicable spaces.
The team highlight that the Cold Tube is ideal for outdoor events, including markets, summer fairs, and concerts. However, their ultimate goal is to develop the system even further so it can be used in place of standard air conditioning in offices and homes.
Forrest Meggers, a co-leader of the project from Princeton University, explained:
Because the Cold Tube works independently of indoor air temperature and humidity, keeping windows open in our increasingly hot summers while still feeling comfortable becomes possible. The Cold Tube can offer relief in different regions, from North American homes and offices that currently rely on standard HVAC systems to developing economies that foresee a significant need for cooling in the coming half-century.
The Cold Tube is described in the journal Proceedings of the National Academy of Sciences (PNAS).
