Cold Tube offers cool benefits

CANADA: A team of researchers from Canada, USA and Singapore have been exploring a cooling system using chilled water circulating in ceilings and walls. 

Although these types of cooling panels have previously been used in the building industry, what makes the new system different is that it does not need to be combined with a dehumidification system. 

Called the Cold Tube, the technology is being developed by a team of researchers from the University of British Columbia, Princeton University, the University of California, Berkeley and the Singapore-ETH Centre.

“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,” said project co-lead Adam Rysanek, assistant professor of environmental systems at the University of British Columbia’s school of architecture and landscape architecture.

To avoid condensation issues, the researchers have placed a layer of plastic that is mostly transparent to infrared radiation six inches in front of the panel, with desiccant at the bottom to keep the air inside the box dry. 

The team built an outdoor demonstration unit last year in Singapore, inviting 55 members of the public to visit and provide feedback. When the system was running, most participants reported feeling “cool” or “comfortable,” despite an average air temperature of 30ºC.  The panels also stayed dry, thanks to the special membrane.

“Because the Cold Tube can make people feel cool without dehumidifying the air around them, we can look towards shaving off up to 50 per cent of typical air conditioning energy consumption in applicable spaces,” said Eric Teitelbaum, a senior engineer at AIL Research who oversaw the demonstration project while working at the Singapore-ETH Centre.

“This design is ready. It can obviously be used in many outdoor spaces—think open-air summer fairs, concerts, bus stops and public markets. But the mission is to adapt the design for indoor spaces that would typically use central air conditioning,” he added.

Beyond the energy savings, technologies like the Cold Tube have a great future, says project co-lead Forrest Meggers, an assistant professor at Princeton’s school of architecture and the Andlinger Center for Energy and the Environment.

“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,” said Meggers.

In light of the Covid-19 pandemic, the Cold Tube idea could have health benefits. “The idea of staying cool with the windows open feels a lot more valuable today than it did six months ago,” added Adam Rysanek.

The team is currently using the data collected in Singapore to update their projections of the Cold Tube’s effectiveness in indoor spaces globally. They plan to demonstrate a commercially viable version of the technology by 2022.