CHINA

New Take On Solar Cooling

Researchers from Hebei University of Technology in China have developed a photovoltaic-thermal (PV/T) air conditioning system that uses an air- cooled condenser and a PV/T condenser combined in series. The system reportedly offers better cooling performance under night conditions.

The novelty of the system consists of using these two components rather than the more commonly used PV/T heat exchanger as the condenser.

“When solar energy and long-wave radiation energy resources are available, the proposed system is suitable regardless of the type of buildings,” researcher Man Fan says. “The system performance is improved by the complementary utilisation of solar energy, air energy and long-wave radiation energy.”

After generating power during the day, the PV/T condenser assists the air-cooled condenser for heat dissipation at night. The system features an evaporator and condenser, a compressor, an electronic expansion valve (EEV), a four-way reversing valve, a gas-liquid separator, and a hot gas bypass valve. It uses R410A refrigerant. ■

Game On For Liquid Cooling

A Spanish firm has integrated industry-grade cooling of gaming PCs into a smartphone. The result for OnePlus is its Active CryoFlux system.

“The state-of-the-art Active CryoFlux system comprises two piezoelectric micropumps connected to pipelines sandwiched between an upper and lower diaphragm,” the Iberian telecommunications firm says. “The piezoelectric micropump, usually reserved for industrial use, delivers the power to circulate the icy cryogenic liquid into the pipelines that take the heat away from the chipset. It dissipates heat without significantly increasing the phone’s weight and thickness.

“The level of innovation in this technology is not to be dismissed,” the firm says. “OnePlus filed more than 30 patents for the fluid diaphragm that forms part of the self-developed Active CryoFlux technology, giving the company a significant market edge when it comes to innovation in active cooling technology geared for smartphones.”

The firm says the two micropumps can fit in a limited space of less than 0.2cm³. ■

Colour Film An Epic Finding

A colour-changing film coating that can be applied to buildings is able to switch between heating and cooling modes. A paper recently published in Nature Sustainability suggests the recently developed film could one day cover buildings with poor thermal performance to help radiate unwanted heat in the summer and trap it during the winter.

The new material starts in cooling mode. Beneath an incredibly thin electrical conductor lies a small reservoir of water with copper ions dissolved inside. In this state, the device naturally radiates heat, cooling the inside of a building.

Then, when the conductor layer applies a small electric charge, the dissolved copper deposits on its surface, forming a thin layer over the reservoir. Because copper emits very little of the mid-infrared heat it absorbs, the device now traps heat. The authors estimate that the technology could save 8.4 per cent of the energy used for heating and cooling in climates that experience a drastic swing in temperatures throughout the year. ■