Silicon valve `will cut air-con energy use by 25%`
A US company, Microstaq, claims to have come up with "the first true revolution in HVAC technology in 50 years" – a miniature silicon valve that, it says, will cut energy consumption in air-conditioning systems by 25%, as well as allowing computer control of fluid movement for the first time. It adds that the silicon expansion valve (SEV) will simplify the design of AC control systems and extend the lives of AC compressors.
Current mechanical expansion control is a 50-year-old technology which needs a large evaporator superheat range, which reduces the evaporator’s heat exchange efficiency. Relatively small changes in ambient conditions can cause the evaporator to deviate from its design performance, resulting in increased energy consumption.
The SEV uses digital controls to respond dynamically to rapidly changing system conditions by metering refrigerant precisely into the evaporator, thus simplifying HVAC system design. It also lowers energy consumption and makes existing mechanical expansion technology "practically obsolete". Microstaq estimates that the product has the potential to cut global energy consumption by more than 1.2 billion barrels of oil per year
"Our customers have been asking for electronic refrigerant expansion control systems that are easy to set up and use, and that are robust enough to stand up to the rigours of high-stress deployments," says Microstaq CEO, Sandeep Kumar. "SEV is a revolutionary leap forward in electronic refrigerant expansion control which will have huge ramifications in the market and is poised to become the industry standard."
Microstaq specialises in MEMS (micro electromechanical systems) for fluid control. The new valve is based on a chip it has developed called Ventilum which, it claims, is the only MEMS device that can cope with fluid movements measured in litres rather than nanolitres as is the case with most rival MEMS devices.
