In Japan, automotive component manufacturers all adopted aluminium heat exchangers before manufacturers in the HVAC&R industry. But with the sustained escalation of copper prices, air conditioner manufacturers have begun ramping up development of aluminium heat exchangers. In February 2009, Corona announced that it had adopted the industry’s first highly anticorrosive aluminium heat exchanger in some Eco Cute heat pump water heater models (on-demand type), which made the units more compact and lighter in weight. This technology was developed in collaboration with the New Energy and Industrial Technology Development Organization (NEDO). On January 26, 2012, Daikin released the Zeas series of heat pump air conditioners incorporating the world’s fi rst all-aluminium microchannel heat exchanger (as reported in the March 2012 issue of JARN). With the 5-hp model, the weight of the outdoor unit was reduced from 80 kg to 59 kg, the lightest in the industry. On July 8, 2013, Mitsubishi Electric announced that it would release 15 models of outdoor units in the Gran-Multi series of VRF systems from October 1, 2013. These models attain the industry’s top annual performance factor (APF) by adopting the world’s first flattened tube heat exchanger in the outdoor unit. Mitsubishi Electric’s flat-tube heat exchanger attains about a 30% improvement in heat transfer efficiency, in part due to additional effects from improved air stream. According to the company, the Gran-Multi series also attains a 2-7% improvement in operating efficiency at low load by optimizing the scroll compressor’s capacity. Thanks to various improvements, the 8-hp model in the new series realizes an APF of 5.9, which is the industry’s top efficiency according to the company.