Abstract: A compressor (21), a heat exchanger (30), a demoisturizer (22), and an expansion device (23) are duct connected in that order to form a heat source-side system (20). The compressor (21) draws and compresses outdoor air and exhaust air for ventilation. The compressed air is subjected to heat exchange with air for conditioning in the heat exchanger (30). The compressed air is demoisturized in the demoisturizer (22). Thereafter, the compressed air is expanded in the expansion device (23), changes to low-temperature air, and then is expelled to outside the room. On the other hand, the conditioning air is delivered, through an inlet duct (43), to the heat exchanger (30). The conditioning air is a mixture of supply air for ventilation and air in the room. The conditioning air is subjected to heat exchange with the compressed air in the heat exchanger (30), whereby the conditioning air is heated. Further, the conditioning air is humidified in a humidifying part (42).

Abstract: A method for forming light-weight composite metal castings incorporating metallurgically bonded inserts for a variety of applications. Castings formed by the invention have particular utility as components of an internal combustion engine. A casting method includes the step of coating the insert with a first layer under conditions including sufficient temperature to cause a portion of the layer to be sacrificed by dissolving into the cast metal material while leaving at least a portion of the first layer as a diffusion barrier between the insert and the cast material. The molten casting material is treated and handled to keep the hydrogen content below 0.15 and preferably below 0.10 parts per million. The casting step takes place under a protective gas environment of dry air, argon or nitrogen with a moisture content of less than 3 parts per million.