Abstract: A core includes heat-exchange tubes and radiation fins are alternately stacked on each other. The heat-exchange tubes define refrigerant passages. A header tank is connected to the heat-exchange tubes. A partition separates the header tank into first and second header chambers to turn a refrigerant. The partition defines a communication hole allowing the first and second header chambers to communicate with each other.

Abstract: A flat tube includes pairs of dimple portions in a longitudinal direction thereof. Each of the pairs has a first dimple portion and a second dimple portion, which are slanted with respect to an intermediate line extending in the longitudinal direction at an intermediate position in a lateral direction so that inner end wall portions of the first and second dimple portions are located on the intermediate line, and so that the outer end wall potions thereof depart from the intermediate line in the lateral direction to be toward outer sides of the tube, respectively. The pairs of dimple portions are set to satisfy a relationship expressed by an inequality: 3?L2/L1?12, where L1 is a longitudinal projection length obtained by projecting one of the first and second dimple portions on the intermediate line, and L2 is a longitudinal pitch between adjacent pairs.

Abstract: A pure water tank reduces stress to be applied to the tank when pure water in the tank freezes, to thereby prevent the deformation or breakage of the tank without thickening the wall of the tank. The tank has inner side-walls to define a pure water zone. On the outer side of the inner side-walls, an antifreeze zone is defined. The antifreeze zone holds antifreeze having a freezing point lower than a lowest temperature of a service temperature range of the tank. The density of the antifreeze increases as the temperature thereof decreases. The width of the antifreeze zone is set to satisfy D?? loge(H)+d0, where H is the height of the antifreeze zone.

Abstract: A core includes heat-exchange tubes and radiation fins are alternately stacked on each other. The heat-exchange tubes define refrigerant passages. A header tank is connected to the heat-exchange tubes. A partition separates the header tank into first and second header chambers to turn a refrigerant. The partition defines a communication hole allowing the first and second header chambers to communicate with each other.

Abstract: A pure water tank reduces stress to be applied to the tank when pure water in the tank freezes, to thereby prevent the deformation or breakage of the tank without thickening the wall of the tank. The tank has inner side-walls to define a pure water zone. On the outer side of the inner side-walls, an antifreeze zone is defined. The antifreeze zone holds antifreeze having a freezing point lower than a lowest temperature of a service temperature range of the tank. The density of the antifreeze increases as the temperature thereof decreases. The width of the antifreeze zone is set to satisfy D?? loge(H)+d0, where H is the height of the antifreeze zone.