An aluminum fin material includes an aluminum plate, an erosion-resistant coating layer on a surface of the aluminum plate, and a hydrophilic coating layer formed on a surface of the erosion-resistant coating layer. The erosion-resistant coating layer contains an acrylic resin and fluororesin particles, an amount of the erosion-resistant coating layer is 0.05 mg/dm.sup.2 or more and 8.00 mg/dm.sup.2 or less, and a content of the fluororesin particles in the erosion-resistant coating layer is 0.05 mass % or more and 8.00 mass % or less.

A heat exchanger, a heat exchanger unit, and a refrigeration cycle apparatus improve a heat exchange performance, a discharge performance, and a frosting resistance, and each include: a flat tube; a fin formed in the shape of a plate having a plate surface extending in a longitudinal direction of the fin that is perpendicular to a width direction thereof, coincides with an up/down direction, and crosses the tube axis of the flat tube; and a first water conveyance member provided below the fin. The first water conveyance member has: a first upper surface facing a lower end portion of the fin; a first ridge located at one end portion of the first upper surface; and a second ridge located at the other end portion of the first upper surface.

A heat exchanger, a heat exchanger unit, and a refrigeration cycle apparatus improve a heat exchange performance, a discharge performance, and a frosting resistance, and each include: a flat tube; a fin formed in the shape of a plate having a plate surface extending in a longitudinal direction of the fin that is perpendicular to a width direction thereof, coincides with an up/down direction, and crosses the tube axis of the flat tube; and a first water conveyance member provided below the fin. The first water conveyance member has: a first upper surface facing a lower end portion of the fin; a first ridge located at one end portion of the first upper surface; and a second ridge located at the other end portion of the first upper surface.

A brazed plate heat exchanger (100) including a plurality of first and second heat exchanger plates (110, 120), wherein the first heat exchanger plates (110) are formed with a first pattern of ridges (R1) and grooves (G1), and the second heat exchanger plates (120) are formed with a second pattern of ridges (R2a, R2b) and grooves (G2a, G2b) providing contact points between at least some crossing ridges and grooves of neighbouring plates under formation of interplate flow channels for fluids to exchange heat, said interplate flow channels being in selective fluid communication port openings (O1, O2, O3, O4). The first pattern of ridges and grooves is different from the second pattern of ridges and grooves, so that an interplate flow channel volume on one side of the first heat exchanger plates (110) is different from the interplate flow channel volume on the opposite side of the first heat exchanger plates (110). The heat exchanger (100) is provided with a retrofit port heat exchanger (400). A system and a method are also disclosed.

A heat exchanger of a heat-source-side unit includes: a heat exchange unit where heat transfer tube groups, each of which includes a plurality of heat transfer tubes arranged in a vertical direction, are provided in an air passage direction in at least three or more rows; a liquid-side connecting pipe forming an inlet or an outlet for refrigerant in a liquid phase or in a gas-liquid two phase; and a distributor configured to distribute the refrigerant to a plurality of refrigerant flow passages forming the heat exchange unit. In at least two heat transfer tube groups of the heat transfer tube groups of the heat exchange unit, the liquid-side connecting pipe is connected to one end of a heat transfer tube located at least at a lowermost portion of each of the two heat transfer tube groups and the distributor is connected to the other end of the heat transfer tube.

A heat exchanger of a heat-source-side unit includes: a heat exchange unit where heat transfer tube groups, each of which includes a plurality of heat transfer tubes arranged in a vertical direction, are provided in an air passage direction in at least three or more rows; a liquid-side connecting pipe forming an inlet or an outlet for refrigerant in a liquid phase or in a gas-liquid two phase; and a distributor configured to distribute the refrigerant to a plurality of refrigerant flow passages forming the heat exchange unit. In at least two heat transfer tube groups of the heat transfer tube groups of the heat exchange unit, the liquid-side connecting pipe is connected to one end of a heat transfer tube located at least at a lowermost portion of each of the two heat transfer tube groups and the distributor is connected to the other end of the heat transfer tube.

A heat exchanger for an air conditioner for which a zeotropic refrigerant mixture is used is obtained, and the heat exchanger, when used as an evaporator, enables reduction of the amount of required refrigerant without deteriorating the heat transfer performance. The heat exchanger includes: a plurality of fins stacked together at predetermined intervals therebetween; first heat transfer pipes which extend through the plurality of fins, in which a heat medium flows, and which have a plurality of grooves in the inner surface of the pipes; and second heat transfer pipes extending through the plurality of fins, having one end connected to one end of the first heat transfer pipes to form one heat medium flow path, being smaller in pipe diameter than the first heat transfer pipes, and having an inner surface shape providing a pressure loss per unit length smaller than that of the first heat transfer pipes.

A heat exchanger for an air conditioner for which a zeotropic refrigerant mixture is used is obtained, and the heat exchanger, when used as an evaporator, enables reduction of the amount of required refrigerant without deteriorating the heat transfer performance. The heat exchanger includes: a plurality of fins stacked together at predetermined intervals therebetween; first heat transfer pipes which extend through the plurality of fins, in which a heat medium flows, and which have a plurality of grooves in the inner surface of the pipes; and second heat transfer pipes extending through the plurality of fins, having one end connected to one end of the first heat transfer pipes to form one heat medium flow path, being smaller in pipe diameter than the first heat transfer pipes, and having an inner surface shape providing a pressure loss per unit length smaller than that of the first heat transfer pipes.

A dust hood, useful for use in the compressed air and vacuum cleaning of a dusty apparatus placed therein, which is in the form of a flexible bag having a portion of its front face transparent with that front face also containing holes for a hose supplying compressed air and a hose supplying vacuum, respectively, for such cleaning.

Provided is a refrigerant distributor including: a first space forming portion having a first refrigerant port and a second refrigerant port; and a second space forming portion, which extends laterally from a lower part of the first space forming portion, and has a plurality of heat transfer pipe connecting portions. A gas-liquid refrigerant mixture flows into the first space forming portion through the first refrigerant port. Heat transfer pipes are connected at positions of the plurality of heat transfer pipe connecting portions in the second space forming portion.