Abstract: An outdoor unit for an air-conditioning apparatus includes a heat exchanger; a bottom plate; and a separation member configured to separate the bottom plate and the heat exchanger. The bottom plate includes a drainage passage that protrudes downward; and one or more drainage holes each formed to protrude downward from the drainage passage. The drainage passage includes a drainage surface inclined downward toward the one drain hole having a width larger than a width of the heat exchanger. The separation member is formed of a metal electrically less noble than a member forming the heat exchanger, or a resin member. The separation member is provided in the drainage passage and shaped to prevent closing of the drainage passage, in which a height to a surface on which the heat exchanger is placed is larger than a height to an upper surface of the drainage passage.

Abstract: An outdoor unit for an air-conditioning apparatus that includes a bottom plate made of metal, an L-shaped heat exchanger made of metal different than the metal of the bottom plate, a placement plate provided on the bottom plate and having a heat exchanger placement surface on which the heat exchanger is placed. The placement plate having an L-shape in plan view, and the placement plate is held in contact with the bottom plate only below each of a short-side end portion of the placement plate, a long-side end portion of the placement plate, and a corner portion of the placement plate.

Abstract: An outdoor unit for an air-conditioning apparatus includes a heat exchanger; a bottom plate; and a separation member configured to separate the bottom plate and the heat exchanger, the bottom plate including: a drainage passage that protrudes downward; and one or a plurality of drainage holes each formed to protrude downward from the drainage passage, the drainage passage including a drainage surface inclined downward toward the one drain hole having a width larger than a width of the heat exchanger, the separation member being formed of a metal electrically less noble than a member forming the heat exchanger, or a resin member, the separation member provided in the drainage passage and shaped to prevent closing of the drainage passage, in which a height to a surface on which the heat exchanger is placed is larger than a height to an upper surface of the drainage passage.

Abstract: In a heat source-side unit according to the present invention, a temperature sensor is installed on an inter-column connecting part included in a plurality of inter-column connecting parts and located higher than an intermediate position in a vertical direction of a heat exchanger.

Abstract: In an all-aluminum heat exchanger using aluminum as a material of a refrigerant pipe, a dissimilar metal contact with a bottom plate, which is made of iron, of an outdoor unit increases a risk of corrosion of the refrigerant pipe. An outdoor unit for an air-conditioning apparatus includes a placement plate, which is provided on a bottom plate of a casing and has a heat exchanger placement surface having a planar shape on which the heat exchanger is placed. With this configuration, water and dust generated in the casing can be caused to drop from the heat exchanger placement surface to the bottom plate and discharged to an outside of the casing. As a result, even when the all-aluminum heat exchanger is used as a heat exchanger of an air-conditioning apparatus, leakage of refrigerant can be prevented.