A heating, ventilation, and air-conditioning (“HVAC”) system. The HVAC system may include a refrigeration circuit and a blower system. The refrigeration circuit may include a compressor, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger. The blower system may include a first direct-drive blower and a second direct-drive blower. The first direct-drive blower may flow air over the indoor heat exchanger. The second direct-drive blower may flow air over the indoor heat exchanger and the second direct-drive blower may operable and positionable relative to the indoor heat exchanger independently from the first direct-drive blower.

A heating, ventilation, and air-conditioning (“HVAC”) system. The HVAC system may include a refrigeration circuit and a blower system. The refrigeration circuit may include a compressor, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger. The blower system may include a first direct-drive blower and a second direct-drive blower. The first direct-drive blower may flow air over the indoor heat exchanger. The second direct-drive blower may flow air over the indoor heat exchanger and the second direct-drive blower may operable and positionable relative to the indoor heat exchanger independently from the first direct-drive blower.

An axial-flow fan includes a hub that is to be rotated and defines a rotation axis, and a vane provided on a circumference of the hub. The vane includes a leading edge, a trailing edge, an outer circumferential edge, and an inner circumferential edge. The vane is shaped such that a first line chart in a first diagram includes a downward convex portion that is convex further downward than a first virtual line chart, the first virtual line chart being a linear line connecting a point representing a size of an outlet angle formed at a point of the trailing edge that is at the inner circumferential edge and a point representing a size of the outlet angle formed at a point of the trailing edge that is at the outer circumferential edge.

An axial-flow fan includes a hub that is to be rotated and defines a rotation axis, and a vane provided on a circumference of the hub. The vane includes a leading edge, a trailing edge, an outer circumferential edge, and an inner circumferential edge. The vane is shaped such that a first line chart in a first diagram includes a downward convex portion that is convex further downward than a first virtual line chart, the first virtual line chart being a linear line connecting a point representing a size of an outlet angle formed at a point of the trailing edge that is at the inner circumferential edge and a point representing a size of the outlet angle formed at a point of the trailing edge that is at the outer circumferential edge.

A heating, ventilation, and air-conditioning (HVAC) system that includes an outdoor heat exchanger (HX) and outdoor fans. The outdoor fans are arranged in either an in-line configuration or a staggered configuration to satisfy one or more requirements to optimize the airflow across the outdoor HXs.

A heating, ventilation, and air-conditioning (HVAC) system that includes an outdoor heat exchanger (HX) and outdoor fans. The outdoor fans are arranged in either an in-line configuration or a staggered configuration to satisfy one or more requirements to optimize the airflow across the outdoor HXs.

A heating, ventilation, and air-conditioning (HVAC) system that includes an outdoor heat exchanger (HX) and outdoor fans. The outdoor fans are arranged in either an in-line configuration or a staggered configuration to satisfy one or more requirements to optimize the airflow across the outdoor HXs.

A heating, ventilation, and air-conditioning (HVAC) system that includes an outdoor heat exchanger (HX) and outdoor fans. The outdoor fans are arranged in either an in-line configuration or a staggered configuration to satisfy one or more requirements to optimize the airflow across the outdoor HXs.

The air-conditioning apparatus includes a heat exchanger including a plurality of heat transfer tubes and a header manifold an axial fan and a refrigerant circuit. When the distance from the center of the flow space in the horizontal plane is represented on a scale of 0 to 100%, where 0% represents the center of the flow space and 100% is the position of the wall surface of the header manifold, among the plurality of branch tubes located within a height range that allows the blade to rotate, the majority of the branch tubes located at or below the height of the boss are connected to the header manifold such that their distal ends are positioned at 0 to 50% of the distance from the center, and the majority of the branch tubes located above the height of the boss are connected to the header manifold such that their distal ends are positioned at more than 50% of the distance from the center.

An outdoor unit of an air-conditioning apparatus is provided with an outdoor heat exchanger configured to cause refrigerant that flows in the outdoor heat exchanger and air to exchange heat with each other, a plurality of outdoor fans each configured to rotate by driving of a motor and send air to the outdoor heat exchanger, and a controller configured to control the driving of the motor. When operation of one of the plurality of outdoor fans is stopped, the controller is configured to control the motor such that a rotation frequency of each of the plurality of outdoor fans that is in operation after operation of the one of the plurality of outdoor fans is stopped is higher than a rotation frequency of each of the plurality of outdoor fans that is in operation before operation of the one of the plurality of outdoor fans is stopped.