A free fall simulator comprising: a wind tunnel system; a flight chamber connected to the wind tunnel allowing for a continuous flow of circulating air, and a cooling system for cooling of the air circulating in the wind tunnel system, wherein the cooling system comprises: an air inlet sucking in a part of the air circulating in the wind tunnel system; at least one heat exchanger comprising a coolant; and at least one air outlet adapted such that the cooled air leaves the cooling system through the at least one air outlet. The cooling system further comprises: a closed pressure chamber comprising a cooling area having pressure higher than atmospheric pressure, and at least one auxiliary fan. The at least one heat exchanger is located inside of the closed pressure chamber so that the cooling of the circulating air takes place in the cooling area.

An air-conditioning apparatus according to the present disclosure includes a heat medium circulation circuit, a heat-source-side device, and a voltage drop device. In the heat medium circulation circuit, a pump, an indoor heat exchanger, and a flow control device are connected by pipes to circulate the heat medium. The pump sends a heat medium that contains water or brine and transfers heat. The indoor heat exchanger causes heat exchange to be performed between the heat medium and an indoor air in an air-conditioned space. The flow control device controls a flow rate of the heat medium in the indoor heat exchanger. The heat-source-side device heats or cools the heat medium before the heat medium is sent to the indoor heat exchanger.

The voltage drop device reduces a voltage that is applied to the pump based on a value of a current that is supplied to the pump, in association with a flow rate of the heat medium in the heat medium circulation circuit.

An air-conditioning apparatus according to the present disclosure includes a heat medium circulation circuit, a heat-source-side device, and a voltage drop device. In the heat medium circulation circuit, a pump, an indoor heat exchanger, and a flow control device are connected by pipes to circulate the heat medium. The pump sends a heat medium that contains water or brine and transfers heat. The indoor heat exchanger causes heat exchange to be performed between the heat medium and an indoor air in an air-conditioned space. The flow control device controls a flow rate of the heat medium in the indoor heat exchanger. The heat-source-side device heats or cools the heat medium before the heat medium is sent to the indoor heat exchanger.

The voltage drop device reduces a voltage that is applied to the pump based on a value of a current that is supplied to the pump, in association with a flow rate of the heat medium in the heat medium circulation circuit.

The indoor unit of an air-conditioning unit includes: an opening; a cover; a heat medium heat exchanger; and an air processing unit. The air purge valve is positioned on a rear side in a projection direction of the opening inside the casing. The cover includes, on its one side, a single hook protruding from its cover body. The cover includes, on its side opposite to the one side, a temporarily fixing tab configured to temporarily fix the cover to the casing with the cover body closing the opening.

The indoor unit of an air-conditioning unit includes: an opening; a cover; a heat medium heat exchanger; and an air processing unit. The air purge valve is positioned on a rear side in a projection direction of the opening inside the casing. The cover includes, on its one side, a single hook protruding from its cover body. The cover includes, on its side opposite to the one side, a temporarily fixing tab configured to temporarily fix the cover to the casing with the cover body closing the opening.

An HVAC system includes an indoor heat-exchange coil disposed between a supply air duct and a return air duct. A damper is disposed in a re-circulation duct and is moveable between an open position and a closed position. A controller is configured to determine if the HVAC system is operating in a heating mode or an air-conditioning mode. Responsive to a determination that the HVAC system is operating in the air-conditioning mode, the controller is configured to determine if the variable-speed indoor circulation fan is operating at a minimum speed and if the relative humidity measured by the humidity sensor is above a pre-determined threshold. Responsive to a determination that the variable-speed indoor circulation fan is operating at the minimum speed and the relative humidity of the enclosed space is above the pre-determined threshold, the controller signals the damper to move to the open position.

An HVAC system includes an indoor heat-exchange coil disposed between a supply air duct and a return air duct. A damper is disposed in a re-circulation duct and is moveable between an open position and a closed position. A controller is configured to determine if the HVAC system is operating in a heating mode or an air-conditioning mode. Responsive to a determination that the HVAC system is operating in the air-conditioning mode, the controller is configured to determine if the variable-speed indoor circulation fan is operating at a minimum speed and if the relative humidity measured by the humidity sensor is above a pre-determined threshold. Responsive to a determination that the variable-speed indoor circulation fan is operating at the minimum speed and the relative humidity of the enclosed space is above the pre-determined threshold, the controller signals the damper to move to the open position.

A heat exchanger includes a main pipe through which refrigerant flows, a plurality of tubes connected to the main pipe to allow refrigerant passing through the plurality of tubes to exchange heat with air, and a refrigerant distributor disposed between the main pipe and the plurality of tubes, to distribute refrigerant passing through the main pipe to the plurality of tubes. The refrigerant distributor includes an upstream structure connected to the main pipe and including a plurality of first distribution flow paths to which the refrigerant passing through the main pipe are distributed, and a downstream structure including a plurality of second distribution flow paths communicating with the plurality of first distribution flow paths, and a plurality of refrigerant outlets communicating with the plurality of second distribution flow paths so as to allow the refrigerant to be discharged to the plurality of tubes.

A heat exchanger includes a main pipe through which refrigerant flows, a plurality of tubes connected to the main pipe to allow refrigerant passing through the plurality of tubes to exchange heat with air, and a refrigerant distributor disposed between the main pipe and the plurality of tubes, to distribute refrigerant passing through the main pipe to the plurality of tubes. The refrigerant distributor includes an upstream structure connected to the main pipe and including a plurality of first distribution flow paths to which the refrigerant passing through the main pipe are distributed, and a downstream structure including a plurality of second distribution flow paths communicating with the plurality of first distribution flow paths, and a plurality of refrigerant outlets communicating with the plurality of second distribution flow paths so as to allow the refrigerant to be discharged to the plurality of tubes.

Disclosed is a heat exchanger to reduce height and manufacturing cost. A heat exchanger includes a first heat exchanger provided in the form of a plate; and a second heat exchanger provided in the form of a plate and arranged to be inclined to the first heat exchanger, wherein a corner of at least one of an end of the first heat exchanger and an end of the second heat exchanger is positioned to face a plane of the other of the end of the first heat exchanger and the end of the second heat exchanger.