An induction displacement unit comprising an induction plenum comprising a plurality of first nozzles communicating with a first discharge plenum and a plurality of second nozzles communicating with a second discharge plenum, a return air plenum, a heating coil disposed between the return air plenum and the first discharge plenum, a cooling coil disposed between the return air plenum and the second discharge plenum, the induction plenum vertically disposed between the heating coil and the cooling coil, the heating coil disposed in an upper portion of the unit, the first discharge plenum disposed to induce a substantially vertical discharge, and the second discharge plenum disposed to induce a substantially horizontal discharge.

An object of the present invention is to allow uniform distribution of a refrigerant by a distributor. A refrigerant pipe includes a bent pipe formed in the shape of a curve and a downstream pipe connected to the downstream side of the bent pipe and formed to be linear. A distributor to distribute the refrigerant into a plurality of flow paths is connected to the downstream pipe on the downstream side. An inner wall on the inner peripheral side of the bent pipe being on the side of the curvature center of the curve is a grooved surface with a groove formed therein, and an inner wall on the outer peripheral side of the bent pipe being on the side opposite to the curvature center of the curve is a smooth surface.

An object of the present invention is to allow uniform distribution of a refrigerant by a distributor. A refrigerant pipe includes a bent pipe formed in the shape of a curve and a downstream pipe connected to the downstream side of the bent pipe and formed to be linear. A distributor to distribute the refrigerant into a plurality of flow paths is connected to the downstream pipe on the downstream side. An inner wall on the inner peripheral side of the bent pipe being on the side of the curvature center of the curve is a grooved surface with a groove formed therein, and an inner wall on the outer peripheral side of the bent pipe being on the side opposite to the curvature center of the curve is a smooth surface.

Operation switching units, each changing directions of a refrigerant flowing through its associated indoor unit in response to a switch from a cooling operation to a heating operation, or vice versa, are each connected with the associated indoor unit through indoor communication pipes; a gas-liquid separation unit is connected with an outdoor unit through outdoor communication pipes; and the operation switching units are connected with the gas-liquid separation unit through two intermediate communication pipes preinstalled and one intermediate communication pipe newly installed. This provides a simple and cost-effective means for upgrading a preinstalled air conditioner making a switch from cooling to heating, and vice versa, into an air conditioner that can perform a cooling operation and a heating operation in parallel with each other.

Operation switching units, each changing directions of a refrigerant flowing through its associated indoor unit in response to a switch from a cooling operation to a heating operation, or vice versa, are each connected with the associated indoor unit through indoor communication pipes; a gas-liquid separation unit is connected with an outdoor unit through outdoor communication pipes; and the operation switching units are connected with the gas-liquid separation unit through two intermediate communication pipes preinstalled and one intermediate communication pipe newly installed. This provides a simple and cost-effective means for upgrading a preinstalled air conditioner making a switch from cooling to heating, and vice versa, into an air conditioner that can perform a cooling operation and a heating operation in parallel with each other.

The present application provides a heat exchange device, which includes: a fluid passage; and two or more heat exchangers, each heat exchanger having a thermal connection with the fluid passage and having an input pipeline and an output pipeline respectively, wherein each input pipeline and each output pipeline are configured to be selectively communicated and closed, and wherein each input pipeline is connected to all other input pipelines through input branch pipe(s), and each output pipeline is connected to all other output pipelines through output branch pipe(s); each input branch pipe and each output branch pipe are configured to be selectively communicated and closed. The heat exchange device of the present application has the advantages such as simple in structure, easy for manufacturing, and convenience in use. The efficiency of heat exchange can be effectively improved, and additional operating modes are provided, thereby improving the user experience.

The present application provides a heat exchange device, which includes: a fluid passage; and two or more heat exchangers, each heat exchanger having a thermal connection with the fluid passage and having an input pipeline and an output pipeline respectively, wherein each input pipeline and each output pipeline are configured to be selectively communicated and closed, and wherein each input pipeline is connected to all other input pipelines through input branch pipe(s), and each output pipeline is connected to all other output pipelines through output branch pipe(s); each input branch pipe and each output branch pipe are configured to be selectively communicated and closed. The heat exchange device of the present application has the advantages such as simple in structure, easy for manufacturing, and convenience in use. The efficiency of heat exchange can be effectively improved, and additional operating modes are provided, thereby improving the user experience.

A system and method that optimizes energy consumption in an HVAC unit by minimizing chiller activity. The system uses a control unit that overrides a thermostat in at least one room to close a cooling valve that leads a fluid input to the room. When multiple cooling valves are closed through the rooms, the consequential return fluid maintains greater cooling capacity and thus, the chiller does not have to operate at full capacity. The control unit individually controls components in the HVAC unit, which were previously controlled by switches on the thermostat. The control unit includes a temperature sensor that monitors an environment, such as the room and a plenum. The control unit also includes a control relay that closes the cooling valve on the HVAC unit when the predetermined temperature of the control unit is above the thermostat temperature set by a room occupant.

A system and method that optimizes energy consumption in an HVAC unit by minimizing chiller activity. The system uses a control unit that overrides a thermostat in at least one room to close a cooling valve that leads a fluid input to the room. When multiple cooling valves are closed through the rooms, the consequential return fluid maintains greater cooling capacity and thus, the chiller does not have to operate at full capacity. The control unit individually controls components in the HVAC unit, which were previously controlled by switches on the thermostat. The control unit includes a temperature sensor that monitors an environment, such as the room and a plenum. The control unit also includes a control relay that closes the cooling valve on the HVAC unit when the predetermined temperature of the control unit is above the thermostat temperature set by a room occupant.

A refrigeration system, when a set evaporator water outlet temperature T.sub.o is less than a daily minimum temperature T.sub.min, starts a cold water unit to cool a cooling pool; when the set evaporator water outlet temperature T.sub.o is greater than a daily maximum temperature T.sub.max, starts a natural cooling source to cool the cooling pool; when T.sub.min≤T.sub.o≤T.sub.max, if T.sub.i≥T.sub.o−a set value, starts the cold water unit to cool the cooling pool, and if T.sub.i<T.sub.o−the set value, starts the natural cooling source to cool the cooling pool. The refrigeration system not only satisfies the cooling requirements of the cooling pool, but also achieves the purpose of saving energy, reducing costs.