A variable refrigerant flow (VRF) system for a building. The VRF system includes at least one outdoor VRF unit configured to heat or cool a refrigerant for use in heating or cooling the building. The at least one outdoor VRF unit includes a sub-cooler and a bypass expansion valve configured to control a flow of the refrigerant through the sub-cooler and an extremum-seeking controller configured to generate a sub-cooling temperature setpoint for the at least one outdoor VRF unit. The extremum-seeking controller is configured to determine a total power consumption of the at least one outdoor VRF unit, generate a sub-cooling temperature setpoint for the at least one outdoor VRF unit using an extremum-seeking control technique that drives the total power consumption toward an extremum, and use the sub-cooling temperature setpoint to operate the at least one outdoor VRF unit.

A liquid desiccant air conditioning system comprises an energy exchange unit comprising a sump and a plurality of media pads positioned above the sump, first, second, and third desiccant outlets fluidly connected to the sump, and at least one retractable gate positioned above the sump, configured to partition the sump into at least first and second compartments, wherein the first compartment is fluidly connected to the first desiccant outlet and the second compartment is fluidly connected to the second desiccant outlet, and wherein effective volumes of the first and second compartments can be modified by opening and closing the at least one retractable gate. A method of controlling desiccant circulation in a liquid desiccant air conditioning system is also described.

A liquid desiccant air conditioning system comprises an energy exchange unit comprising a sump and a plurality of media pads positioned above the sump, first, second, and third desiccant outlets fluidly connected to the sump, and at least one retractable gate positioned above the sump, configured to partition the sump into at least first and second compartments, wherein the first compartment is fluidly connected to the first desiccant outlet and the second compartment is fluidly connected to the second desiccant outlet, and wherein effective volumes of the first and second compartments can be modified by opening and closing the at least one retractable gate. A method of controlling desiccant circulation in a liquid desiccant air conditioning system is also described.

A liquid desiccant air conditioning system comprises an energy exchange unit comprising a sump and a plurality of media pads positioned above the sump, first, second, and third desiccant outlets fluidly connected to the sump, and at least one retractable gate positioned above the sump, configured to partition the sump into at least first and second compartments, wherein the first compartment is fluidly connected to the first desiccant outlet and the second compartment is fluidly connected to the second desiccant outlet, and wherein effective volumes of the first and second compartments can be modified by opening and closing the at least one retractable gate. A method of controlling desiccant circulation in a liquid desiccant air conditioning system is also described.

It is an object to obtain an air conditioner capable of suppressing rise of compressor discharge temperature and individually controlling cooling capacity of a plurality of respective indoor units. For this purpose, the air conditioner is a multi-room air conditioner, in which a refrigeration cycle is formed by connecting an outdoor unit 100 having an outdoor heat exchanger to the plurality of indoor units 200 and 300 having indoor heat exchangers 201 and 301 and indoor expansion mechanisms 203 and 303 using a liquid pipe 121 and a gas pipe 122. Further, as refrigerant circulating through the refrigeration cycle, R32 or mixed refrigerant containing 70 mass % or higher percent of R32 is used. Further, a temperature difference detection device to detect an air temperature difference between inlet-side air and outlet-side air in the respective indoor heat exchangers of the respective indoor units is provided. The cooling capacity in the respective indoor units is controlled by regulating the indoor expansion mechanisms of the respective indoor units based on the air temperature difference in the indoor units detected with the temperature difference detection device.

It is an object to obtain an air conditioner capable of suppressing rise of compressor discharge temperature and individually controlling cooling capacity of a plurality of respective indoor units. For this purpose, the air conditioner is a multi-room air conditioner, in which a refrigeration cycle is formed by connecting an outdoor unit 100 having an outdoor heat exchanger to the plurality of indoor units 200 and 300 having indoor heat exchangers 201 and 301 and indoor expansion mechanisms 203 and 303 using a liquid pipe 121 and a gas pipe 122. Further, as refrigerant circulating through the refrigeration cycle, R32 or mixed refrigerant containing 70 mass % or higher percent of R32 is used. Further, a temperature difference detection device to detect an air temperature difference between inlet-side air and outlet-side air in the respective indoor heat exchangers of the respective indoor units is provided. The cooling capacity in the respective indoor units is controlled by regulating the indoor expansion mechanisms of the respective indoor units based on the air temperature difference in the indoor units detected with the temperature difference detection device.

Systems and methods are disclosed for a cogeneration system for providing heating, cooling, and/or electricity to an enclosure. The system includes a heat engine for heating and supplying electricity to the enclosure through fluid transfer from the heat engine to the enclosure to transfer thermal energy from the fluid to the enclosure. The system further includes a heat pump configured to supply at least heating and cooling to the enclosure through movement of fluid from the heat pump to the enclosure to transfer thermal energy from the fluid to the enclosure.

Systems and methods are disclosed for a cogeneration system for providing heating, cooling, and/or electricity to an enclosure. The system includes a heat engine for heating and supplying electricity to the enclosure. Coupled to the heat engine is a first conduit configured to transfer fluid from the heat engine to the enclosure to transfer thermal energy from the fluid to the enclosure. The system further includes a heat pump configured to supply at least heating and cooling to the enclosure. Coupled to the heat pump is at least a second conduit. The second conduit is configured to move fluid from the heat pump to the enclosure to transfer thermal energy from the fluid to the enclosure.

Systems and methods are disclosed for a cogeneration system for providing heating, cooling, and/or electricity to an enclosure. The system includes a heat engine for heating and supplying electricity to the enclosure. Coupled to the heat engine is a first conduit configured to transfer fluid from the heat engine to the enclosure to transfer thermal energy from the fluid to the enclosure. The system further includes a heat pump configured to supply at least heating and cooling to the enclosure. Coupled to the heat pump is at least a second conduit. The second conduit is configured to move fluid from the heat pump to the enclosure to transfer thermal energy from the fluid to the enclosure.

Systems and methods are disclosed for a cogeneration system for providing heating, cooling, and/or electricity to an enclosure. The system includes a heat engine for heating and supplying electricity to the enclosure. Coupled to the heat engine is a first conduit configured to transfer fluid from the heat engine to the enclosure to transfer thermal energy from the fluid to the enclosure. The system further includes a heat pump configured to supply at least heating and cooling to the enclosure. Coupled to the heat pump is at least a second conduit. The second conduit is configured to move fluid from the heat pump to the enclosure to transfer thermal energy from the fluid to the enclosure.