An air conditioning system includes a heat pump section performing indoor air-warming by using a vapor-compression refrigeration cycle, a separate heat source section performing indoor air-warming by using a heat source separate from the heat pump section, and a control unit configured to control actions of the heat pump section and the separate heat source section. When a heat pump air-warming operation is being performed, and when a first switching condition is met, the control unit switches from the heat pump air-warming operation to a separate heat source air-warming operation. The first switching condition is that an outside air temperature reaches a first switching outside air temperature and an air-warming capability of the heat pump section reaches an upper limit.

A sealed refrigeration system and appliance are provided. The sealed refrigeration system may include a compressor, a condenser, an evaporator, and a check valve assembly. The compressor may be operable to compress refrigerant, while the condenser may be disposed in downstream fluid communication with the compressor to condense refrigerant received from the compressor. The evaporator may be disposed in fluid communication between the condenser and the compressor. The check valve assembly may be disposed in fluid communication between at least two components of the sealed refrigeration system. The check valve assembly may include a valve body defining a circuit inlet, a circuit outlet, and a charge port. The circuit outlet may be downstream from the circuit inlet to direct refrigerant therefrom. The charge port may be between the circuit inlet and the circuit outlet to receive refrigerant therethrough.

A system and method for climate control of an environment in a building are provided. The system includes a first loop and second loop for circulating a heating medium. The system also includes a boiler, an energy optimizer and a controller. The method involves circulating a heating medium, providing heat to the heating medium, and controlling the boiler based on various inputs.

A heat pump system according to an aspect of the disclosure may comprise: a compressor configured to compress a refrigerant; a water heat exchanger configured to exchange heat between the compressed refrigerant and introduced water; an expansion valve configured to expand the refrigerant condensed in the water heat exchanger; an outdoor heat exchanger configured to exchange heat between the refrigerant expanded by the expansion valve and outdoor air; a high-tension pressure sensor configured to detect the temperature of the refrigerant to be condensed in the water heat exchanger; a discharged water temperature sensor configured to detect the temperature of water on which heat exchange has been performed in the water heat exchanger; and a control unit including a controller comprising circuitry configured to: determine a target condensation temperature of the refrigerant based on a detection result of the discharged water temperature sensor, compare the target condensation temperature with the current condensation temperature detected by the high-tension pressure sensor, and control the degree of opening of the expansion valve based on the comparison result.

A system for space heating or cooling a heated space includes a heat pump including a refrigeration circuit for transferring heat between a heat source and a heat load for heating and cooling operations. A controller controls the heat pump to perform the heating and cooling operations. A user interface receives user inputs, wherein the user inputs include an indication of discomfort based on temperature. The controller creates a profile for a minimum comfortable temperature level and a maximum comfortable temperature level, and the controller controls the heat pump to perform the heating and cooling operations in accordance with the profiles for the minimum and maximum comfortable temperature levels. The controller may generate an optimized heat demand plan in accordance with predictions of outdoor and indoor temperature, cost, and demand. The plan is optimized to cost-effectively maintain the temperature of the heated space within the comfortable temperature range defined by the profiles.

An apparatus comprises a sensor circuit configured to detect activation of at least one circulator arranged to circulate liquid from a boiler through at least one circulation loop and back to the boiler. An analog up/down timer circuit has an input coupled to an output of the sensor circuit and generates a variable threshold signal that varies as a function of an activation time of the at least one circulator. A burner control circuit receives the variable threshold signal from the analog up/down timer circuit and generates an ignition control signal based at least in part on comparison of a temperature sensor signal of the boiler with the variable threshold signal. An ignition driver receives the ignition control signal from the burner control circuit and generates an ignition signal for a burner configured to burn fuel to heat the liquid in the boiler based at least in part on the ignition control signal.

An apparatus comprises a sensor circuit configured to detect activation of at least one circulator arranged to circulate liquid from a boiler through at least one circulation loop and back to the boiler. An analog up/down timer circuit has an input coupled to an output of the sensor circuit and generates a variable threshold signal that varies as a function of an activation time of the at least one circulator. A burner control circuit receives the variable threshold signal from the analog up/down timer circuit and generates an ignition control signal based at least in part on comparison of a temperature sensor signal of the boiler with the variable threshold signal. An ignition driver receives the ignition control signal from the burner control circuit and generates an ignition signal for a burner configured to burn fuel to heat the liquid in the boiler based at least in part on the ignition control signal.

A thermal storage heat pump system transfers heat to a passenger compartment of a vehicle from at least one of a thermal storage device and ambient air. Heat from the thermal storage device is absorbed by a first coolant flowing through it, and is transferred to a refrigerant via a first heat exchanger. The heat is then transferred from the refrigerant to a second coolant via a second heat exchanger, and then from the second coolant to air flowing into the passenger compartment via a heater core. Heat from ambient air is absorbed by the refrigerant via a third heat exchanger. The heat source is determined by at least one of the thermal storage device temperature, ambient air temperature, and ambient air humidity. At start-up of the vehicle, heat transfer to the refrigerant and to the second coolant is controlled based on low-side and high-side pressure measurements of the refrigerant.

A method for operating a heat pump water heater appliance positioned with a building is provided. The method includes receiving a measurement of ambient temperature about the building via a network and also getting a measurement of ambient temperature about the heat pump water heater appliance within the building. The method further includes heating water within the heat pump water heater appliance with only a sealed system of the heat pump water heater appliance or with only a secondary heating element of the heat pump water heater appliance based upon the measurement of ambient temperature about the building and the measurement of ambient temperature about the heat pump water heater appliance within the building.

An air conditioning system includes a heat pump section performing indoor air-warming by using a vapor-compression refrigeration cycle, a separate heat source section performing indoor air-warming by using a heat source separate from the heat pump section, and a control unit configured to control actions of the heat pump section and the separate heat source section. When an operation is switched from a separate heat source air-warming operation to a heat pump air-warming operation, the control unit starts the heat pump air-warming operation while the separate heat source air-warming operation is continued, and after an overlapping air-warming ending condition is met, the control unit ends the separate heat source air-warming operation. The overlapping air-warming ending condition is that a temperature difference resulting from subtracting a target indoor temperature from an indoor temperature is equal to or greater than an overlapping air-warming ending air temperature difference.