Heat pump system (100) comprising a heat medium circuit (210,220,230,240,250,310,320,410,420,430,440,450,460) in turn comprising at least three heat exchanging means (314,315,315,422,433,452) between the heat medium and a respective heat source or sink selected from outdoor air, a water body, the ground, indoor air, pool water or tap water, a valve means (311,312,313,421,431,451) arranged to selectively direct the heat medium to at least two of said heat exchanging means, and a control means (500). The invention is characterized in that the heat pump system comprises temperature sensors (314a,314b;315a,315b;316a,316b;423,424,425;432,434,435) both upstream and downstream of at least one of said heat exchanging means, in that the system determines, based upon temperature measurement values comprising at least one value read from said sensors, to what heat exchanging means the heat medium is to be directed, and in that when heat medium is not directed to a certain heat exchanging means a measured temperature value is read upstream and downstream of the certain heat exchanging means, and in that an alert is set off in case the values differ by more than a predetermined value. The invention also relates to a method.

A heat pump water heater has a tank, a heat source, and a heat pump system. The heat pump system has a refrigerant path, at least a portion of which is in thermal communication with the water tank volume so that heat transfers from refrigerant to the water tank volume. A fan causes air to flow through a housing, and another portion of the refrigerant path includes an evaporator in the housing. The fan is within the housing and may further be within a second housing. The first housing may comprise a baffle to direct air flow. The fan may be a variable speed fan in communication with a controller, so that the controller controls the fan speed depending on a temperature of the refrigerant.

A heating system (100), a controller (110) for a heating system and a method of controlling a heating system (100) suitable for responding to grid stress events are disclosed. A heating system (100) comprises a tank (104) for holding water; a heat pump (102) arranged to provide heat to the tank (104); an electric heating element (108) disposed in the tank for heating water; and, a controller (110) configured to: control electric power from an electric power grid to the heat pump (102) and the electric heating element (108); detect a grid stress event; determine a heat pump energy penalty for providing heat in response to the grid stress event under a present operating condition; and, vary, in dependence on the determined heat pump energy penalty, a power provided to the electric heating element (108).

A heating system (100), a controller (110) for a heating system and a method of controlling a heating system (100) suitable for responding to grid stress events are disclosed. A heating system (100) comprises a tank (104) for holding water; a heat pump (102) arranged to provide heat to the tank (104); an electric heating element (108) disposed in the tank for heating water; and, a controller (110) configured to: control electric power from an electric power grid to the heat pump (102) and the electric heating element (108); detect a grid stress event; determine a heat pump energy penalty for providing heat in response to the grid stress event under a present operating condition; and, vary, in dependence on the determined heat pump energy penalty, a power provided to the electric heating element (108).

A water heater appliance, including methods of operation, is provided herein. The water heater appliance may include a casing, a tank, an inlet conduit, an electric heating system, and a controller coupled to an auxiliary power generator. The tank may be disposed within the casing and define an inlet and an outlet. The inlet conduit may be mounted to the tank at the inlet of the tank. The controller may be operably coupled to the electric heating system and configured to initiate a heating cycle. The heating cycle may include identifying a daily peak auxiliary power period, determining a contemporary voltage reading at the water heater appliance, predicting an occurrence of the daily peak auxiliary power period from the auxiliary power generator, and heating water within the water heater at the predicted occurrence of the daily peak auxiliary power period.

An air conditioning system includes a heat pump having a refrigerant radiator, a gas furnace unit having a heating section to heat passing air, a blower generating air flow through the radiator and the heating section, and a controller controlling operation of the heat pump unit, the gas furnace unit, and the blower. The controller has a first operating mode in which the gas furnace unit operates alone as a heat source unit, a second operating mode in which the heat pump unit operates alone as a heat source unit, and a third operating mode in which the gas furnace unit and the heat pump unit operate at the same time as a heat source unit. The controller is configured to select the operating modes based on a parameter relating to outside air temperature that is the temperature of outside air.

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 heat pump water heater has a tank, a heat source, and a heat pump system. The heat pump system has a refrigerant path, at least a portion of which is in thermal communication with the water tank volume so that heat transfers from refrigerant to the water tank volume. A fan causes air to flow through a housing, and another portion of the refrigerant path includes an evaporator in the housing. The fan is within the housing and may further be within a second housing. The first housing may comprise a baffle to direct air flow. The fan may be a variable speed fan in communication with a controller, so that the controller controls the fan speed depending on a temperature of the refrigerant.

A method of and system for heating and/or cooling a fluid, the method comprising moving the fluid through a secondary side of a heat exchanger and controlling the temperature of a primary side of the heat exchanger such that the temperature of the primary side of the heat exchanger is maintained substantially at a determined temperature interval from a reference temperature which is a function of at least one of: a temperature of an inlet to the secondary side and a temperature of an outlet of the secondary side.

When a heating operation mode using a heating unit is specified and when a hot water supply request using the hot water in a hot water storage tank does not occur, an air conditioning apparatus transmits a first selection signal for selecting the heating unit to a three-way valve. When the heating operation mode is specified and when the hot water supply request occurs, the air conditioning apparatus transmits, to the three-way valve, a second selection signal for changing a destination of circulation of secondary refrigerant from the heating unit to a coil heat exchanger, and transmits an operation start signal to a refrigerant indoor unit.