An apparatus for heating water has a tank for storing water and an air conditioning system that defines a refrigerant flow path through which refrigerant flows. The refrigerant flow path passes through the heat exchanger so that refrigerant heat is contributed to the tank. A control system controls operation of the water heating apparatus.

The present invention provides a heat pump system and a wastewater tank. The heat pump system comprises: a main circuit connecting a compressor, a first heat exchanger, a throttling element, and a refrigerant pipeline of a second heat exchanger; a wastewater tank for receiving and storing domestic wastewater; a wastewater heat recovery circuit connecting a driving device, a first heat exchange unit, and a defrosting pipeline of the second heat exchanger, wherein the second heat exchanger is a three-medium fluid heat exchanger, the defrosting pipeline and the refrigerant pipeline are thermally coupled with each other, and the first heat exchange unit is thermally coupled with the wastewater tank; wherein, the heat pump system has a fast defrosting mode in which the wastewater heat recovery circuit transports residual heat from wastewater in the wastewater tank to the second heat exchanger to accelerate defrosting.

One embodiment provides a cascade phase change material (PCM) natural refrigerant heat pump system that includes multiple heat pumps. A heat exchanger is connected to the multiple heat pumps. A thermal battery bank including multiple PCM battery cells is connected to the heat exchanger in a closed loop. A circulator pump is connected to the heat exchanger and the multiple PCM battery cells.

One embodiment provides a cascade phase change material (PCM) natural refrigerant heat pump system that includes multiple heat pumps. A heat exchanger is connected to the multiple heat pumps. A thermal battery bank including multiple PCM battery cells is connected to the heat exchanger in a closed loop. A circulator pump is connected to the heat exchanger and the multiple PCM battery cells.

An apparatus for heating water has a tank for storing water and an air conditioning system that defines a refrigerant flow path through which refrigerant flows. The refrigerant flow path passes through the heat exchanger so that refrigerant heat is contributed to the tank. A control system controls operation of the water heating apparatus.

An apparatus for heating water has a tank for storing water and an air conditioning system that defines a refrigerant flow path through which refrigerant flows. The refrigerant flow path passes through the heat exchanger so that refrigerant heat is contributed to the tank. A control system controls operation of the water heating apparatus.

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.

A refrigeration cycle apparatus simultaneously performs a cooling operation mode in which a refrigerant from a compressor is caused to flow to an indoor heat exchanger of an indoor unit having a cooling load, and a hot water supply operation mode in which a refrigerant from the compressor is caused to flow to a water heat exchanger of a hot water supply unit having a hot water supply demand. An operation control part switches the control mode of the simultaneous cooling and heating and hot water supply operation mode between a cooling-prioritized mode and a hot-water-supply-prioritized mode according to the relationship between the cooling load and the hot water supply load.

An apparatus for heating water has a tank for storing water and an air conditioning system that defines a refrigerant flow path through which refrigerant flows. The refrigerant flow path passes through the heat exchanger so that refrigerant heat is contributed to the tank. A control system controls operation of the water heating apparatus.

A water heater appliance includes a tank and a heated water conduit extending from the tank. A mixing valve is coupled to the heated water conduit, and a heat trap is mounted to the heated water conduit upstream of the mixing valve. The heat trap includes a membrane disposed within the heated water conduit. The membrane of the heat trap may assist with obstructing recirculation of heated water from the tank into the heated water conduit.