Heat pump system (100) comprising at least one heat medium circuit (210,220,230,240,250,310,320,410,420,430,440,450,460) in turn comprising a compressor (211), an expansion valve (232,242), at least two different primary heat sources or sinks selected from outdoor air, a water body, the ground or exhaust air, at least one of two different secondary heat sources or sinks selected from indoors air, pool water and tap water, a respective temperature sensor (412,432) at each of said primary heat sources or sinks, a valve means (421,431,451) for selectively directing the primary-side heat medium to at least one of said primary heat exchanging means, and a control means (500). The invention is characterised in that, in a secondary-side heating operating mode, the temperature of said primary heat sources or sinks is measured, and in that the primary-side heat medium is directed only to available primary heat exchanging means associated with the heat sources or sinks with the highest temperature. The invention also relates to a method.

A system for collecting solar energy to be stored and distributed in a multi-unit building to be used for heat and electricity, comprising one or more solar energy collectors, one or more sunlight concentrating mirrors, photovoltaic panels, a heat mass storage area, and thermos siphoning to distribute heat energy throughout the building in conjunction with radiant heating technology.

A hybrid heating system having a heat recovery apparatus in fluid communication with a heat pump and a furnace is provided. The apparatus recovers heat from flue gas discharged from the furnace and transfers the recovered heat to a stream of refrigerant in the heat pump. The apparatus includes a shell disposed in fluid communication with the furnace and tubes disposed in fluid communication with the shell and the heat pump. The system includes valves for regulating access between the apparatus and the stream of the refrigerant in the heat pump, and a control unit in communication with the valves to regulate access between the apparatus and the heat pump during a heating mode based on operating parameters of the system.

A method and arrangement for conditioning a building space of a building includes extracting heat energy from the building space to heat pump working fluid with a primary heat exchange connection of a heat pump and releasing heat energy from the heat pump working fluid with a secondary heat exchange connection of the heat pump to geothermal working fluid of a geothermal heat exchanger. The method further includes releasing heat energy from the geothermal working fluid to ground at lower part of the ground hole having depth at least 300 meters, producing solar energy with a solar energy apparatus provided to the building, and supplying the solar energy to the heat pump or to the geothermal heat exchanger.

Systems and methods utilize 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 utilize 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 utilize 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.

A heating system for heating a fluid received at an inlet, the system including a first heating device disposed in a first heated line branched from the inlet, wherein a first flow of the fluid through the first heated line is configured to be modulated by a first valve; a second heating device disposed in a second heated line branched from the inlet, wherein a second flow of the fluid through the second heated line is configured to be modulated by a second valve; and a bypass line and a third valve disposed in the bypass line, wherein a flow through the bypass line is configured to be modulated by the third valve, wherein the first and second heating devices and the first, second and third valve are configured to cooperate to heat the fluid at an outlet received from the first and second heated line and the bypass line.

Provided is an indoor unit for a heat pump use apparatus, the indoor unit being a part of the heat pump use apparatus including a refrigerant circuit configured to circulate refrigerant, a heat medium circuit configured to allow a heat medium to flow through the heat medium circuit, and a heat exchanger configured to exchange heat between the refrigerant and the heat medium. The indoor unit is connectable to an outdoor unit accommodating the refrigerant circuit and the heat exchanger. The indoor unit accommodates a part of the heat medium circuit. The indoor unit includes a pressure protection device connected to the heat medium circuit, and an on-off device provided to be interposed between the heat medium circuit and the pressure protection device.

A method includes selecting a state model control, as an operational state of the heater, from among a plurality of state model controls, measuring an electrical characteristic of the heater, where the electrical characteristic includes at least one of an electric current and a voltage, and controlling power to the heater based on the selected operational state and based on the measured electrical characteristic.