A heat-pump air-conditioning hot-water supply device includes a first refrigerant passage connecting a compressor and a decompressor, a second refrigerant passage branching from between the compressor and a first solenoid valve and connecting a second solenoid valve, a hot-water supply heat exchanger, and the decompressor, a pressure sensor configured to measure discharge pressure of the compressor, and a control device configured to adjust an operational frequency of the compressor and adjust an opening degree of a valve of the decompressor. The control device is configured to calculate a condensing temperature from the discharge pressure, and perform operation in one of an air conditioning prioritized mode in which a preset operational frequency of the compressor is changed, and an energy saving prioritized mode in which the opening degree of the valve of the decompressor is changed, when the condensing temperature is not lower than a set condensing temperature.

An air heating and cooling system includes (1) a heat pump, illustratively devoid of auxiliary electric resistance type air heating structure, operative to provide refrigerant-based heating or cooling of air being delivered to a conditioned space, (2) a fuel-fired modular blower selectively operable to generate combustion heat, and (3) a control system associated with the heat pump and the modular blower. The control system has a heat pump thermostat electrically connected to a modular blower control and operative to transmit to the modular blower a first signal indicative of heating operation of the heat pump, and a second signal indicative of a need for alternative heat during a heating demand cycle. The modular blower is operative, in response to receiving both signals, to provide combustion-based air heating in place of refrigerant-based heat pump air heating.

A heat-pump circuit may include an indoor heat exchanger, an outdoor heat exchanger, a compressor adapted to circulate a working fluid between the indoor and outdoor heat exchangers, and an expansion device disposed between the indoor and outdoor heat exchangers. A monitor for the heat-pump system may include a return-air temperature sensor, a supply-air temperature sensor, and a processor. The return-air temperature sensor may be adapted to measure a first air temperature of air upstream of the indoor heat exchanger. The supply-air temperature sensor may be adapted to measure a second air temperature of air downstream of the indoor heat exchanger. The processor may be in communication with the return-air temperature sensor and the supply-air temperature sensor. The processor may be programmed to determine a working-fluid-charge condition of the heat-pump system based on the first and second air temperatures.

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 sinksis measured, and in that the primary-side heat medium is directed only to the primary heat exchanging means associated with the heat sources or sinks with the highest temperature. The invention also relates to a method.

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, indoorair, 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 onevalue 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 heatexchanging 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.

The invention relates to an HVAC apparatus, method, and system. Aspects of the invention include a supplemental heat source with an air handler unit for a conventional forced air heating and cooling system. The supplemental heat source in one example is a hydronic subsystem. It can be used alone or to supplement the forced air subsystem. Another aspect of the invention includes an air handling subsystem that has a housing that can be highly flexible in configuration and installation. The housing can support internal components, including a hydronic or other supplemental heat source with the forced air components. At least two sides of the housing can be configured for access for maintenance and repair. A control system can be designed to eliminate need for defrost cycle for forced air refrigeration-type subsystem and/or for better maintenance for comfort in the air conditioned space.

A heat-pump circuit may include an indoor heat exchanger, an outdoor heat exchanger, a compressor adapted to circulate a working fluid between the indoor and outdoor heat exchangers, and an expansion device disposed between the indoor and outdoor heat exchangers. A monitor for the heat-pump system may include a return-air temperature sensor, a supply-air temperature sensor, and a processor. The return-air temperature sensor may be adapted to measure a first air temperature of air upstream of the indoor heat exchanger. The supply-air temperature sensor may be adapted to measure a second air temperature of air downstream of the indoor heat exchanger. The processor may be in communication with the return-air temperature sensor and the supply-air temperature sensor. The processor may be programmed to determine a working-fluid-charge condition of the heat-pump system based on the first and second air temperatures.

A system for conditioning air circulated from an interior of a building includes a refrigerant path, an air-cooled condenser in the refrigerant path, a water-cooled condenser in the refrigerant path that transfers heat from refrigerant in the refrigerant path to the building water, an evaporator in the refrigerant path, and a control system. The control system moves the system between operation of the air-cooled condenser and the water-cooled condenser based upon predetermined system conditions.

An air-conditioning apparatus according to the present invention includes at least indoor heat exchangers. In response to a request to increase heat exchange performance from the indoor heat exchanger, the air-conditioning apparatus decreases a heat exchange capacity of an outdoor heat exchanger and controls an opening degree of an expansion valve corresponding to the indoor heat exchanger to decrease a flow rate of a refrigerant that flows through the indoor heat exchanger.

A system for conditioning air circulated from an interior of a building includes a refrigerant path, an air-cooled condenser in the refrigerant path, a water-cooled condenser in the refrigerant path that transfers heat from refrigerant in the refrigerant path to the building water, an evaporator in the refrigerant path, and a control system. The control system moves the system between operation of the air-cooled condenser and the water-cooled condenser based upon predetermined system conditions.