Abstract: A first heat exchanger, a desiccant block, and a second heat exchanger are arranged in series. In a dehumidifying operation, a first operation mode and a second operation mode are alternately repeated. In the first operation mode, the first heat exchanger is operated as a condensor or a radiator and the second heat exchanger is operated as an evaporator. In the second operation mode, the first heat exchanger is operated as the evaporator and the second heat exchanger is operated as the condensor or radiator. A pressure reducing amount in the first operation mode is controlled to be smaller than in the second operation mode so that a degree of superheat in the evaporator (second heat exchanger in the first operation mode, first heat exchanger in the second operation mode) in each of the first operation mode and the second operation mode is appropriately controlled to increase a dehumidifying amount.

Abstract: A first heat exchanger, a desiccant block, and a second heat exchanger are arranged in series. Further, in a dehumidifying operation, a first operation mode and a second operation mode are alternately repeated. In the first operation mode, the first heat exchanger is operated as a condensor or a radiator and the second heat exchanger is operated as an evaporator. In the second operation mode, the first heat exchanger is operated as the evaporator and the second heat exchanger is operated as the condensor or the radiator. Further, an interval between fin surfaces of a plurality of fins in each of the first heat exchanger and the second heat exchanger is set to 1.5 mm to 3.0 mm so that drainage performance for dew condensation on the fin surfaces is enhanced to reduce an amount of the dew condensation stagnating on the fin surfaces and increase a dehumidifying amount.

Abstract: On the basis of a detection result obtained by a pre-presence-in-room environment detection means, an air-conditioning apparatus A changes a presence-in-room start set temperature Ts serving as a target temperature at the start time of a precooling operation or a preheating operation and at the presence-in-room start scheduled time of the user.

Abstract: An air-conditioning apparatus includes refrigerant systems that each include an outdoor unit and indoor units and that air-condition a single room, and circulators for making a temperature distribution in the room uniform. The air-conditioning apparatus determines a load on each of the two refrigerant systems in operation, and, if it is determined that improvement of operating efficiency is possible on the basis of the determination result, performs a system-selective operation in which operation of one of the refrigerant systems determined to be under a low load is stopped and the other refrigerant system determined to be under a high load is selectively performed, and causes the circulators to transport blown air blown from the indoor units of the refrigerant system determined to be under a high load to an air-conditioned zone of the refrigerant system determined to be under a low load.

Abstract: Provided are a refrigeration cycle that is formed by connecting a compressor, a condenser, expansion means, and an evaporator and that performs cooling operation; an evaporator heating device that heats the evaporator; a drain pan that receives drain-water from the evaporator and drains the drain-water; a drain-pan heating device that heats the drain pan; frost detecting means including a light-emitting element that emits light to the evaporator and a light-receiving element that receives reflected light from the evaporator and outputs a voltage according to the reflected light; and a control device that controls on-off operation of the evaporator heating device and the drain-pan heating device. The control device determines a frosting condition on the evaporator from an output of the frost detecting means and individually controls the evaporator heating device and the drain-pan heating device in accordance with the determination result.

Abstract: A mode selection unit selects a continuous operation mode when a dehumidifying operation is started. When an indoor temperature is less than or equal to a set first temperature threshold and indoor humidity is greater than a set humidity threshold in the continuous operation mode, the mode selection unit selects an intermittent operation mode. When the indoor temperature is less than or equal to a set second temperature threshold that is greater than the first temperature threshold and the indoor humidity is less than or equal to the set humidity threshold in the intermittent operation mode, the mode selection unit selects an operation stop mode.

Abstract: A refrigeration cycle apparatus Including a refrigerant circuit configured to circulate refrigerant to a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger, the compressor being connected to the indoor heat exchanger by a gas extension pipe, the expansion valve being connected to the outdoor heat exchanger by a liquid extension pipe; pressure sensors and temperature sensors to detect an operating state amount of the refrigerant circuit; and a controller to execute refrigerant-leakage detection operation of detecting refrigerant leakage by calculating a refrigerant amount in the refrigerant circuit based on the operating state amount detected by the pressure sensors and the temperature sensors, and comparing the calculated refrigerant amount with a reference refrigerant amount. The controller controls a quality of the refrigerant at an outlet of the liquid extension pipe to be in a range from 0.1 to 0.7 in the refrigerant-leakage detection operation.

Abstract: A controller of an air-conditioning apparatus includes an operation control unit that controls operation of a compressor of a heat source unit based on target indoor temperatures of rooms, an unoccupied room detecting unit that detects an unoccupied room where no person is present among the rooms, and a correction amount setting unit that sets a temperature correction amount for correcting the target indoor temperature in a room controller of the unoccupied room detected by the unoccupied room detecting unit to reduce an air conditioning load for the unoccupied room. After the target indoor temperature is corrected by using the temperature correction amount in the room controller, when the operation capacity of the compressor controlled by the operation control unit is smaller than or equal to a preset operation capacity, the correction amount setting unit resets the temperature correction amount to be decreased by an adjustment amount.

Abstract: A refrigerating apparatus includes: a refrigerating circuit in which a refrigerant that is discharged from a compressor is conveyed under pressure sequentially to a first flow rate controlling apparatus, a heat storing tank, a condenser, a first decompressing apparatus, and an evaporator, and is recycled to the compressor; a defrosting circuit in which the refrigerant that is discharged from the compressor is conveyed under pressure sequentially to the first flow rate controlling apparatus, the heat storing tank, the first decompressing apparatus, and the evaporator, and is recycled to the compressor; and a flow channel switching apparatus that connects an outlet side of the heat storing tank to an inlet side of the condenser or to an inlet side of the first decompressing apparatus to form the refrigerating circuit or the defrosting circuit.

Abstract: In an air-conditioning system, during precooling or preheating control, a setting temperature is controlled such that a first temperature difference between the setting temperature and an indoor temperature is not less than a temperature difference at which a compressor performs operation, and the setting temperature is controlled to be changed to a target temperature when a second temperature difference between the indoor temperature and the target temperature is less than the first temperature difference. Since the compressor can be operated in the range from a low capacity to a medium capacity, operation efficiency of the air-conditioning apparatus can be increased, and the energy-saving operation with less power consumption can be realized. Since the operation capacity of the compressor can be readily suppressed with adjustment of the setting temperature, control is facilitated and the precooling control can be incorporated in various types of air-conditioning apparatuses.

Abstract: An air-conditioning system is configured to determine an evaporating temperature control range of a first refrigerant circuit on the basis of the temperature of outdoor air, control an evaporating temperature of the first refrigerant circuit to a target evaporating temperature determined within the evaporating temperature control range of the first refrigerant circuit, determine an evaporating temperature control range of a second refrigerant circuit on the basis of the humidity of the outdoor air, and control an evaporating temperature of the second refrigerant circuit to a target evaporating temperature determined within the evaporating temperature control range of the second refrigerant circuit.

Abstract: A heat pump heating and hot-water system includes a water heating heat exchanger for heating water by heat exchange with a heating medium heated by a heat pump unit, an indoor heating unit, a heating circulation circuit for selectively pumping the heating medium to either of the water heating heat exchanger and the indoor heating unit using a heating medium pump, and a hot-water accumulating circuit that sends water in a hot-water storage tank to the water heating heat exchanger and returns water having passed through the water heating heat exchanger to the hot-water storage tank using a water pump. The volumetric flow rate of the heating medium pumped to the water heating heat exchanger by the heating medium pump is higher than or equal to the volumetric flow rate of the water pumped to the water heating heat exchanger by the water pump.

Abstract: Provided is an oil level detection device to be mounted on a refrigerating and air-conditioning apparatus, the oil level detection device being configured to detect an oil level of oil accumulated inside a compressor forming the refrigerating and air-conditioning apparatus. The oil level detection device includes an oil level detection unit installed on an outer surface of the compressor and configured to detect a temperature of an installation position, a sensor output unit configured to output, to the refrigerating and air-conditioning apparatus, a signal for changing an operation state of the refrigerating and air-conditioning apparatus, and a determination unit configured to determine depletion of the oil accumulated inside the compressor based on measurement values obtained by the oil level detection unit at least after an output of the signal to be output from the sensor output unit.

Abstract: A liquid level detection device at least includes a heating member that heats a container, a temperature measurement element disposed on a side of the heating member opposite to the container, a thermal conductor disposed between the heating member and the container, an elastic body that presses the heating member with a certain amount of force, a terminals for supplying power to the heating member, a fixture that covers the heating member, the temperature measurement element, the thermal conductor, the elastic body and the terminals and mount those on the container, wherein the heating member does not come into contact with the terminals when at least one of the thermal conductor and the fixture is inappropriately mounted on a container.

Abstract: Maximum evaporating temperature setting values and minimum evaporating temperature setting values in an indoor heat exchanger and a ventilator cooler are determined in accordance with outdoor air temperature and humidity, evaporating temperature setting values in the indoor heat exchanger and the ventilator cooler are set to be between the respective maximum evaporating temperature setting values and the respective minimum evaporating temperature setting values, and evaporating temperatures in the indoor heat exchanger and the ventilator cooler are controlled so as to be the respective evaporating temperature setting values.

Abstract: A refrigeration cycle apparatus includes low-pressure side pressure detecting means for detecting the pressure of a refrigerant being sucked by a compressor, suction refrigerant temperature detecting means for detecting the temperature of the refrigerant being sucked by the compressor, frequency detecting means for detecting the operation frequency of the compressor, cooling target fluid inflow temperature detecting means for detecting the temperature of a cooling target fluid flowing in an evaporator, cooling target fluid outflow temperature detecting means for detecting the temperature of the cooling target fluid flowing out of the evaporator, and flow rate calculating means (measuring unit, computing unit, and storage unit) for calculating the absolute quantity of the flow rate of the cooling target fluid flowing in the evaporator using a value detected by each detecting means.

Abstract: A first heat exchanger, a desiccant block, and a second heat exchanger are arranged in series. In a dehumidification operation, a first operation mode in which the first heat exchanger acts as a condenser or a radiator and the second heat exchanger acts as an evaporator and a second operation mode in which the first heat exchanger acts as an evaporator and the second heat exchanger acts as a condenser or a radiator are alternately repeated.

Abstract: A dehumidifying apparatus controls the amount of refrigerant flowing into a third heat exchanger serving as a condenser, so as to secure the amount of heat required for defrosting.

Abstract: An air-conditioning apparatus includes refrigerant systems that each include an outdoor unit and indoor units and that air-condition a single room, and circulators for making a temperature distribution in the room uniform. The air-conditioning apparatus determines a load on each of the two refrigerant systems in operation, and, if it is determined that improvement of operating efficiency is possible on the basis of the determination result, performs a system-selective operation in which operation of one of the refrigerant systems determined to be under a low load is stopped and the other refrigerant system determined to be under a high load is selectively performed, and causes the circulators to transport blown air blown from the indoor units of the refrigerant system determined to be under a high load to an air-conditioned zone of the refrigerant system determined to be under a low load.

Abstract: A refrigeration and air-conditioning apparatus rapidly varies the pressure or the temperature inside a liquid reserve container to identify a liquid level position inside the liquid reserve container on the basis of the surface temperature of the liquid reserve container.