In an air-conditioning apparatus including a refrigerant circulating circuit A and a heat medium circulating circuit B that performs passing of heat to and from the refrigerant circulating circuit A, the heat medium circulating circuit is a closed circuit, the maximum pump head Pp of a pump of the heat medium circulating circuit is 150 kPa or more, and a pressure near at least a suction side of the pump is set to a charged pressure that is maintained equal to or higher than the atmospheric pressure during operation of the pump.

A dedicated outdoor air system (DOAS) includes an outdoor unit providing a temperature at a set dry bulb temperature and dew point temperature in a wide variety of outdoor air conditions. The DOAS monitors and modulates suction pressure and head pressure in order to maintain a dew point temperature of 45° F. for supplied air. Furthermore, the DOAS includes a hot gas reheat coil, allowing the system to heat the air to 73° F. before supplying the air to a space, even where outdoor air temperature is lower than 73° F. In one embodiment, the DOAS includes an energy recovery ventilator (ERV) in order to precondition the air to decrease the amount of energy needed to operate the DOAS in some conditions.

The utility model relates to environment-friendly energy-saving parallel-connection temperature-humidity regulation and control equipment, which includes a compressor unit, a condenser, an evaporation coil and a secondary heat exchange coil which are connected with one another through pipelines, wherein the evaporation coil and the secondary heat exchange coil are disposed in a temperature-humidity controlled region, and the temperature-humidity controlled region is further internally provided with a temperature-humidity transmitter; and further includes a bypass electromagnetic valve and an intelligent control cabinet

In an air-conditioning apparatus including a plurality of indoor units connected to a heat medium converter and a plurality of remote controllers respectively provided for the indoor units, the remote controllers each include a temperature sensor that detect a temperature of a corresponding space to be air-conditioned, and are each configured to communicate with a heat medium converter controller of the heat medium converter and an indoor unit controller of the corresponding indoor unit, transmit an instruction to start and stop an operation and data related to rotation speed of an indoor air-sending device to the corresponding indoor unit controller, and transmit the instruction to start and stop the operation, and a target temperature and a temperature detected by the temperature sensor or a difference therebetween, to the heat medium converter controller.

An integrated device in an HVAC system is configured to modify an environmental condition of a building. The device includes a valve configured to regulate the flow of fluid through a conduit, an actuator comprising a motor and a drive device, and a communications mechanism. The communications mechanism is configured to receive a flow rate setpoint from an external control device of an outer control loop. The device further includes a processing circuit. The processing circuit is configured to determine an actuator position setpoint using a cascaded feedback control mechanism based on the flow rate setpoint and a flow rate measurement from a flow rate sensor of an inner control loop. The valve, the actuator, the communications mechanism, and the processing circuit are located within a common integrated device chassis.

An air conditioner includes an outdoor unit, a plurality of indoor units, a plurality of expansion valves which are provided upstream of indoor heat exchangers, a plurality of on-off valves which are provided upstream of the expansion valves, and control unit wherein when the indoor units include a stopping indoor unit and an operating indoor unit currently operating, and when a stopping of the stopping unit is due to thermostat-off operation, the control unit performs a procedure to stop the stopping unit, the procedure including closing an on-off valve that corresponds to the stopping unit and driving an indoor fan in the stopping unit until pressure in a part between the on-off valve and an expansion valve that corresponds to the stopping unit and pressure in a part downstream of the first expansion valve are equalized, fully opening the expansion valve, and stopping the indoor fan.

A controller of an HVAC system is communicatively coupled to a liquid-side sensor and a shutoff switch. The controller stores measurements of a liquid-side property over an initial period of time. The controller detects that the shutoff switch is tripped at a first time stamp corresponding to an end of the initial period of time. The controller accesses the measurements of the liquid-side property. The controller determines, based on the measurements of the liquid-side property, that the liquid-side property has a decreasing trend. In response to determining that the liquid-side property has the decreasing trend, a malfunction of a blower of the system is determined to have caused the shutoff switch to trip.

A process and apparatus for monitoring and/or controlling at least one air conditioning and/or heating plant (1) including a delivery line (3), a return line (4) and service lines (5) hydraulically interposed between the delivery line (3) and the return line (4), each service line (5) comprising at least one thermal exchange unit (7). The process detects a value (φ) of the flow rate of the carrier fluid traversing the thermal exchange unit (7), and determines a temperature difference (ΔT) between the temperature (Tt1) of the carrier fluid, at the first section (5a), detected at a first instant (t1), and the temperature (Tt2) of the carrier fluid, at the second section (5b), detected at a second instant (t2).

An intermediate unit includes a liquid-side pipe, a first valve, and a refrigerant pressure sensor. The liquid-side pipe is connected to a liquid connection pipe connecting a heat source unit and a utilization unit together. A controller of the intermediate unit adjusts the opening degree of the first valve based on a value measured by the refrigerant pressure sensor. The pressure of a refrigerant to be sent through the liquid connection pipe from the intermediate unit to the utilization unit is adjusted by the first valve.

One aspect presents a controller that comprises a control board, a microprocessor located on and electrically coupled to the control board, and a memory coupled to the microprocessor and located on and electrically coupled to the control board. The controller is configured to receive an operating parameter signal and recalculate a first maximum heating % demand to a second maximum heating % demand that is greater than the first maximum heating % demand, when a value of the operating parameter signal exceeds a predetermined value, and operate the HP system based on the second maximum heating % demand.