An HVAC system includes a single compressor, a pair of condensers, a reheat heat exchanger, an evaporator, and an expansion device. Within the system, the refrigerant exiting the compressor is separated into two portions. In the cooling mode, the first and second portions of the refrigerant are directed from the compressor through the two condensers in parallel. In the reheat mode, the first portion of the refrigerant is directed through the first condenser, while the second portion of the refrigerant is directed through the reheat heat exchanger. The system also may include a head pressure control device that is designed to maintain the compressor discharge pressure within a desired range by adjusting the condenser fan speed.

A compressor driving device includes a three-phase alternating current power supply input end, a relay module, a rectifier circuit, and a driving control circuit which are sequentially connected; the rectifier circuit is used for converting connected alternating current into direct current and then outputting the direct current to a direct current bus; the driving control circuit is used for converting the direct current output by the direct current bus into compressor driving power; a pressure switch is used for measuring the pressure value in a refrigerating system, and when the measured pressure value is larger than a preset pressure threshold, disconnecting the power supply circuit of the relay module; the driving control circuit is also used for detecting the on-off state of the pressure switch and controlling the compressor to stop working when the pressure switch is switched off.

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.

An air-conditioning apparatus includes a refrigerant circuit in which a compressor, a refrigerant flow switching device, a heat source side heat exchanger, an expansion device, a heat medium heat exchanger, and an accumulator are connected, a heat medium circuit in which a pump, the heat medium heat exchanger, a heat medium flow control device, and a load side heat exchanger are connected, at least one or more bypass pipes provided in the refrigerant circuit so that the refrigerant discharged from the compressor bypasses at least either one of the heat source side heat exchanger and the heat medium heat exchanger, a bypass opening and closing device provided at the bypass pipe, and a controller configured to control the bypass opening and closing device to carry out a start-up control function of causing low-pressure gas refrigerant with a high degree of superheat to flow into the accumulator.

An air conditioner and control method for reducing power consumption by controlling pressure or temperature of a refrigerant. The air conditioner includes a compressor compressing a refrigerant and discharging a high pressure refrigerant gas; an outdoor heat exchanger in which the high pressure refrigerant gas is changed to a refrigerant fluid; an outdoor fan to blow outdoor air to the outdoor heat exchanger; a decompressor decompressing the refrigerant fluid into a low pressure state; an indoor heat exchanger changing the decompressed low pressure refrigerant fluid to a refrigerant gas; and a controller configured to control pressure or temperature of the refrigerant based on an operation condition including at least two of a first condition determined based on an installation environment, a second condition determined based on an optimal compression ratio of the compressor, a third condition determined based on outdoor temperature, and a fourth condition set as a default value.

A water chiller, a water output adjustment method, and an air conditioning system. The water chiller includes: at least two cooling towers used in parallel, a water pressure balance adjustment circuit, and a main control hoard, where each of the at least two cooling towers includes a water pressure pre-adjustment circuit, the main control board is configured to control the water pressure pre-adjustment circuit to realize real-time water output adjustment of the each of the at least two cooling towers, and control the water pressure balance adjustment circuit to achieve a water output balance adjustment among-multiple cooling towers.

An air conditioner including: a compressor; a heat exchanger fluidly connected to the compressor; a pressure sensor provided in a first flow path connecting an outlet of the compressor to an inlet of the first heat exchanger; a temperature sensor provided in a second flow path connected to an outlet of the heat exchanger; and a processor connected to the compressor, the pressure sensor, and the temperature sensor. The processor configured to: acquire a reference index value based on a first reference pressure measured by the pressure sensor and a first reference temperature measured by the temperature sensor, acquire a measurement index value based on a first measurement pressure measured by the pressure sensor and a first measurement temperature measured by the temperature sensor, and display a shortage of a refrigerant of the air conditioner based on the reference index value and the measurement index value.

The present invention discloses a method for operating a heat cool system during a sensor failure and system thereof. The method comprises determining, by controller, in the event of single or multi-sensor failure, a virtual value of at least a failed sensor based on a plurality of first and second predetermined values; determining the heat cool system run status based on a multi-sensor failure matrix in the event of multi-sensor failure; and obtaining, determining a real-time virtual value of at least the failed sensor based on an interlock value matrix for running heat and cool refrigeration cycles without stopping the heat cool system.