An HVAC system includes a high-pressure subsystem and a low-pressure subsystem. After determining that refrigerant leak diagnostics should be performed, a controllable valve is closed between a condenser and compressor of the HVAC system. The compressor then operates until a predetermined input refrigerant pressure is reached. After the predetermined input refrigerant pressure is reached, operation of the compressor is stopped. After stopping operation of the compressor and waiting at least a predetermined wait time, the pressure in the low-pressure subsystem of the HVAC system is monitored. A rate of change of the pressure in the low-pressure subsystem is determined. If the rate of change is negative and a magnitude of the rate of change is greater than a threshold value, a leak location is determined to be in the low-pressure subsystem.

There is presented a heating, ventilation and air conditioning (HVAC) system for conditioning air within a chamber, the system comprising: an inlet, an outlet, and a conditioning unit, the conditioning unit comprising a fan, and a heat exchanger configured to exchange heat with the air within the conditioning unit, wherein during operation, air is urged through conditioning unit by the fan such that heat is exchanged between the air and the heat exchanger, wherein the fan is configured to vary the flow rate of air urged through the conditioning unit to thereby control the amount of heat transferred between the air and the heat exchanger.

Various embodiments include a method of controlling heat exchange via a terminal unit of a terminal-side circuit of a system for HVAC with a source-side circuit coupled to the terminal-side circuit comprising: reading a terminal-side supply temperature signal; producing a supply temperature from the terminal-side supply temperature signal; estimating a percentage demand signal as a function of the supply temperature; estimating an actual demand for power by rescaling a value of maximum available power by the percentage demand signal; comparing the actual demand for power to the value of maximum available power; and if the actual demand for power exceeds the value of maximum available power: producing a first flow control signal based on the value of maximum available power; and controlling a flow of a fluid through the source-side circuit based on the first flow control signal.

An air conditioner has a refrigerant circuit filled with a predetermined amount of a refrigerant, the circuit being formed of an outdoor unit and an indoor unit connected to each other by refrigerant piping, the outdoor unit having a compressor, an outdoor heat exchanger, and an expansion valve, the indoor unit having an indoor heat exchanger. The conditioner has an estimation model that estimates an amount of remaining refrigerant remaining in the circuit by using at least rotation frequency of the compressor, refrigerant discharge temperature at the compressor, heat exchanger temperature, degree of opening of the expansion valve, and outside air temperature, of operation state quantities indicating operation states during operation. The indoor heat exchanger has a sensor that is provided at an indoor heat exchanger intermediate portion connecting a first indoor heat exchanger port and a second indoor heat exchanger port to each other.

Provided are a control method and apparatus for increasing the amount of a circulating refrigerant, and an air conditioner. The control method includes: when a refrigerating capacity need is equivalent to a heating capacity need in the operation of an air-conditioning system, determining whether the discharge temperature of a compressor is greater than a preset safety alert value; if the discharge temperature of the compressor is greater than the safety alert value, adjusting the frequency of a fan of an outdoor heat exchanger; and when the discharge temperature of the compressor is not greater than the safety alert value, controlling to stop the adjustment of the frequency of the fan, and maintaining the air-conditioning system to operate at the adjusted current frequency of the fan.

A communication kit comprising a communication module configured to communicate with a thermostat, an indoor unit, and an outdoor unit; and a controller configured to generate an operation signal to be transmitted to the indoor unit and the outdoor unit, based on a signal received from the thermostat, wherein the controller is configured to determine an operation mode of the indoor unit and the outdoor unit based on an indoor temperature when a backup function of the thermostat is executed.

An air quality adjustment system includes an adsorption-desorption portion that adsorbs a target substance in air and desorbs the target substance adsorbed by the adsorption-desorption portion. The adsorption-desorption portion accumulates an energy in adsorbing the target substance and releases, in desorbing the target substance, at least part of the energy accumulated.

This disclosure aims to provide a technique for improving the accuracy of prediction. A first trained model for inferring labels for measurement data is generated based on a first data set. The first data set includes: combined data that are a combination of first measurement data, which are related to a first air conditioning apparatus, and labels set for the first measurement data; and second measurement data related to the first air conditioning apparatus.

Systems and methods for operating a water recovery system and include activating a plurality of dampers, a fan, and a refrigeration system of the water recovery system. The method includes measuring an ambient air temperature of the water recovery system based on data obtained from an ambient air temperature sensor. The method includes measuring one or more evaporator temperatures associated with an evaporator of the water recovery system based on data obtained from one or more evaporator temperature sensors. The method includes determining an optimal evaporator air temperature of the water recovery system based on the one or more evaporator temperatures and the ambient air temperature. The method includes setting a speed of the fan of the water recovery system based on the optimal evaporator air temperature.

A diagnostic system diagnoses an abnormality of a diagnostic object by using a plurality of diagnostic logics. The diagnostic system includes an acquisition unit, a determination unit, a generation unit, and an output unit. The acquisition unit acquires diagnostic object information relating to the diagnostic object. The determination unit determines whether each of the diagnostic logics is executable or not based on the diagnostic object information. The generation unit generates a diagnostic result including information relating to whether the diagnostic logics determined by the determination unit are executable or not. The output unit outputs the diagnostic result.