A control method for an air conditioning system includes: calculating an average heat exchange amount of a coil according to real-time operation information; setting a full-load air volume parameter and a full-load water volume parameter in a heat exchange model according to the real-time operation information and the heat exchange model, and calculating a full-load heat exchange amount; calculating a dynamic margin value based on the average heat exchange amount and the full-load heat exchange amount; determining whether the dynamic margin value is greater than a first preset condition or less than a second preset condition, so that the controller outputs a first control signal or a second control signal respectively to adjust a coil water inlet temperature; and when the dynamic margin value is less than the first preset condition and greater than the second preset condition, maintaining the current setting state.

In an air conditioner of the present embodiment capable of selecting either a fan rotation speed determined on the basis of a static pressure value and an air volume or a required fan rotation speed, motor control means determines, on the basis of the static pressure Pt, the fan rotation speed Rm of a fan motor that provides the air volume Av required by the user, and transmits the determined fan rotation speed Rm to an indoor unit control means. When the fan rotation speed Rm received from the motor control means is a prohibited rotation speed, the indoor unit control means transmits a correction fan rotation speed different from the prohibited rotation speed to the motor control means, and the motor control means drives the fan motor at the received correction fan rotation speed.

A refrigerant leak management system includes a controller is configured to receive a signal indicative of a refrigerant pressure within a refrigerant circuit and determine whether the refrigerant pressure is indicative of a refrigerant leak in the refrigerant circuit. In response to determining that the refrigerant pressure is indicative of the refrigerant leak, the controller is configured to activate a fan configured to motivate air proximate the refrigerant circuit.

An HVAC system includes a controller communicatively coupled to a subcool sensor, an outdoor temperature sensor, a compressor, and a blower of the HVAC system. For a first period of time, the controller periodically determines subcool values. For each determined subcool value, a corresponding compressor speed, outdoor temperature, and blower speed are determined. A baseline database is generated with baseline values associated with normal operation of the HVAC system. Following the first period of time, subcool values are determined based on the subcool signal. For each subcool value, a corresponding compressor speed, outdoor temperature, and blower speed are determined. The controller determines whether each subcool value satisfies a criteria based on the baseline database. If the criteria are not satisfied for at least a threshold time, the system is determined to be operating under a fault condition, and a corresponding alert is transmitted.

A modular valve system having fixed valve ports with frame openings on the exterior of each port. Corresponding connectors or plugs are designed to fit within the valve ports and be locked in place by a clip passing through the framed openings and around the connector or plug. The internal valve component may be electrically or mechanically controlled. The modular valve system may be connected to a vehicle coolant system to control fluid flow to a heat exchanger or bypassing the heat exchanger.

An HVAC system includes a suction-side sensor, a liquid-side sensor, an outdoor temperature sensor, and a controller. The controller determines that initial criteria are satisfied for initiating validation of the suction-side sensor and the liquid-side sensor. After determining that the initial criteria are satisfied, a suction-side property value, liquid-side property value, and outdoor temperature value are received. The controller determines whether a first validation criteria and a second validation criteria are satisfied. If both the first validation criteria and the second validation criteria are satisfied, the suction-side sensor, the liquid-side sensor, and the outdoor temperature sensor are determined to be functioning properly. Otherwise, the controller determines which one or more of the sensors are malfunctioning.

A flow control device is configured to control fluid flow in an HVAC system. The flow control device includes a valve, an actuator configured to open and close the valve, and one or more sensors. The flow control device further includes a fault detection and correction agent configured to receive data from the one or more sensors, analyze the data according to a set of rules, and detect whether one or more faults have occurred. In response to detecting a fault, the fault detection and correction agent is configured to either operate the actuator to open or close the valve or initiate a corrective action to be taken by another device in the HVAC system.

A heat cycle system and a control method. The heat cycle system includes: driving devices, one or a plurality of outdoor units, and a plurality of indoor units, which are connected by pipelines; a bypass pipeline for the plurality of indoor units, a bypass valve being disposed in the bypass pipeline; a pressure sensor that senses a pressure difference ΔP.sub.o across the plurality of outdoor units; and a controller that is preset with a pressure difference set value ΔP.sub.set, wherein the controller calculates a pressure offset parameter ΔP=ΔP.sub.o−ΔP.sub.set and adjusts an opening degree of the bypass valve based on the pressure offset parameter ΔP so that the pressure offset parameter ΔP approaches zero, and wherein the controller is preset with a first pressure offset threshold P.sub.1, and the controller is configured such that closed indoor units enter a bypass mode one by one when ΔP>P.sub.1, until ΔP≤P.sub.1.

A ventilator (1) includes: an air supply fan (2) to supply outdoor air to a room; an air exhaust fan (3) to exhaust indoor air, out of the room; and a total heat exchanger (4) which is made with partition boards (41) being moisture-permeable flat parts and with spacer boards (42) being corrugated parts, the partition boards and the spacer boards being alternately stacked, the total heat exchanger exchanging heat between the outdoor air and the indoor air; and thereby suppresses ice formation. The ventilator (1) includes: an indoor temperature sensor (7); an indoor humidity sensor (8); an outdoor temperature sensor (6); and a control unit (5) to control operation of the air supply fan (2) and the air exhaust fan (3) on a basis of at least one state quantity estimated by substituting the indoor air temperature, the indoor air humidity, and the outdoor air temperature in a total heat exchanger model formula (51a) representing characteristics of the total heat exchanger (4).

Disclosed herein are air conditioning systems including a refrigerant line configured to transport a refrigerant; a compressor in fluid communication with the suction line; and a controller in communication with a sensor configured to measure a characteristic of the refrigerant line. The compressor can be configured to move the refrigerant through the refrigerant line, and the refrigerant can have a first temperature at the outlet of the compressor. The controller can be configured to receive sensor data from the sensor indicating a current value associated with the characteristic of the refrigerant line; determine, based at least partially on the sensor data, that the characteristic of the refrigerant line is above a predetermined threshold; and output instructions for the compressor to perform one or more corrective actions.