A device configured to operate a Heating, Ventilation, and Air Conditioning (HVAC) system and to receive an audio signal from a microphone while operating HVAC system. The device is further configured to generate a representation of the audio signal, to compare one or more audio signatures to the representation of the audio signal, and to determine that an audio signature from among the one or more audio signatures is not present within the representation of the audio signal. The device is further configured to determine a fault type that is associated with the audio signature that is not present within the representation of the audio signal, to identify a component identifier for a component of the HVAC system that is associated with fault type, and to output the component identifier.

A device configured to operate a Heating, Ventilation, and Air Conditioning (HVAC) system and to receive an audio signal from a microphone while operating HVAC system. The device is further configured to generate a representation of the audio signal, to compare one or more audio signatures to the representation of the audio signal, and to determine that an audio signature from among the one or more audio signatures is not present within the representation of the audio signal. The device is further configured to determine a fault type that is associated with the audio signature that is not present within the representation of the audio signal, to identify a component identifier for a component of the HVAC system that is associated with fault type, and to output the component identifier.

An air conditioner including a heat exchanger; a blower fan; a compressor; and a controller. The controller performs: a cooling process in which the compressor is operated to compress a circulating refrigerant, the heat exchanger performs heat exchange between the refrigerant and air, and the blowing fan is operated to blow air to the heat exchanger. The controller performs a drying process including: performing, a blowing process in which the blower fan is operated to blow air to the heat exchanger while the compressor is stopped, and performing a heating process in which the refrigerant is circulated in a direction that is changed from that of the cooling process, the blower fan is operated to blow air to the heat exchanger, and the compressor is operated to compress the refrigerant, thereby heating the surface of the heat exchanger and drying water condensed on the surface of the heat exchanger.

Methods and systems for reconnecting a device with an expired device operational certificate in a building management system (BMS) are disclosed. One method includes identifying that a device operational certificate of a first device has expired, sending an instruction to a second device to accept the expired device operational certificate as valid, receipt of the instruction causing the second device to relax an expiration date and accept the expired device operational certificate as valid, and delivering a replacement device operational certificate to the first device to replace the expired device operational certificate.

Methods and systems for reconnecting a device with an expired device operational certificate in a building management system (BMS) are disclosed. One method includes identifying that a device operational certificate of a first device has expired, sending an instruction to a second device to accept the expired device operational certificate as valid, receipt of the instruction causing the second device to relax an expiration date and accept the expired device operational certificate as valid, and delivering a replacement device operational certificate to the first device to replace the expired device operational certificate.

An authentication system acquires, as authentication information, information related to a device, information related to a user or information related to a user terminal, and information indicating that the user or the user terminal is in a vicinity of the device. The authentication system performs authentication of the acquired authentication information, and permits the user for whom or the user terminal for which the authentication is successful to manage the device.

A computer implemented system and process of analyzing real-time measurements of a one or more air quality sensors to provide an calculated estimate of airborne virus infection and air quality evaluation from current air quality measurements, advise those at risk, advise responsible parties of recommended actions to take, and in some embodiments take direct action in communication of instructions to air filtration and treatment equipment and HVAC systems to improve outside air flow, increase filtration, treat contaminated air and reduce humidity and reduce the risk of airborne virus transmission. Sensor data, calculated airborne infection risk, air quality, warnings and reports are created and distributed to network connected devices.

A computer implemented system and process of analyzing real-time measurements of a one or more air quality sensors to provide an calculated estimate of airborne virus infection and air quality evaluation from current air quality measurements, advise those at risk, advise responsible parties of recommended actions to take, and in some embodiments take direct action in communication of instructions to air filtration and treatment equipment and HVAC systems to improve outside air flow, increase filtration, treat contaminated air and reduce humidity and reduce the risk of airborne virus transmission. Sensor data, calculated airborne infection risk, air quality, warnings and reports are created and distributed to network connected devices.

A temperature control system. The control system includes a flow sensor configured to monitor water flow through a valve, an actuator coupled to the valve, and a first controller configured to establish a setpoint for a second controller. The second controller monitors fluid flow through the valve and combines a weighted first command from the first controller and a weighted second command from the second controller to generate a control signal, wherein combining the weighted first command and the weighted second command is based on the reliability of the flow sensor. The second controller further controls the actuator based on the control signal.

A temperature control system. The control system includes a flow sensor configured to monitor water flow through a valve, an actuator coupled to the valve, and a first controller configured to establish a setpoint for a second controller. The second controller monitors fluid flow through the valve and combines a weighted first command from the first controller and a weighted second command from the second controller to generate a control signal, wherein combining the weighted first command and the weighted second command is based on the reliability of the flow sensor. The second controller further controls the actuator based on the control signal.