Disclosed is an HVAC (heating, ventilation and air-conditioning) system which comprises a fluid flow duct (1), a fluid flow valve (7) which is arranged therein and has a valve body (5) in the fluid flow duct (1) and a valve motor (15) which moves the valve body (5), a control circuit for activating the valve motor, a sensor (8) in the fluid flow duct (1) and an evaluation module for evaluating signals of the sensor. To produce an automated functional control, the following procedure is adopted: a first actuation signal is preset for the valve motor by the control circuit, and the actuation signal corresponds to a first setpoint position of the valve body (5), registration of a first signal of the sensor (8) by the evaluation module, and determination of a functional diagnosis of the fluid flow valve on the basis of the first signal of the sensor.

A system having a mixed air box with inputs of return air from a space or spaces of a building, and of outside air. The mixed air box may have an output of discharge air to the space or spaces of the building. The air from the output may be return air that is conditioned with cooling, heat, or outside air. A damper may be situated at the input of outside air to the mixed air box. A temperature sensor may be positioned at the input for outside air and at the output of discharge air. A cooling mechanism may be at the output of the discharge air. The temperature sensor may be downstream from the cooling mechanism. An economizer may have connections with the damper, the temperature sensor and the cooling mechanism.

An HVAC controller may wirelessly communicate with a mobile wireless device that provides a user interface for interacting with the HVAC controller. In some cases, the communication module wirelessly receives a sensed parameter from a remote wireless sensor in a living space of the building and receives a wired input from a return air sensor. A controller may be operatively coupled to the communication module and may control the HVAC system based at least in part on the sensed parameter from the remote wireless sensor when the sensed parameter from the remote wireless sensor is available and, in some cases, control the HVAC system based at least in part on the return air parameter when the sensed parameter from the remote wireless sensor is not available.

A heating, ventilation, and air conditioning (HVAC) system actuator including a stator magnet and a rotor magnet. The rotor magnet turns an axle connected to an airflow door such that rotation of the axle moves the door and generates waveforms. The number of waveforms generated corresponds to how much the axle has rotated. The stator magnet is magnetized to a saturated state, thereby providing the waveforms with a consistent shape that is consistently detectable by a climate control pulse count module.

A fluid distribution apparatus that can serve as a fluid metering device that is operable on a single platform by building automation systems. The building automation system may be controllable by a single software system or network accessible locally on site or remotely off site. The fluid distribution apparatus can operate independently or coupled with multiple like apparatuses for system operation. It is a high turndown, self-balancing system which allows for continuous commissioning with built-in fault diagnostic systems and that may be used as a supply system, exhaust system, or a combination thereof. The fluid distribution apparatus includes fluid metering devices that operate progressively based on unique actuation mechanisms and/or algorithms that allow for precise flow control and feedback to self-balance and commission the system.

A state-based control system for an air handling unit (AHU) includes a finite state machine configured to transition between a high cooling load state and a low cooling load state. In the high cooling load state, the system maintains the temperature of a supply airstream provided by the AHU at a fixed setpoint and controls the temperature of a building zone by modulating the speed of a supply air fan. In the low cooling load state, the system operates the supply air fan at a fixed speed and controls the zone temperature by modulating an amount of cooling applied to the supply airstream by one or more cooling stages. A feed-forward module manages disturbances caused by adding or shedding cooling stages by applying a feed-forward gain to the supply air fan setpoint.

An apparatus and method for measuring or controlling the Outdoor Air Fraction (OAF) ratio through economizer or outdoor air dampers and cabinet to total system airflow and mixed-air humidity ratio and wetbulb temperature for HVAC equipment. An OAF exceeding the minimum regulatory requirements wastes energy and contributes to global warming. OAF is used to optimize economizer damper position either manually or automatically using an economizer Fault Detection Diagnostic controller and actuator to meet minimum outdoor airflow requirements. After the outdoor air damper position is optimized, the mixed-air humidity ratio and mixed-air wetbulb temperature are determined and used with the measured mixed-air drybulb and supply-air drybulb temperatures to evaluate evaporator airflow, cooling capacity, and heating capacity, and, if necessary, provide a visual or electronically-transmitted error code signal indicating maintenance requirements to check or correct economizer damper position, cabinet leakage, airflow, cooling or heating capacity, and/or other faults for the HVAC system.

A system and method for minimizing indoor infection risk and improving indoor air quality (IAQ) while maximizing energy savings. The system integrates occupancy detection and forecasting, outdoor weather conditions and forecasting, indoor infection risks and air quality modeling, any tunable air filtration, the clean air delivery rate, and any portable air cleaners. The system outputs the total amount of outdoor air intake, the air temperature of the supply air into the space, the supply air flow rate into the space, the operation mode of tunable air filtration/purification/disinfection, the operation mode of the in-room air cleaner, and space/room temperature set-points, and thus can serve as the central controller for an HVAC system.

Examples provide a system for a temperature-controlled receiving tunnel. A main body includes an interior compartment and a set of adjustable bulkheads configured to create a set of temperature-controlled zones within the interior compartment. A set of cooling devices are configured to adjust an internal temperature of the set of temperature-controlled zones within the interior compartment. A control device analyzes dynamic truck delivery data and ambient temperature data to generate a predicted cooling time and a cooling initiation time. The predicted cooling time comprises an estimated quantity of time after the cooling initiation time to reach a target temperature within a selected zone in the set of temperature-controlled zones.