Abstract: A control strategy for heating, ventilating, and air-conditioning (HVAC) units used to condition the environment in data centers and other commercial buildings such as retail stores with an open-plan design is provided to coordinate the operation of the actuators of the HVAC units. A supervisory controller receives feedback signals from a plurality of environmental sensors and uses a set of references values to determine control signals to the actuators of the HVAC units. A pseudoinverse of a transfer function matrix G may be used to determine the control signals from errors in the feedback signals relative to the reference signals.

Abstract: Systems, apparatus, and methods of controlling a variable-speed fan of an environmental maintenance module that controls temperatures of a plurality of zones of a building are provided. A first critical zone of the building is identified by analyzing the first zone temperature errors, which are used to determine a final speed setting of the variable-speed fan. Systems, apparatus, and methods of calibrating an environmental maintenance module that controls a temperature of a zone of a building are also provided. A location parameter is calculated for a plurality of zone temperatures, and a scale parameter is computed that quantifies a variation of the zone temperatures relative to a location parameter. A first temperature setpoint for the zone is determined and used in controlling the temperature of the zone.

Abstract: Systems, apparatus, and methods for controlling environmental maintenance modules (e.g. HVAC units) using sensors are provided. Values measured by the sensors can be used to determine a change in operation levels of the modules to keep the sensor values within a desired range. For example, a stopped module can be increased or started for more cooling when a sensor temperature is too hot. The module predicted to have the greatest effect on the temperature of hot sensor can be started. A transfer matrix, which provides a relation between a change in operation level and resulting sensor changes, can be used to perform the above predictions. As another example, a module can be stopped (or otherwise have an operation level decreased), if the sensor temperatures are within range, and the decrease in operation level is predicted not to cause an out-of-range condition.

Abstract: A control strategy for supply fans in constant-volume heating, ventilating, and air-conditioning (HVAC) systems that reduces the speed of the fan at part-load conditions is provided. The invention consists of a constant-volume HVAC system, wireless discharge air temperature sensors, wireless hot source and cold source temperature sensors, and a wireless controller coupled to a fan modulation device. The controller includes a finite state machine that switches between a high-temperature control mode and a low-temperature control mode. The controller also includes a calculator that calculates a high temperature setpoint and a low temperature setpoint as a function of the hot source and cold source temperatures. In high temperature control mode, the controller compares the maximum discharge air temperature with the high temperature setpoint, and it commands the fan modulating device so that the maximum discharge air temperature remains close to the high temperature setpoint.

Abstract: A control strategy for heating, ventilating, and air-conditioning (HVAC) units used to condition the environment in data centers and other commercial buildings such as retail stores with an open-plan design is provided to coordinate the operation of the actuators of the HVAC units. A supervisory controller receives feedback signals from a plurality of environmental sensors and uses a set of references values to determine control signals to the actuators of the HVAC units. A pseudoinverse of a transfer function matrix G may be used to determine the control signals from errors in the feedback signals relative to the reference signals.