Abstract: The present disclosure is directed to a method for reducing power consumption of a sensor. The method includes determining if a predetermined condition has been met to change at least one of a sensing rate or a sensor resolution, and changing at least one of the sensing rate or sensor resolution if it is determined that the predetermined condition has been met.

Abstract: The present disclosure is directed to a method for reducing power consumption of a sensor. The method includes determining if a predetermined condition has been met to change at least one of a sensing rate or a sensor resolution, and changing at least one of the sensing rate or sensor resolution if it is determined that the predetermined condition has been met.

Abstract: A refrigerant system includes a controller that enables the system to dehumidify the air in a room without relying on a humidistat and without having to operate the system's compressor and electric heater at the same time. To dehumidify the air, the system's compressor, supply air fan, and outside air damper are controlled in a manner similar to other systems operating in a cooling mode when the room temperature is above a certain setpoint temperature. When the room temperature falls below the setpoint, however, the operation changes significantly. The controller closes the outside air damper, decreases the speed of the fan, and continues operating in this manner until the room temperature decreases to a subcooling temperature limit. The subcooling temperature limit is less than a predetermined limit that is used during the system's normal cooling mode.

Abstract: A refrigerant PTAC system, such as those commonly found in hotel rooms, can be selectively configured in a hardwire or wireless configuration with respect to its thermostat. The system is controlled in response to the better of two temperature sensors, which is determined based on the PTAC's configuration and the validity of the readings provided by the sensors. While the PTAC is controlled in response to a preferred temperature sensor, the alternate sensor may be monitored for diagnostics or other reasons. In the event that the preferred sensor fails to provide valid readings, the controller automatically switches to controlling the system in response to the alternate sensor. To minimize manufacturing costs and the variety of stocked parts, the PTAC's controller preferably includes two substantially identical transceivers.

Abstract: A refrigerant system includes a controller that enables the system to dehumidify the air in a room without relying on a humidistat and without having to operate the system's compressor and electric heater at the same time. To dehumidify the air, the system's compressor, supply air fan, and outside air damper are controlled in a manner similar to other systems operating in a cooling mode when the room temperature is above a certain setpoint temperature. When the room temperature falls below the setpoint, however, the operation changes significantly. The controller closes the outside air damper, decreases the speed of the fan, and continues operating in this manner until the room temperature decreases to a subcooling temperature limit. The subcooling temperature limit is less than a predetermined limit that is used during the system's normal cooling mode.

Abstract: A refrigerant PTAC system, such as those commonly found in hotel rooms, can be selectively configured in a hardwire or wireless configuration with respect to its thermostat. The system is controlled in response to the better of two temperature sensors, which is determined based on the PTAC's configuration and the validity of the readings provided by the sensors. While the PTAC is controlled in response to a preferred temperature sensor, the alternate sensor may be monitored for diagnostics or other reasons. In the event that the preferred sensor fails to provide valid readings, the controller automatically switches to controlling the system in response to the alternate sensor. To minimize manufacturing costs and the variety of stocked parts, the PTAC's controller preferably includes two substantially identical transceivers.

Abstract: A method of selecting a ventilation control strategy from among a plurality of ventilation control strategies. The method comprises the steps of: determining if a CO2 signal is present and valid; selecting a CO2 based ventilation control strategy if the CO2 signal is present and valid; selecting a second ventilation control strategy if the CO2 signal is not present or is invalid; and operating using the selected strategy. The selection step occurs in a zone controller.

Abstract: A method of determining and controlling a load by a controller. The method comprises the steps of transmitting a signal for a first predetermined time period on an electrical line having a load in parallel with a capacitor; monitoring the electrical line for electrical activity within a second predetermined time period following the first time period; and controlling the load in response to the presence or absence of the electrical activity.

Abstract: The variable opening of a pressure independent supply air valve for a building ventilation system is controlled in response to a standard airflow transducer whose output is modified to emulate a close tolerance transducer. In a calibration mode, a microcomputer based control closes the valve and a summing amplifier reduces the transducer output by an amount equal to a compensation signal provided by the microcomputer. Once the output is reduced to a predetermined desired level, the value of the compensation signal is stored in memory for later use during a run mode. In the run mode, the actual supply airflow rate is determined based upon the transducer output less the compensation signal. And the control adjusts the position of the valve until the actual airflow rate meets a desired airflow rate as determined by a room thermostat.

Abstract: A pressure independent variable air volume valve (VAV valve) functions as a pressure dependent valve upon detecting a malfunctioning airflow indicator. Under normal operating conditions, the VAV valve modulates supply airflow to a comfort zone in response to the zone temperature and the rate of airflow through the valve. If the airflow indicator fails, the VAV valve modulates the supply airflow in response to the zone temperature, independent of the airflow indicator.