of a computerized processing unit environmental sensors and an interface to an hvac system the ade includes the ability to connect to the hvac conditioning control points fan command and fan speed and an economizer actuator it has the ability to provide standard low voltage thermostat type control signals to hvac equipment and modulating resistive or voltage signal to the economizer actuator the ade can be used with either new or existing equipment the ade can be implemented in a commercially available controller like an easy io 32 a plc like an abb ac500 or embedded directly on a programmable chip like a microchip pic24 at its core is the ability to store instructions accept commands retain setpoints and react to sensor inputs the ade can use temperature and humidity sensors to monitor environmental conditions the sensor will provide a varying electrical signal based upon the conditions for example the temperature sensor could be a 10k ntc thermistor that changes the resistive value based on temperature changes for humidity measurements the sensor could be a 0 10vdc sensor where the voltage output changes based on changes in the humidity it is also required for the ade to receive indication of the space conditions this.