Patent attributes
The efficient fan controller includes a microprocessor receiving at least one signal input from thermostat/equipment control terminals to control a fan relay to operate a system fan. The microprocessor monitors a thermostat call for cooling/heating duration and determines a variable fan-off delay based on the cooling/heating cycle duration, and at an end of a cooling/heating cycle energize the fan relay to operate the system fan for the variable fan-off delay. The fan controller avoids false thermostat activation signals and includes a common wire adapter to provide continuous power to a smart communicating thermostat and is configured to evaluate floating, zero, rectified, false positive and active input signals. The fan controller can be embodied on a forced-air-unit control board or thermostat. The fan controller installation methods ensure the system fan/blower operates at high speed for heating and cooling to improve thermal comfort, efficiency and satisfy the thermostat sooner to save energy.