Fault detection diagnostic variable differential variable delay thermostat

摘要: A Fault Detection Diagnostic (FDD) variable differential and fan-off delay Heating Ventilating Air Conditioning (HVAC) thermostat control method. The FDD method detects a fan-on setting, reports alarm, overrides turns off an HVAC fan. detects, reports, corrects short-cycle by providing based on: cooling or heating cycle duration, off-cycle time. is Conditioned Space Temperature (CST), comparing current CST to the measured during delay, rate of change with respect time (dT/dt), dT/dt reaches inflection point, crosses fan-off-delay differential, temperature split, rise, outdoor air temperature, supply these parameters.