A typical HVAC system consists of a heating unit, an air conditioning unit and the ventilation fan or blower at the air handler unit. A thermostat is used to control the conditioning of the air in a desired space by sending control signals to the HVAC furnace or heater, the HVAC air conditioning and the HVAC blower or ventilation fan housed in a PCB located at the air handler unit. The HVAC fan controller typically operates the ventilation fan for 0 to 90 seconds after the furnace or air conditional compressor cycles off.
Studies show that even after this automatic 90 second extension, the furnace surface / air conditioner cooling coil still has latent energy left over. This wasted energy is not delivered to the desired space when the ventilation fan stops blowing. HVAC systems need a secondary controller (InteliFan Microprocessor) for