Neatafan 250mm diameter 3kw tc3 thyristor controlled electric air heater neatafan 250mm 3kw tc3 p an electric air heater from neatafan designed to act as a pre or reheater in small branch ducts from a main air handling unit ahu or on systems where the supply fan is controlled from elsewhere there is no fan run on timer so the heater relies on a volt free or 230v start signal and stays off until airflow is detected by the combined dtfs airflow and temperature sensor p p the heater can