AHU`s(Air Handling Unit`s) are work hard to heat or cool the air inside the building, because they hidden in the ceiling cavity or at the plantroom you may not notice them at all. But they need a trained eye and ear to notice if something wrong. Unfortunately the unit on the pictures are had a lack of maintenance and the unit broke down. The unit fan module now beyond repairable state, as the motor bearing crushed and the rotor(the spinning part) damaged the stator(the still part with the winding). New Module has to be ordered with a 20 working day lead time…not a good new during the winter.