As known the electric energy is one of the most important factor of development, but using it causes bad environmental impacts due to depending on fuel as the source of electrical generation. Using renewable energy is still limited and needs a huge fixed costs, so it is important to reduce electrical consumption by monitoring and controlling equipment to achieve its function with lower consumption. HVAC sector is the most consumption part in buildings, therefor any saving in this sector will affect manifestly on the total electrical consumption in the building and this is done by control system. Control systems are in continuous improving, so it is needed to exploit them in saving electrical energy. In this research, studying control of VAV system and designing fuzzy logic controller to drive supply fan in order to reduce its electrical consumption, this is performed through designing practical prototype of the supply fan with its tools and software which are designed to view the electrical energy saving which we gain it by using fuzzy logic controller.