A novel design of speed control of fan based on room temperature using PWM technique is proposed in this paper. The simulation of the system is working properly and the design is appropriate according to the modern needs and technology. The speed of fan depends on the room temperature and there is no need for regulating the speed manually. Various graphs have been plotted to show the varying relationships between different parameters. PWM technique is found to be appropriate for controlling fan speed according to room temperature. This design can be further extended in terms of area and power at layout and characteristic level by using Advanced VLSI applications.