Intelligent Ventilation System(IVS) is an environment friendly product for BTS rooms. In the era of electricity crisis, this Microcontroller based control system not only reduces the consumption of power in BTS rooms but also minimizes the emission of Carbon-di-Oxide from Air Conditioner(AC)of a BTS room. The whole controlling is done in this project by a PIC Microcontroller IC 16F877A. So IVS is a Microcontroller based electronics device that maintains the overall environment of a BTS room by controlling a Fan unit, a Filter unit and an AC by observing the room temperature, room humidity and battery voltage level of a BTS room.