In this paper, the authors focus on the development of a portable system for indoor air monitoring and modeling realized by interfacing semiconductor gas sensors with microcontroller capable of wireless short-range communication through ZigBee module. An algorithm was developed to merge data from all of the sensors and to provide an intuitive graphical interface conveying the state of pollution. To evaluate the degree of health risk, results are categorized as good, moderate, unhealthy for sensitive groups, unhealthy and very unhealthy. Air Quality Index (AQI) developed by the US Environmental Protection Agency (EPA) was used since no such measures are presently available in the Philippines, where the system is intended to be used.