In modern office buildings, the common trend is to use state of the technology to ensure the users to get thermally comfortable in order to produce maximum work efficiency. From the statistical studies so far on comfort index vs. work efficiency of users, the most widely adopted index is the Predicted Mean Vote (PMV). Based on this index, this work proposes a control scheme on neural network and fuzzy logic, for modifying the environmental conditions of a closed indoor space, by regarding not only the climatic indoor variables but also the activity level and clothing index of the space users. In this work along with temperature control the speed of the fan has also been taken into consideration