We, humans, spend 80-90% of our lives indoors. Thereby the building has two main functions, namely: protect their occupants and provide the occupants a comfortable indoor environment. However, the last one seems a big challenge, since every individual is different from each other, based on the factors as age, gender, clothing, activity, positioning within the building or body mass. At the current situation, building service systems in most buildings are maintained at a steady level based on fixed schedules and average values. As a result, the thermal comfort of building occupants are hardly met. In the meantime, the same building service systems account for up to 50% of the energy consumption in the commercial sector. A response to this challenge is started with the introduction of personal comfort systems, which focuses on the individual occupants instead of average values of a large group of people. However, we are not there yet. This thesis is contributing to the response by focusing on efficient usage of personal comfort systems and tries to close the loop between the building service system and building occupants by finding a proper balance between providing thermal comfort and reducing energy consumption.