Air-conditioning systems provide optimal conditions for work, human health, and quality of living. At the same time, they are one of the greatest household energy consumers. Therefore, the Building Energy Management System sets high demands on their control, aiming to reduce energy consumption while ensuring indoor comfort. The classic control technique cannot satisfactorily deal with the energy-efficient stabilization of basic interacting microclimate parameters. The fuzzy logic approach offers intelligent means for the stabilization of the coupled temperature, humidity, and fresh air supply with low energy requirements. The aim of this study is to develop a model-free design method for a two-variable PI fuzzy controller for temperature and humidity control that ensures indoor comfort and reduces energy consumption by supervisory fuzzy tuning.