Efficient energy use in buildings, especially for HVAC systems, is crucial as they consume over 30% of global energy. Balancing energy savings with user comfort is key. A Smart HVAC system was developed using Social Internet of Things to optimize energy costs while maintaining user comfort. By analyzing building thermal profiles, the system can adjust HVAC working times accordingly. Results show that this system can adapt to user needs, ensuring comfort while reducing energy costs compared to traditional methods.