The HVAC systems account for approximately 40% of the total power consumption of a building. Thus, HVAC systems should optimize the available energy. Energy Management Systems (EMS) or Building Energy Management Systems (BEMS) monitor and manage HVAC systems. This software sends notifications when the HVAC system is not working efficiently. These systems give intelligent reports on identifying problem areas and provide recommendations for solving those problems. They also integrate control systems to automate responses. Also, heating and cooling systems are automatically adjusted according to the temperature outside. So, constant monitoring ensures that neither overcooling nor overheating takes place. Brands like Mitsubishi and Bryant provide energy-efficient HVAC systems.