a uniformed technician adjusts controls on a large rectangular metal unit with multiple pipes and ducts. He points to different gauges while explaining the system to a curious building manager. Warm air flows visibly through orange-tinted ducts while cool air moves through blue-tinted pipes. Fresh air enters through large ventilation shafts as stale air exits through different channels. The building manager nods as he watches the complex network of heating, cooling, and air circulation components working together. Other workers check temperature readings on various monitoring devices throughout the room. heating, ventilation, and air conditioning systems controlling the indoor climate