Heating, ventilation, and air conditioning (HVAC) play a crucial role in maintaining comfortable and healthy environments across various settings. This includes residential structures like single-family homes, apartment buildings, hotels, and senior living facilities, as well as larger industrial and office buildings such as skyscrapers and hospitals. HVAC systems are also vital in vehicles like cars, trains, airplanes, ships, and submarines, as well as in marine environments. These systems regulate temperature and humidity by using fresh air from outdoors to ensure safe and optimal conditions.