HVAC systems are used in the United States to provide a comfortable indoor environment. Heating, ventilation, and air conditioning systems are designed to regulate temperature, humidity, and air quality. HVAC systems are used to maintain a comfortable temperature in the home or office, as well as to reduce energy costs. They also help to reduce the spread of airborne illnesses and allergens, and can help to improve air quality. HVAC systems are essential for providing a safe and comfortable environment for Americans.