Heating: Used to heat a space during cold weather. This can be achieved through boilers, electric heaters, or heat pumps.
Ventilation: This is perhaps the most important part for health. It ensures the inflow of fresh air from outside and removes accumulated dust, humidity, unpleasant odors, and carbon dioxide (CO2).
Air Conditioning: Designed to cool the air and regulate humidity during hot weather, creating a comfortable microclimate.