What blows air in HVAC?

In HVAC systems, air is blown by a fan or blower. The fan is typically powered by an electric motor and is responsible for circulating air throughout the system. The fan draws air from the return ducts and pushes it through the supply ducts, where it is then distributed to the various rooms in the building. The fan also helps to maintain the desired temperature and humidity levels in the building. Additionally, the fan helps to remove any contaminants from the air, such as dust, pollen, and other particles.