The answer to 'what is air handler' is an air handler, also known as an air handling unit (AHU), is a critical component of a central heating, ventilation, and air conditioning (HVAC) system. The air handler is responsible for circulating and conditioning the air throughout a home or building. It consists of a blower or fan, heating and/or cooling elements, and a filter to clean the air.
The air handler draws in air from the return ducts, filters it, and then either heats, cools, or dehumidifies the air before pushing it back out through the supply ducts and into the living spaces. This allows the HVAC system to maintain the desired temperature and indoor air quality for the occupants. Air handlers come in a variety of sizes and configurations to match the specific needs of a home or building.