Which device is commonly used to distribute conditioned air within a building?

An air handler is a crucial component in a building's heating, ventilation, and air conditioning (HVAC) system. Its primary function is to circulate and distribute conditioned air throughout the building. It achieves this by taking in air, filtering it to remove impurities, and then using heating or cooling coils, as well as fans, to adjust the air temperature before pushing it through ducts into various spaces.

The design of an air handler typically includes features that make it suited for these tasks, such as blowers to move air effectively, filters for air quality, and often a network of ducts for air distribution. While other devices like chillers and heat pump systems play important roles in temperature regulation, they do not directly distribute air within a building. A chiller, for instance, primarily serves to remove heat from a fluid through a vapor-compression or absorption refrigeration cycle and is typically part of a larger cooling system, while a heat pump provides heating or cooling but also does not distribute air on its own. Similarly, fan coil units are used to regulate temperature at a localized level and rely on a primary air handling system to bring in conditioned air. Thus, the air handler is specifically designed to perform the task of conditioning and distributing air, making it the correct