HVAC Journeyman Practice Exam 2025 - Free HVAC Practice Questions and Study Guide

The primary function of an air-handling unit (AHU) is to distribute supply air within a building. An AHU is a critical component of HVAC systems and is designed to take in air, condition it (which may include heating, cooling, dehumidifying, or filtering), and then distribute it to various spaces throughout the structure. This ensures that each area maintains a comfortable temperature and air quality, which are essential for occupant comfort and building efficiency.

While measuring indoor air quality is important for a comprehensive HVAC system, this function is generally performed by specialized sensors and systems rather than by the AHU itself. The unit plays a role in improving air quality through filtration and ventilation, but its primary responsibility is not to conduct air quality measurements.

Providing heating is a function of an AHU when it includes heating elements, but its role is much broader than heating alone. An AHU typically handles both heating and cooling, making its function more diverse.

Exhausting air is another function that may be associated with HVAC systems, but this is typically carried out by exhaust fans or systems specifically designed for that purpose, not the air-handling unit. The AHU’s focus is more on circulating conditioned supply air rather than removing air from the environment.