What is the purpose of combustion air ducts in HVAC systems?

The purpose of combustion air ducts in HVAC systems is specifically to supply air for combustion processes. In systems that rely on burning fuel—such as gas furnaces or boilers—adequate combustion air is essential for efficient and safe operation. These ducts direct fresh air from outside the building directly to the combustion appliance, ensuring that the fuel can burn properly and providing the necessary oxygen.

This is crucial not only for maximizing energy efficiency but also for preventing dangerous situations, such as the production of carbon monoxide due to insufficient oxygen for combustion. By ensuring a steady and adequate supply of air through the combustion air ducts, the HVAC system can operate safely and effectively.

The other options, while related to HVAC operations, do not pertain directly to the function of combustion air ducts. For example, enhancing cooling efficiency, ventilating the living space, and eliminating humidity are all important aspects of HVAC systems, but they are served by different components and mechanisms, not by the combustion air ducts.