What are openings that provide air for combustion, ventilation, and dilution termed?

The term used to describe openings that provide air for combustion, ventilation, and dilution is indeed best represented by "Combustion, Ventilation, and Dilution Air Openings." These openings serve essential functions in ensuring that adequate air supply is available for the proper operation of combustion appliances, which rely on the right mixture of air and fuel to operate efficiently and safely.

Combustion air is critical for the burning process in heating equipment, while ventilation air is necessary for maintaining air quality and comfort within a building. Dilution air helps to safely remove exhaust gases from indoor spaces, minimizing pollutants and ensuring safety for occupants.

The other options do not encompass the full scope of these openings. "Air Intake Screens" specifically refer to protective elements designed to prevent debris from entering air intake systems but do not address the broader requirements for combustion and ventilation air. "Exhaust Ducts" specifically relate to the removal of air from a space, not the intake required for combustion and ventilation. Lastly, "Ventilation Shafts" typically denote vertical conduits that assist in air movement but do not specifically denote the openings required for air necessary for combustion or dilution processes.