Which of the following is NOT a primary function of HVAC systems?

The primary functions of HVAC (Heating, Ventilation, and Air Conditioning) systems include heating, cooling, and humidification. These functions are integral to maintaining indoor environmental quality and comfort levels in buildings. Heating provides warmth during colder months, cooling helps maintain comfortable temperatures during warmer periods, and humidification regulates the moisture levels in the air, which can impact health and comfort.

Fuel generation, on the other hand, is not a function performed by HVAC systems. While HVAC systems may utilize fuel to operate (for instance, a furnace might use gas or oil as a fuel source), the generation of that fuel is outside the scope of what HVAC systems are designed to do. Instead, HVAC systems focus on managing and controlling the climate within a space once the necessary energy has been supplied, but they do not produce or generate fuel themselves. Therefore, fuel generation is not considered a primary function of HVAC systems.