Which of the following is not a function of the HVAC system?

• A. Thermodynamics
• B. Ventilation
• C. Humidification
• D. Temperature control

Answer: (A)

Think about what an HVAC system actually does in a building. It is designed to control the indoor environment by bringing in fresh air or exhausting stale air (ventilation), adding moisture when needed (humidification), and keeping the indoor temperature within a comfortable range (temperature control). Thermodynamics, on the other hand, is the science that explains how energy moves and changes form—how heat transfers, how work is done by components like compressors, and the relationships between pressure, temperature, and volume. The system uses these thermodynamic principles to operate, but it doesn’t perform “thermodynamics” as a separate function. That’s why thermodynamics is not a function of the HVAC system, while ventilation, humidification, and temperature control are.