The study of air and its properties is called what?

• A. Thermodynamics
• B. Psychrometrics
• C. Aerodynamics
• D. Hydraulics

Answer: (B)

Understanding moist air and how its properties interact is the focus here. Psychrometrics is the study of moist air properties such as temperature, humidity, humidity ratio, pressure, dew point, and enthalpy, and how those properties change during heating, cooling, humidifying, or dehumidifying. This field is essential in HVAC because equipment treats air to meet comfort and process requirements, and the psychrometric chart helps predict how processes affect humidity and temperature. The other topics describe broader energy transfer (thermodynamics), air flow around objects (aerodynamics), or liquids in pipes (hydraulics), not specifically the properties of air and moisture. So the correct term for the study of air and its properties is psychrometrics.