If you work with air conditioning, drying processes, or building ventilation, you have likely used a psychrometric chart. While most people focus on dry-bulb temperature, humidity ratio, and enthalpy, one property is critical for sizing fans and ducts: specific volume .
This article explains what specific volume is, how to find it on the chart, and why it matters in real-world applications. Specific volume is the inverse of density. It represents the volume occupied by a unit mass of moist air. psychrometric chart specific volume
[ v = \frac1\rho ]