Often shown as diagonal lines parallel to the wet bulb lines. Enthalpy (h) is the total energy in the air (sensible heat + latent heat). This is the "checkbook" of the chart—it tells you how much energy your air conditioner or heater must add or remove.
Today, most engineers use digital psychrometric charts inside Building Management Software (BMS) or Excel plugins. You can click a point and instantly get all properties. However, the remains the gold standard for teaching. There is no substitute for physically drawing a line from 95°F dry bulb, 75°F wet bulb to the saturation curve to understand why your glasses fog up when you walk inside. psychrometric graph
Engineers use the chart to calculate the "Coil Load"—how much energy a cooling coil must remove to take air from outside conditions to the desired supply air condition. By plotting the supply air point and the room air point, they can calculate the airflow required to offset room heat gains. Often shown as diagonal lines parallel to the wet bulb lines
A psychrometric graph, or , is a fundamental tool for HVAC engineers, meteorologists, and scientists that visually represents the thermodynamic properties of moist air. While it might look like a chaotic web of lines at first glance, it serves as a powerful "map" for determining how air behaves as it is heated, cooled, or humidified. The Core Components of the Graph There is no substitute for physically drawing a