How To Read A | Psychrometric Chart

These are the curved lines that mimic the shape of the saturation curve but sit further to the right. They are usually labeled as 10%, 20%, 30%, etc.

| Line/Curve | Symbol | Shape | Location on Chart | | :--- | :--- | :--- | :--- | | Dry Bulb Temperature | DBT | Vertical, straight lines | X-axis (bottom) | | Humidity Ratio | W or HR | Horizontal, straight lines | Y-axis (right side) | | Saturation Curve | 100% RH | Curved line (left edge to top) | Upper left boundary | | Relative Humidity | RH | Curved, concave lines | Between saturation and dry region | | Wet Bulb Temperature | WBT | Diagonal, straight lines | Slanting down to the right | | Specific Volume | v | Diagonal, straight lines | Similar to WBT but steeper | | Enthalpy | h | Diagonal, straight lines | Parallel to WBT lines | how to read a psychrometric chart