Psycrometric Chart

Overview

Engineering reference data for Psycrometric Chart in basics.

Key Formulas

Ohm's Law

$V = IR$

Voltage = Current × Resistance.

Newton's Second Law

$F = ma$

Force = mass × acceleration.

Conservation of Energy

$E_{in} = E_{out} + \Delta E_{stored}$

Energy balance.

Variables

Practical Application

A psychrometric chart graphically represents the thermodynamic properties of moist air at a given pressure. The condition specified—7500 feet elevation and 22.653 inches of Mercury (inHg) pressure—defines the atmospheric context for this chart's data.

At this altitude and barometric pressure, the air's properties (like density and enthalpy) differ from standard sea-level conditions. Engineers use such altitude-specific charts for accurate HVAC system design, sizing equipment like cooling towers and air handlers, and predicting dew points for applications in aerospace, mining, or high-altitude construction.

The chart's enthalpy values, given in BTU per pound of dry air, are critical for calculating total heating or cooling loads. By locating the intersection of dry-bulb temperature and another parameter (like wet-bulb temperature or relative humidity) on this chart, you can directly read all other psychrometric properties without complex calculations.

References

• Original Source