Boiling Points Water Altitude

Overview

Engineering reference data for Boiling Points Water Altitude in thermodynamics.

Key Formulas

First Law

$\Delta U = Q - W$

Energy is conserved — heat added minus work done.

Ideal Gas Law

$PV = nRT$

Relates pressure, volume, and temperature of an ideal gas.

Heat Transfer

$Q = mc\Delta T$

Sensible heat transfer.

Carnot Efficiency

$\eta = 1 - T_C/T_H$

Maximum efficiency between two temperatures.

Variables

References

• Original Source

Boiling Point vs Altitude Reference Table

Key Relationship

The decrease in boiling point with altitude follows from the barometric formula relating atmospheric pressure to altitude:

$P(h) = P_0 \cdot \exp\left(-\frac{Mgh}{RT}\right)$

where $P_0$ is sea-level pressure, $M$ is the molar mass of air, $g$ is gravitational acceleration, $R$ is the universal gas constant, $T$ is temperature, and $h$ is altitude.

The Clausius-Clapeyron equation then connects vapor pressure to temperature:

$\frac{dP}{dT} = \frac{L}{T \cdot \Delta v}$

where $L$ is the latent heat of vaporization and $\Delta v$ is the change in specific volume between liquid and vapor phases.

Practical Notes

• Rule of thumb: Boiling point decreases approximately 1°F (0.56°C) for every 500 ft (152 m) increase in altitude
• Cooking impact: At higher altitudes, longer cooking times are required since water boils at lower temperatures
• Pressure cookers: Counteract altitude effects by artificially increasing pressure above atmospheric