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Water Vapor Pressure Formula:
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Water vapor pressure is the partial pressure of water vapor in any gas mixture in equilibrium with solid or liquid water. It represents the contribution of water vapor to the total atmospheric pressure and is a key parameter in meteorology and HVAC applications.
The calculator uses the water vapor pressure formula:
Where:
Explanation: The formula calculates the actual vapor pressure by multiplying the saturation vapor pressure by the relative humidity expressed as a decimal fraction.
Details: Water vapor pressure is crucial for understanding humidity levels, predicting weather patterns, designing HVAC systems, and various industrial processes where moisture control is important.
Tips: Enter relative humidity as a percentage (0-100%) and saturation vapor pressure in hPa. Both values must be valid (RH between 0-100, e_s > 0).
Q1: What is saturation vapor pressure?
A: Saturation vapor pressure is the maximum vapor pressure that can exist at a given temperature, representing the point where air is fully saturated with water vapor.
Q2: How does temperature affect water vapor pressure?
A: Saturation vapor pressure increases exponentially with temperature, meaning warmer air can hold more water vapor than cooler air.
Q3: What are typical values for water vapor pressure?
A: In Earth's atmosphere, water vapor pressure typically ranges from 0 hPa in dry conditions to about 40 hPa in very humid tropical conditions.
Q4: How is this different from absolute humidity?
A: Water vapor pressure is a measure of the partial pressure of water vapor, while absolute humidity is the mass of water vapor per volume of air.
Q5: Why is water vapor pressure important in meteorology?
A: It's a key parameter for calculating dew point, relative humidity, and for understanding atmospheric stability and precipitation processes.