Home
Back
Water Vapor Pressure Formula:
| From: | To: |
The water vapor pressure formula calculates the partial pressure of water vapor in the air based on saturation vapor pressure and relative humidity. This is a fundamental calculation in meteorology, HVAC design, and environmental science.
The calculator uses the water vapor pressure formula:
Where:
Explanation: The formula calculates the actual vapor pressure by scaling the saturation vapor pressure (the maximum possible vapor pressure at a given temperature) by the relative humidity percentage.
Details: Water vapor pressure is crucial for understanding humidity levels, calculating dew point, predicting weather patterns, designing climate control systems, and assessing comfort conditions in indoor environments.
Tips: Enter saturation vapor pressure in Pascals (Pa) and relative humidity as a percentage (0-100%). Both values must be valid positive numbers.
Q1: What is saturation vapor pressure?
A: Saturation vapor pressure is the maximum pressure of water vapor that can exist in equilibrium with liquid water at a given temperature.
Q2: How is saturation vapor pressure determined?
A: Saturation vapor pressure depends primarily on temperature and can be calculated using various empirical formulas like the August-Roche-Magnus or Tetens equations.
Q3: What are typical values for water vapor pressure?
A: At room temperature (20°C), saturation vapor pressure is about 2330 Pa. Actual vapor pressure varies with humidity levels.
Q4: Why is water vapor pressure important in weather forecasting?
A: Water vapor pressure helps determine humidity levels, predict dew formation, and assess the potential for precipitation and cloud formation.
Q5: How does water vapor pressure relate to dew point?
A: Dew point is the temperature at which air becomes saturated (RH=100%) for a given vapor pressure. Higher vapor pressure corresponds to a higher dew point.