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Relative Humidity Formula:
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Relative humidity (RH) is the ratio of the current amount of water vapor in the air to the maximum amount the air could hold at that temperature, expressed as a percentage. It's a crucial parameter in meteorology, HVAC, and various industrial processes.
The calculator uses the relative humidity formula:
Where:
Explanation: The formula calculates what percentage the actual vapor pressure is of the maximum possible vapor pressure at that temperature.
Details: Accurate relative humidity measurement is essential for weather forecasting, climate control systems, agricultural practices, industrial processes, and maintaining comfortable and healthy indoor environments.
Tips: Enter both actual vapor pressure and saturation vapor pressure in hPa. Values must be valid (both > 0, and e ≤ e_s).
Q1: What is the difference between absolute and relative humidity?
A: Absolute humidity measures the actual amount of water vapor in the air (g/m³), while relative humidity expresses this as a percentage of the maximum possible at that temperature.
Q2: What are typical relative humidity ranges?
A: Comfortable indoor RH is typically 30-50%. Below 30% can cause dryness issues, while above 60% can promote mold growth.
Q3: How does temperature affect relative humidity?
A: Warmer air can hold more moisture, so relative humidity decreases as temperature increases if moisture content remains constant.
Q4: How is saturation vapor pressure determined?
A: Saturation vapor pressure depends primarily on temperature and can be calculated using various empirical formulas like the Magnus formula.
Q5: Why is relative humidity important in weather forecasting?
A: RH helps predict precipitation, fog formation, and is a key factor in heat index calculations that determine apparent temperature.