Dew Point Calculator

Dew Point Equation:

\[ T_{dp} = \frac{243.04 \times \ln(e / 6.112)}{17.625 - \ln(e / 6.112)} \]

Dew Point (T_dp):

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1. What is Dew Point?

The dew point (T_dp) is the temperature at which air becomes saturated with water vapor and dew begins to form. It's a measure of atmospheric moisture.

2. How Does the Calculator Work?

The calculator uses the dew point equation:

\[ T_{dp} = \frac{243.04 \times \ln(e / 6.112)}{17.625 - \ln(e / 6.112)} \]

Where:

\( T_{dp} \) — Dew point temperature (°C)
\( e \) — Vapor pressure (hPa)
6.112 — Reference vapor pressure (hPa) at 0°C
17.625, 243.04 — Empirical constants for water

Explanation: The equation relates vapor pressure to the temperature at which condensation occurs.

3. Importance of Dew Point Calculation

Details: Dew point is crucial in meteorology, HVAC design, industrial processes, and predicting fog or frost formation.

4. Using the Calculator

Tips: Enter vapor pressure in hPa (hectopascals). The value must be greater than 0.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between dew point and humidity?
A: While relative humidity depends on temperature, dew point is an absolute measure of moisture in the air.

Q2: What does a high dew point indicate?
A: Higher dew points mean more moisture in the air, leading to muggy conditions. Above 20°C is uncomfortable for most people.

Q3: Can dew point be higher than air temperature?
A: No, this would require supersaturation which is unstable in nature. The dew point is always ≤ current temperature.

Q4: How is vapor pressure measured?
A: It can be calculated from relative humidity and temperature or measured directly with specialized instruments.

Q5: What's the relationship between dew point and frost point?
A: Frost point is the dew point when below freezing. The equations differ slightly for ice vs liquid water.