Humidity From Wet Bulb Dry Bulb Calculator

Humidity Calculation Formula:

\[ RH = 100 \times \frac{\exp\left(\frac{17.625 \times (T_w - T_d)}{243.04 + T_w - T_d}\right)}{\exp\left(\frac{17.625 \times T_d}{243.04 + T_d}\right)} \]

Relative Humidity (RH):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What Is The Humidity From Wet Bulb Dry Bulb Calculation?

The humidity calculation from wet bulb and dry bulb temperatures is a method to determine relative humidity using psychrometric principles. It's based on the relationship between temperature differences and moisture content in the air.

2. How Does The Calculator Work?

The calculator uses the formula:

\[ RH = 100 \times \frac{\exp\left(\frac{17.625 \times (T_w - T_d)}{243.04 + T_w - T_d}\right)}{\exp\left(\frac{17.625 \times T_d}{243.04 + T_d}\right)} \]

Where:

\( T_w \) — Wet bulb temperature (°C)
\( T_d \) — Dry bulb temperature (°C)
\( \exp \) — Exponential function
17.625 and 243.04 — Constants for water vapor

Explanation: This formula calculates relative humidity by comparing the actual vapor pressure to the saturation vapor pressure at the dry bulb temperature.

3. Importance Of Humidity Calculation

Details: Accurate humidity measurement is essential for HVAC systems, meteorological forecasting, industrial processes, agricultural applications, and maintaining comfortable indoor environments.

4. Using The Calculator

Tips: Enter both wet bulb and dry bulb temperatures in Celsius. Ensure wet bulb temperature is equal to or less than dry bulb temperature for valid results.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between wet bulb and dry bulb temperatures?
A: Dry bulb temperature measures actual air temperature, while wet bulb temperature measures the lowest temperature achieved by evaporative cooling.

Q2: Why is wet bulb always lower than or equal to dry bulb temperature?
A: Evaporation from the wet bulb causes cooling, so it's typically lower except at 100% humidity when they're equal.

Q3: What are typical relative humidity ranges?
A: Comfortable indoor humidity is typically 30-60%. Below 30% may feel dry, above 60% can feel humid and promote mold growth.

Q4: How accurate is this calculation method?
A: This formula provides good estimates for standard atmospheric conditions but may have reduced accuracy at extreme temperatures or pressures.

Q5: Can this be used for Fahrenheit temperatures?
A: The formula requires Celsius inputs. Convert Fahrenheit to Celsius first using: °C = (°F - 32) × 5/9.