1. What is the Evaporation Rate Equation?

The evaporation rate equation calculates how quickly water evaporates from a surface based on air velocity, surface area, and humidity differences. It's commonly used in industrial, environmental, and HVAC applications.

2. How Does the Calculator Work?

The calculator uses the evaporation rate equation:

Where:

• \( v \) — Air velocity (m/s)
• \( A \) — Surface area (m²)
• \( X_s \) — Saturation humidity (kg/kg)
• \( X \) — Air humidity (kg/kg)

Explanation: The equation accounts for both natural convection (25 term) and forced convection (19v term) effects on evaporation.

3. Importance of Evaporation Rate Calculation

Details: Accurate evaporation rate estimation is crucial for designing cooling systems, predicting water loss in reservoirs, and controlling industrial drying processes.

4. Using the Calculator

Tips: Enter air velocity in m/s, surface area in m², and humidity values in kg/kg. All values must be valid (area > 0, Xₛ ≥ X).

5. Frequently Asked Questions (FAQ)

Q1: What are typical values for saturation humidity?
A: At 20°C, Xₛ ≈ 0.0147 kg/kg; at 30°C, Xₛ ≈ 0.0272 kg/kg. Values increase exponentially with temperature.

Q2: How does air velocity affect evaporation?
A: Higher velocities increase evaporation by removing moist air from the surface and bringing in drier air.

Q3: What's a typical evaporation rate for a swimming pool?
A: About 0.1-0.3 kg/h/m² in calm conditions, increasing to 1-3 kg/h/m² with moderate wind.

Q4: Are there limitations to this equation?
A: The equation assumes constant conditions and may not account for temperature variations or complex geometries.

Q5: How can I reduce evaporation in my application?
A: Reduce air velocity, increase humidity, or use surface covers to minimize evaporation.