1. What is the Rainwater Collection Formula?

The rainwater collection formula calculates the potential volume of rainwater that can be harvested from a roof surface. It considers the roof area, rainfall amount, and collection efficiency to estimate usable water volume.

2. How Does the Calculator Work?

The calculator uses the rainwater collection formula:

Where:

• \( Roof Area \) — Surface area of the roof (m²)
• \( Rainfall \) — Amount of rainfall (mm)
• \( Efficiency \) — Collection efficiency percentage (%)

Explanation: The formula converts rainfall from mm to meters (dividing by 1000) and applies the efficiency factor to account for system losses.

3. Importance of Rainwater Calculation

Details: Accurate rainwater calculation helps in designing appropriate storage systems, estimating water supply potential, and promoting sustainable water management practices.

4. Using the Calculator

Tips: Enter roof area in square meters, rainfall in millimeters, and efficiency as a percentage. All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical efficiency value for rainwater collection?
A: Efficiency typically ranges from 70-90%, depending on roof material, gutter system, and filtration efficiency.

Q2: Why convert rainfall from mm to meters?
A: 1 mm of rain equals 1 liter per square meter, so dividing by 1000 converts to cubic meters (1 m³ = 1000 liters).

Q3: Does roof slope affect collection efficiency?
A: Yes, steeper roofs may have slightly higher efficiency due to faster water runoff and reduced evaporation.

Q4: What factors reduce collection efficiency?
A: Evaporation, splash loss, first-flush diversion, gutter overflow, and filtration losses can reduce efficiency.

Q5: Can this calculator be used for commercial buildings?
A: Yes, the same formula applies to any roof surface, though efficiency factors may vary based on system design.