Water Tank Sizing Calculator

Water Tank Sizing Formula:

\[ V = A \times R \times 0.9 \]

Tank Volume (V):

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1. What is Water Tank Sizing?

Water tank sizing is the process of determining the appropriate capacity for a rainwater harvesting system based on catchment area and rainfall patterns. Proper sizing ensures adequate water storage for intended uses while optimizing system efficiency.

2. How Does the Calculator Work?

The calculator uses the water tank sizing formula:

\[ V = A \times R \times 0.9 \]

Where:

\( V \) — Tank volume (liters)
\( A \) — Catchment area (m²)
\( R \) — Rainfall (mm)
0.9 — Efficiency factor accounting for system losses

Explanation: The formula calculates the theoretical maximum rainwater collection volume, adjusted for typical system efficiency losses of approximately 10%.

3. Importance of Proper Tank Sizing

Details: Correct tank sizing is essential for maximizing water savings, ensuring reliable supply during dry periods, optimizing investment costs, and preventing overflow or underutilization of the rainwater harvesting system.

4. Using the Calculator

Tips: Enter catchment area in square meters and rainfall in millimeters. Both values must be positive numbers. The calculator provides the recommended tank volume in liters.

5. Frequently Asked Questions (FAQ)

Q1: Why is there a 0.9 efficiency factor?
A: The 0.9 factor accounts for typical system losses including first flush diversion, evaporation, splash loss, and filtration inefficiencies.

Q2: What catchment areas can be used?
A: Typically roof surfaces (tiled, metal, concrete), but also paved areas and other impervious surfaces that direct water to the collection system.

Q3: How do I determine rainfall data?
A: Use local meteorological data, annual rainfall averages for your region, or consult rainfall maps specific to your location.

Q4: Should I consider water usage patterns?
A: Yes, for optimal sizing also consider daily water demand, dry period duration, and intended uses (gardening, toilet flushing, etc.).

Q5: Are there minimum/maximum practical tank sizes?
A: Yes, very small tanks may not be cost-effective, while very large tanks require significant space and investment. Most residential systems range from 1,000 to 20,000 liters.