How is water catchment area calculated?

Catchment volume = roof area × rainfall × collection efficiency (0.85-0.95). Earthships use 4-pass internal water recycling to reduce total demand by 70%.

How much roof area is needed for water self-sufficiency?

A family of 4 using 50 gallons/day needs roughly 2,000-5,000 sqft of catchment area depending on local annual rainfall.

Earthship Water Catchment Sizing Calculator

Formula Definitions

The Earthship Water Catchment Sizing Calculator works by applying a well-defined formula to the values you enter. Understanding the formula behind the calculation helps you interpret the result and check that your inputs are correct. Below we break down the key components that drive the Earthship Water Sizing.

The core formula used by this calculator is:

Result = f(inputs, settings)

Each variable in the formula has a specific meaning:

inputs — Values entered into the Earthship Water Sizing.
settings — Options, units, or parameters that adjust how the calculation is performed.
Result — Computed output for the chosen inputs and settings.

How to Use This Calculator

Enter the required values. Enter the required values into the Earthship Water Catchment Sizing Calculator input fields.
Adjust settings. Adjust any settings, select applicable options, or choose units as needed.
Calculate the result. Press Calculate to compute the result using the underlying formula.
Interpret the output. Review and interpret your result using the provided context, reference ranges, or explanatory notes.

Glossary and Definitions

Input: A value entered into the calculator to be processed.
Output: The computed result returned by the calculator for the given inputs.
Setting: An option that adjusts how the calculation is performed, such as unit selection or mode.
Earthship water catchment: A key concept referenced by the Earthship Water Sizing: Size the water catchment and cistern system for an Earthship or off-grid home. Calculate roof collection area, cistern volume, greywater recycling passes, and water self-sufficiency percentage based on local rainfall data.
Rainwater collection sizing: A key concept referenced by the Earthship Water Sizing: Size the water catchment and cistern system for an Earthship or off-grid home. Calculate roof collection area, cistern volume, greywater recycling passes, and water self-sufficiency percentage based on local rainfall data.
Off-grid water system: A key concept referenced by the Earthship Water Sizing: Size the water catchment and cistern system for an Earthship or off-grid home. Calculate roof collection area, cistern volume, greywater recycling passes, and water self-sufficiency percentage based on local rainfall data.
Cistern sizing calculator: A key concept referenced by the Earthship Water Sizing: Size the water catchment and cistern system for an Earthship or off-grid home. Calculate roof collection area, cistern volume, greywater recycling passes, and water self-sufficiency percentage based on local rainfall data.

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