# WaterPod rainwater calculations

The WaterPod will be collecting rainwater from a few of the impermeable roof areas. The calculations for collection are on this spreadsheet. There are three tabs feeding the results:

- Tab:Collection Calcs - Calculates the monthly availability of the rainwater.
- Tab:Collections Dimensions - Calculates the available rainwater collection area based upon the planned structures.
- Tab:Regional Climate Data - Show monthly rainfall from historical averages. Could be made more current.

## Regional Climate Data[edit | edit source]

The historical 1971 - 2000 Rainfall Normals for Central Park, New York[1] are:

Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |

3.42 | 3.27 | 4.08 | 4.2 | 4.42 | 3.67 | 4.35 | 4.01 | 3.89 | 3.56 | 4.47 | 3.91 | 47.25 |

## Basic Calculation[edit | edit source]

[math] Collection\ Volume (gal) = Rainfall\ (in) \times \frac{1 ft}{12 in}\times Collection\ Area\ (ft^2) \times \frac{7.48 gal}{ft^3} \times Roof\ Coefficient \times Efficiency[/math]

or

[math] V=R \times A\times k \times e[/math]

(in some cases the efficiency of the system is assumed to be 100% and therefore equal to 1, having no effect on the rest of the equation.)

Click here for more detailed rainwater collection calculations and explanations.

## Conclusion[edit | edit source]

Wait until the spreadsheet is finalized before posting the final conclusions here.