This spreadsheet is an engineering tool designed for the hydraulic analysis of roof drainage systems. Its primary function is to determine if a proposed drainage pipe has adequate capacity to handle the expected rainwater runoff from a specific roof area.
The calculations performed by this tool are based on the principles outlined in the European standardEN 12056-3:2000, which pertains to gravity drainage systems inside buildings.
Key Features and Calculation Process:
- Input Parameters: The user must provide key project-specific data, including:
- Effective Catchment Area (A): The total roof area that collects rainwater.
- Local Rainfall Intensity (r): The design rainfall rate for the building’s location.
- Internal Pipe Diameter (D): The size of the drainage pipe being evaluated.
- Pipe Slope (S): The gradient at which the pipe is installed.
- Manning’s Roughness (n): A coefficient that represents the friction of the pipe material.
- Automatic Calculations: Based on the inputs, the sheet automatically calculates three critical values:
- Required Flowrate (Q_req): The volume of water per second that the system must handle, calculated from the catchment area and rainfall intensity.
- Pipe Capacity (Q_pipe): The maximum flowrate the specified pipe can handle, calculated using the Manning’s equation based on its diameter, slope, and roughness.
- Flow Velocity (v): The speed of the water within the pipe.
Multilingual Support: The spreadsheet is designed for international use, featuring a language selection dropdown that translates the labels for user convenience. ( Francais , Germany )