Calculator Inputs
Use consistent units. Results reflect simplified geometric coverage.
Example Data Table
Use these examples to verify your inputs and expectations.
| Scenario | Area | Hose | Allowance | Height | Obstruction | Overlap | Estimated reels |
|---|---|---|---|---|---|---|---|
| Warehouse bay | 1,200 m² | 30 m | 2 m | 1.5 m | 80% | 10% | 1 |
| Plant room | 250 m² | 25 m | 3 m | 1.2 m | 70% | 15% | 1 |
| Office floor | 1,800 m² | 30 m | 2 m | 1.5 m | 65% | 10% | 2 |
Examples are illustrative. Always follow local codes and authority requirements.
Formula Used
This calculator uses simple geometry with adjustment factors.
1) Effective hose length
Le = Lhose − Lallowance
2) Horizontal reach (height adjustment)
Rh = √(Le² − Houtlet²) (if Le > Houtlet)
3) Adjusted coverage radius (obstructions)
R = Rh × (Obstruction% / 100)
4) Coverage area per reel
Areel = π × R²
5) Design area (overlap / redundancy)
Adesign = Afloor × (1 + Overlap% / 100)
6) Required reels
Nrequired = ceil(Adesign / Areel)
This approach estimates coverage area only. Layout, corridor routing, and compartmentation can require additional reels.
How to Use This Calculator
A practical workflow for early design and checks.
- Select units, then enter hose length and allowance.
- Enter outlet height and an obstruction factor.
- Enter overlap to add redundancy margin.
- Provide floor area, or enter length and width.
- Optionally enter installed reels for surplus/deficit.
- Calculate, then export CSV or PDF if needed.