| Scenario | Room (L×W×H) | Agent | Design conc. | Temp | Elevation | Safety | Result (kg) | Cyl (45 kg @0.95) |
|---|---|---|---|---|---|---|---|---|
| Server room | 6×4×3 m | Novec 1230 | 5.3% | 20C | 0 m | 15% | ~65–85 | 2 |
| MCC room | 8×5×3 m | FM-200 | 7.0% | 25C | 500 m | 20% | ~110–150 | 3–4 |
| Battery room | 5×3×3 m | IG-541 | 40% | 20C | 0 m | 10% | High-pressure system | Per vendor |
- Measure the protected enclosure inside length, width, and average height.
- Select the agent type, then enter the design concentration from your hazard class and manufacturer guidance.
- Enter temperature and elevation to refine pressure-based mass estimation.
- Add reserve and safety factor for leakage, tolerances, and commissioning allowances.
- Enter cylinder capacity and fill efficiency to estimate cylinder count.
- Click Calculate, review results, then export CSV/PDF for documentation.
Protected volume and enclosure assumptions
Flooding systems scale directly with enclosure volume, so accurate measurements matter. Include raised floors, ceiling voids, and equipment cabinets only when the agent will reach them. If the space has large openings, add reserve or improve integrity before relying on calculated mass.
Design concentration selection and safety limits
Design concentration depends on fuel type, ventilation, and safety criteria. Clean agents for occupied spaces typically use single-digit percentages, while inert gases can require much higher fractions. Always verify exposure limits, signage, alarms, and discharge delays for the selected agent.
Pressure, temperature, and elevation effects
At higher elevation, ambient pressure drops and fewer air moles exist in the same volume, changing the agent mass required to reach a given fraction. Temperature also affects molar quantity. This tool estimates pressure from elevation and applies ideal-gas relationships to produce a consistent screening value.
Allowances, reserve, and cylinder utilization
Real installations need allowances for leakage, agent retention, piping losses, and manufacturing tolerances. Reserve adds extra agent before the safety factor. Cylinder utilization accounts for non-usable charge due to residuals or specification limits. Round cylinder counts up to reduce under-sizing risk.
Documentation, exports, and commissioning checks
Use the CSV export for submittal spreadsheets and the PDF export for field packages. Commissioning should include enclosure integrity testing, pressure relief sizing, nozzle coverage verification, and confirmation that the agent concentration meets the hazard and occupancy requirements. Treat this calculator as an early design and review aid.
Include the hazard description, occupancy classification, and the chosen design concentration basis in your submittal. Record room dimensions, assumed temperature, and elevation so reviewers can reproduce the calculation. If pressure relief is required, document vent area, setpoint, and discharge duration. During commissioning, verify cylinder weights, nozzle orientation, and actuation sequence, then run a functional test of alarms and shutdowns. Update the exported files when field changes occur to keep as-built records consistent. Also note pre-discharge time delay, manual abort location, and any ventilation interlocks tied to equipment.
1) Is this a final design tool?
No. It provides a screening estimate using ideal-gas relationships. Final design needs manufacturer software or tables, nozzle hydraulics, venting checks, and compliance with applicable fire suppression standards.
2) What concentration should I enter?
Use the concentration recommended for your hazard class and agent manufacturer. If unsure, start with the default and replace it once you confirm the required design concentration and exposure limits.
3) Why does elevation change the result?
Elevation affects ambient pressure. Lower pressure means fewer initial air moles in the same room volume, altering the agent moles needed to reach a target fraction under the ideal-gas estimate.
4) What is fill efficiency?
It is the usable fraction of a cylinder’s nameplate charge after allowances. It helps prevent overestimating deliverable agent when sizing cylinder quantity for procurement and documentation.
5) Can I use this for inert gas systems?
You can estimate mass, but inert gas systems are strongly dependent on cylinder pressure, storage configuration, and flow rates. Always confirm results using the supplier’s engineered design approach.
6) What should I export and keep for records?
Export CSV for calculations and assumptions, and PDF for field and review packages. Keep the input values, agent selection, concentration basis, and safety factors with the project file.