Technical Manual · Fire Commissioning
Fire Safety Checklist — Methodology & Commissioning Basis
Every input, formula, constant, band, and output behind the DC fire-safety commissioning and inspection checklist — from the clean-agent design acceptance bands (NFPA 2001) and detection parameters to the NFPA 855 Li-ion fire-watch requirements, the checklist score equation, and the cartridge recharge scheduler. All constants are sourced from js/fire-model.js (FIRE_MODEL, deep-frozen). Distinct from the suppression-sizing calculator (manual/fire.html) and the P&ID cockpit (manual/fire-system.html) — this page documents the commissioning and inspection checklist logic.
01 Purpose & engineering basis
The fire-safety checklist serves two distinct but overlapping use cases: commissioning sign-off (first-time acceptance of a new or upgraded clean-agent suppression system) and routine inspection (periodic verification that the installed system still meets its design basis). It is a companion to the suppression-sizing calculator methodology — the calculator produces the design quantity (agent mass W, cylinders, detectors); this checklist verifies that the installed system matches the design and continues to operate within the acceptance bands.
The governing basis is NFPA 2001 (2022) for clean-agent systems (design concentrations, discharge time, hold time, cartridge recharge), NFPA 72 for detection and alarm, and NFPA 855 (2023) for Li-ion battery-room off-gas detection and fire-watch obligations. Constants in the checklist are locked in FIRE_MODEL.bands and FIRE_MODEL.agents — no user-editable tolerance overrides.
02 Inputs
Six inputs drive the checklist engine. Date inputs feed the recharge countdown; toggle groups select which checklist sections apply to the zone being inspected.
| Field | Symbol / key | Unit / type | Default | Meaning |
|---|---|---|---|---|
Hall volume inVol | V | m³ | 500 | Net protected volume; used to cross-check agent intensity (kg/m³) against design. |
System tier inTier | — | enum | T3 | Tier I–IV. Affects redundancy expectations for cross-zone detection; cosmetic label only in score. |
Cartridge last fill date inFillDate | D_fill | ISO date | today | Date of last full cylinder recharge. Drives the 5-year recharge countdown. |
Last inspection date inInspDate | D_insp | ISO date | today | Date of last annual inspection. Flags overdue annual review. |
Clean-agent zone present chkAgent | — | boolean toggle | true | Includes clean-agent design-band items (concentrations, discharge, hold) in the score. |
Li-ion battery room present chkLiIon | — | boolean toggle | false | Includes NFPA 855 Li-ion off-gas detection, fire-watch, and ventilation items in the score. |
03 Calculation methodology
Three independent sub-computations: the checklist score percentage, the cartridge recharge countdown, and the design-band pass/fail flags. All reference the same frozen FIRE_MODEL constants used by the suppression calculator.
Checklist score
items_passed = count of toggled checklist items whose field value meets the acceptance criterion.
total_items = all toggled items (sections enabled by chkAgent / chkLiIon).
Commissioning sign-off requires score% = 100; routine inspection pass requires score% ≥ 80
AND all safety-critical items individually green (NOAEL margin, discharge time, hold time, H₂/CO detection status).
FIRE_MODEL · DERIVED
Cartridge recharge countdown
FIRE_MODEL.bands.rechargeIntervalYr = 5.
Additionally, cylinder weight must be verified annually; any loss > 5% of design charge triggers immediate recharge regardless of calendar date.
NFPA 2001 · STANDARD
Clean-agent design band checks (inline FIRE_MODEL)
FIRE_MODEL — never hardcoded in the checklist page.
Novec 1230 NOAEL = 10.0%; FM-200 NOAEL = 9.0%; IG-541 NOAEL = 43%.
NFPA 2001 / NFPA 72 · STANDARD
NFPA 855 Li-ion off-gas detection band
FIRE_MODEL.offGas.ventGasLflPct = 6.0, h2LflPct = 4.0, coLflPct = 12.5.
Fire-watch obligation: NFPA 855 §15 requires continuous fire-watch during any outage of the primary combustible-gas detection system in a Li-ion battery room.
NFPA 855 / UL 9540A · STANDARD
04 Constants & data sources
All constants live in FIRE_MODEL (deep-frozen, zero-build). The checklist reads them at runtime — never duplicates them. Key design bands:
| Constant | Value | FIRE_MODEL key | Source |
|---|---|---|---|
| Halocarbon discharge time (max) | 10 s | bands.dischargeTimeS.max | NFPA 2001 |
| Inert-gas discharge time (max) | 60 s | — | NFPA 2001 |
| Concentration hold time (min) | 10 min | bands.holdTimeMin.min | NFPA 2001 |
| Spot-detector coverage area (max) | 84 m² | bands.spotDetectorAreaM2.max | NFPA 72 (~9.1 m spacing) |
| Gas-detect alarm setpoint (max) | 25% LFL | bands.gasDetectAlarmPctLfl.max | NFPA 855 |
| Battery-room temperature (band) | 15–27 °C | bands.batteryRoomTempC | ILLUSTRATIVE / thermal mgmt |
| Cartridge recharge interval | 5 years | bands.rechargeIntervalYr | NFPA 2001 |
| Vent-gas governing LFL | 6.0 vol% | offGas.ventGasLflPct | NFPA 855 / UL 9540A |
| H₂ lower flammable limit | 4.0 vol% | offGas.h2LflPct | NFPA 855 |
| Agent | Class-A C% | Min extinguish% | NOAEL% | LOAEL% | GWP₁₀₀ |
|---|---|---|---|---|---|
| Novec 1230 (FK-5-1-12) | 4.7 | 3.5 | 10.0 | 10.0 | 1 |
| FM-200 (HFC-227ea) | 7.0 | 5.8 | 9.0 | 10.5 | 3 220 |
| IG-541 (Inergen) | 37.5 | 34.2 | 43 | 52 | 0 |
| Li-ion chemistry | Runaway onset (°C) | Off-gas (L/Wh) | TR heat factor | Basis tag |
|---|---|---|---|---|
| NMC | 150 | 4.0 | 2.5 | STANDARD |
| LFP | 166.8 | 2.0 | 1.2 | STANDARD |
| LCO | 150 | 4.5 | 2.6 | ILLUSTRATIVE |
| VRLA (lead-acid) | — | 0 | 0 | STANDARD |
05 Outputs
Five output channels, each readable as a pass/fail flag or a numeric value for the service record.
| Output | Formula / source | Unit | Pass criterion |
|---|---|---|---|
| Checklist score | items_passed / total × 100 | % | 100% (commissioning); ≥80% (routine) with all critical items green. |
| Recharge countdown | (D_fill + 5 yr) − today | days / months | > 6 months remaining = OK; ≤ 6 months = DUE SOON; ≤ 0 = OVERDUE. |
| Design-band pass/fail flags | discharge, hold, NOAEL, detector count | boolean × 4 | All four green; any red = safety-critical fail regardless of score. |
| NFPA 855 fire-watch flag | gas detection online/offline status | boolean | Green if H₂/CO detection active and calibrated; fire-watch required if red. |
| Certificate readiness | score = 100 AND all flags green AND recharge OK | boolean | True = ready for commissioning certificate; false = deficiencies listed. |
06 Worked example
A 500 m³ Tier III data hall with Novec 1230 at 4.7%, floor area 170 m², cartridge filled 2022-01-15, last inspection 2024-06-01, no Li-ion battery room.
- Design-band check — discharge: halocarbon band max = 10 s. Installed system discharge time (from commissioning record) = 8 s → PASS
- Design-band check — hold time: door-fan test measured hold = 13 min ≥ 10 min → PASS
- Design-band check — NOAEL margin: Novec 1230 design C = 4.7%, NOAEL = 10.0%; margin =
10.0 − 4.7 =5.3 pts → PASS (occupiable) - Design-band check — spot detectors: required =
ceil(170 / 84) =3; installed = 4 → PASS - Recharge countdown: D_fill = 2022-01-15; 5-year expiry = 2027-01-15; today (inspection date, example 2026-07-20); daysRemaining = 179 days → DUE SOON (within 6 months) — flag for recharge scheduling.
- Annual inspection overdue check: D_insp = 2024-06-01; elapsed = ~25 months > 12 → OVERDUE — annual inspection required
- Checklist score (example run with 20 of 23 items toggled, 18 passed):
18 / 20 × 100 =90% → routine inspection PASS threshold (≥80%) met, but recharge and inspection-cadence deficiencies must be noted. - Certificate readiness: score < 100% and recharge DUE SOON → NOT READY for commissioning certificate. Deficiencies: recharge, annual inspection, 2 open checklist items.
0.25 × 6.0 vol% = 1.5 vol%. If the sensor is offline for maintenance, NFPA 855 requires a continuous fire-watch at all times during the outage — the checklist flags this automatically when the Li-ion toggle is enabled and the gas-detection status is set to "offline".07 References & standards
- NFPA 2001 (2022) — Clean Agent Fire Extinguishing Systems: design concentrations, NOAEL/LOAEL, discharge ≤ 10 s (halocarbon) / ≤ 60 s (inert), hold time ≥ 10 min, annual cylinder inspection, 5-year recharge interval, k1/k2 mass-equation coefficients.
- NFPA 72 — National Fire Alarm & Signaling Code: spot-detector coverage (~84 m², 9.1 m spacing), cross-zone release logic, pre-discharge alarm, FACP function-test cadence.
- NFPA 855 (2023) — Stationary Energy Storage Systems: combustible-gas (H₂/CO) detection at ≤ 25% LFL, fire-watch during detection-system outage, ventilation sizing, compartmentation, BMS–FACP coordination, unit-spacing per UL 9540A test results.
- UL 9540A:2024 — ESS Thermal-Runaway Fire-Propagation Test: off-gas volume basis per chemistry, spacing validation methodology.
- ISO 14520 / FM Global DS 5-32 — Gaseous suppression system installation and data-center fire protection.
- NFPA 70 (NEC) Art. 645 — IT room EPO, interlocks with suppression release.
- ASHRAE 62.1 — Ventilation for Acceptable Indoor Air Quality: minimum ventilation rates referenced by battery-room exhaust sizing.
- Model source —
js/fire-model.js(FIRE_MODEL v1.0.0, deep-frozen) — single source of all constants used by the checklist and the suppression calculator.
08 Assumptions & limitations
The checklist assumes a total-flooding clean-agent system in a well-sealed enclosure (verified by door-fan test). Cylinder-fill capacity figures in the underlying FIRE_MODEL are tagged ILLUSTRATIVE and must be confirmed against the selected manufacturer's cylinder data sheet before use in contract documents. The 5-year recharge interval is a maximum; vendor requirements, AHJ mandate, or measured weight loss > 5% may shorten it. The Li-ion off-gas volume (L/Wh) in FIRE_MODEL is a screening estimate based on published UL 9540A test literature — it is not a substitute for a full UL 9540A test report on the specific ESS make and model installed. The fire-watch requirement applies whenever primary off-gas detection is unavailable, regardless of the checklist score. This methodology page and the associated checklist are an engineering education and commissioning preparation aid; final acceptance must be signed off by a qualified fire-protection engineer licensed to the authority having jurisdiction.