Why we don't have certain fire suppression calcs

Clean agent volume — FM-200, Novec 1230, Halotron

Clean agent suppression systems have a very narrow concentration window: too low and the fire isn't extinguished; too high and you injure or kill occupants (FM-200 NOAEL is 9% — exceed 10.5% LOAEL and you risk cardiac sensitization).

Real design requires the manufacturer's UL-listed flow calc software (DSPA, Sevo Systems, Hygood). It accounts for room geometry, leakage rate, agent expansion, nozzle pressure curves, and pipe-network balancing.

Use: Sevo Systems hardware partner software, Kidde Fire Systems software, or hire a fire protection engineer (FPE) with manufacturer training.

CO2 flooding system design

High-pressure CO2 suppression floods a room at 34-75% concentration. That concentration kills humans — there have been multiple fatal accidents from misdesigned CO2 systems. Some involved technicians performing maintenance who weren't aware the system was charged.

CO2 systems are governed by NFPA 12, require pre-discharge alarms, ventilation interlocks, and very specific concentration calculations per hazard.

Use: Manufacturer's design software (Ansul, Fike) plus an FPE who's done CO2 systems before.

Dry chemical quantity (industrial systems)

Pre-engineered dry chemical systems (Class K, ABC, BC) are sized per the manufacturer's UL listing. Each nozzle has a specific coverage area + flow rate. Each agent type has a different application density. Mixing components from different manufacturers voids the listing entirely.

Use: The hardware manufacturer's design manual. Ansul R-102, Pyro-Chem PCL, Range Guard, etc.

Foam concentrate (AFFF, AR-AFFF)

Foam suppression for fuel spills involves: foam type selection (AFFF for hydrocarbons, AR-AFFF for polar solvents), application rate per NFPA 11, fuel type, container shape, expected drain rate, retention time. A misdesigned foam system can fail to suppress a tank fire entirely — and the consequence is a 10,000-gallon fuel fire that nothing on site can stop.

Use: NFPA 11 calculation worksheets, foam manufacturer technical bulletins, plus FPE review for any system protecting flammable liquid storage.

Halon replacement sizing

Halon 1301 is being phased out globally per the Montreal Protocol. Replacements (FK-5-1-12, IG-541 Inergen, etc.) have different concentration requirements and design rules than Halon. Cross-compatibility is not 1:1.

Use: A licensed FPE familiar with retrofit. Most replacements require new pipe networks and new nozzles, not just a new agent in old cylinders.

Ansul / wet chemical agent quantity (kitchen hoods)

UL 300 wet chemical hood suppression systems are sized exclusively per the manufacturer's listed flow chart. Ansul R-102, Pyro-Chem Kitchen Knight, Range Guard — each has specific nozzle-to-appliance pairings and tank-to-system flow requirements.

Using "estimated" agent quantity from a generic calculator voids the listing and may result in a kitchen fire that the suppression system can't extinguish. The cooking media reignites. People die from kitchen fires that "should" have been controlled.

Use: The manufacturer's design manual, performed by a licensed fire suppression contractor with that manufacturer's certification.

We do have planning-stage hood layout tools: Kitchen Hood Coverage and Duct Suppression Length. These give nozzle counts for planning — not final design.