Data center fire protection is defined by a single constraint: the equipment being protected is worth far more than the building, it cannot tolerate residue of any kind, and the business consequence of an outage frequently exceeds the fire damage itself. That combination is why clean agent became the standard rather than water or chemical suppression, and why NFPA 75 addresses room construction and materials as thoroughly as it addresses suppression.
The fires themselves are usually small. Overheating power supplies, failing capacitors, and cable insulation faults produce smoke and localized burning long before they produce a structurally significant fire, which is why very early smoke detection is central to the strategy. Aspirating detection can identify combustion products at concentrations far below conventional spot detector thresholds, frequently while the failure is still an unusual smell rather than a visible event.
Where these installations actually fail is hold time. Clean agent extinguishes by achieving a design concentration and maintaining it long enough for the fuel to cool below reignition temperature. The agent quantity is calculated for a specific room volume and leakage rate, and if the room leaks faster than the design assumed, the concentration falls below effectiveness before the hold time expires and the fire reignites. Data centers are among the worst offenders because they accumulate cable penetrations continuously as they grow.