What is the required water supply duration for commercial systems according to NFPA 13?

The required water supply duration for commercial systems according to NFPA 13 is indeed set at 30 minutes. This duration is specified to provide adequate coverage for a variety of fire scenarios that can occur within commercial settings. NFPA 13 emphasizes the need for a water supply that is not only sufficient in volume but also capable of maintaining pressure during that critical initial response period, which is often the first half-hour of an event.

This duration is designed to ensure that the sprinkler systems have enough time to effectively control and possibly extinguish a fire before other emergency interventions, like fire department arrival, can take over. The 30-minute requirement reflects a balance between operational necessity and economic considerations for businesses during system design and installation.