What is the water source for sprinkler system activation?

• A. Lavatory
• B. Automatic Water Supply
• C. System Riser
• D. Thermal Barrier

Answer: (B)

The water source for sprinkler activation is the Automatic Water Supply. In a low-rise residential system, water must be ready to flow into the sprinkler piping without manual intervention when a sprinkler head reaches its activation temperature. The automatic water supply provides that immediate source of water to the system so water can be delivered through the system riser to the sprinklers as soon as they are activated.

The lavatory is just a fixture for domestic use and does not feed the sprinkler network. The system riser is the vertical piping that carries water from the supply into the sprinkler system, but it isn’t the source itself. The thermal barrier relates to insulation and fire resistance, not to water supply. Hence, the automatic water supply is the correct concept for the water source.