Which system is intended to positively pressurize stair towers with outdoor air to keep smoke from contaminating the stair towers during an alarm condition?

Which system is intended to positively pressurize stair towers with outdoor air to keep smoke from contaminating the stair towers during an alarm condition?

• A. Smoke-Control System
• B. Pressure Zone System
• C. Stairwell Pressurization System
• D. Shaft Pressurization System

Answer: (C)

The main idea here is protecting the people using the stairs by keeping the stairwell clean of smoke during a fire. This is achieved by delivering outdoor air into the stair enclosure to create a positive pressure that prevents smoke from seeping in from adjacent spaces. Naming-wise, a system dedicated to this purpose is designed to supply outdoor air and maintain that positive pressure specifically in the stair towers, so the stairs remain tenable for evacuation and for firefighting operations. That’s why the stairwell pressurization system is the best fit. It is purpose-built to keep stair enclosures clear of smoke during an alarm condition by actively pressurizing them with outdoor air. The other options describe broader or different concepts: a general smoke-control system covers managing smoke spread in the building but not necessarily the targeted, outdoor-air pressurization of stair towers; a shaft pressurization system focuses on vertical shafts (like elevator or utility shafts) rather than the stair enclosure; a pressure zone system deals with maintaining designed pressures between zones, which isn’t specifically about keeping the stairwell pressurized with outdoor air during an alarm.

The main idea here is protecting the people using the stairs by keeping the stairwell clean of smoke during a fire. This is achieved by delivering outdoor air into the stair enclosure to create a positive pressure that prevents smoke from seeping in from adjacent spaces. Naming-wise, a system dedicated to this purpose is designed to supply outdoor air and maintain that positive pressure specifically in the stair towers, so the stairs remain tenable for evacuation and for firefighting operations.

That’s why the stairwell pressurization system is the best fit. It is purpose-built to keep stair enclosures clear of smoke during an alarm condition by actively pressurizing them with outdoor air. The other options describe broader or different concepts: a general smoke-control system covers managing smoke spread in the building but not necessarily the targeted, outdoor-air pressurization of stair towers; a shaft pressurization system focuses on vertical shafts (like elevator or utility shafts) rather than the stair enclosure; a pressure zone system deals with maintaining designed pressures between zones, which isn’t specifically about keeping the stairwell pressurized with outdoor air during an alarm.