Which weather-sealing factor is linked to reducing stack effect in multi-story buildings?

Which weather-sealing factor is linked to reducing stack effect in multi-story buildings?

• A. Stairwell fire doors
• B. Basement windows
• C. Rooftop vents
• D. Elevator doors

Answer: (A)

Stack effect occurs when warm indoor air rises and moves upward through a building, creating pressure differences that pull cooler air in at lower levels and push air out at higher levels. The weather-sealing factor that most effectively reduces this is sealing the stairwell doors, especially the fire doors. When these doors are well-sealed, air can’t easily leak in or out of the stairwell as pressure builds, which cuts down the driving force behind the vertical air movement. This helps keep temperatures and drafts more stable between floors and also improves smoke control in a fire scenario by limiting a vertical air corridor. Basement windows are below the main circulation path and, while sealing any opening helps overall leakage, they’re not the primary route for stack-driven air movement in a multi-story building. Rooftop vents can actually facilitate stack effect by letting warm air escape to the exterior. Elevator doors can leak, but they aren’t the main factor linked to reducing stack effect the way sealing stairwell doors is.

Stack effect occurs when warm indoor air rises and moves upward through a building, creating pressure differences that pull cooler air in at lower levels and push air out at higher levels. The weather-sealing factor that most effectively reduces this is sealing the stairwell doors, especially the fire doors. When these doors are well-sealed, air can’t easily leak in or out of the stairwell as pressure builds, which cuts down the driving force behind the vertical air movement. This helps keep temperatures and drafts more stable between floors and also improves smoke control in a fire scenario by limiting a vertical air corridor.

Basement windows are below the main circulation path and, while sealing any opening helps overall leakage, they’re not the primary route for stack-driven air movement in a multi-story building. Rooftop vents can actually facilitate stack effect by letting warm air escape to the exterior. Elevator doors can leak, but they aren’t the main factor linked to reducing stack effect the way sealing stairwell doors is.