With no air movement in a room ____________ can possibly occur?

• A. Stratification
• B. Convection
• C. Drafts
• D. Mixing

Answer: (A)

When there is no air movement, stratification can occur. In a still room, heat from sources rises, so warmer air tends to accumulate up near the ceiling while cooler, denser air stays toward the floor. Without any mixing—no fans, diffusers, or drafts—the vertical temperature difference remains, forming distinct layers of air at different temperatures. Convection, drafts, and mixing all rely on some air movement, so they are unlikely in a still room, whereas stratification is the natural result of stagnant air with buoyancy-driven layering.