Buoyancy-driven ventilation increases with greater temperature difference, and increased height between the higher and lower apertures in the case of displacement ventilation. When both high and low level openings are present, the neutral plane in a building occurs at the location between the high and low openings at which the internal pressure will be the same as the external pressure (in the absence of wind).
Buoyancy-driven ventilation becomes more effective with greater temperature differences and higher vertical separation between high and low air inlets in displacement ventilation. The neutral plane in a building occurs at the location where the internal pressure matches the external pressure, assuming no wind effects.