Room air distribution describes the movement and mixing patterns of air within a space from supply outlets to exhaust returns. Effective room air distribution ensures uniform conditions throughout occupied zones while removing contaminants. Distribution patterns depend on supply velocity, outlet design, room geometry, and heat load distribution.
Distribution Strategies
Four primary distribution approaches include mixing ventilation (ceiling supplies with low velocity), displacement ventilation (low-level supplies with thermal stratification), task ventilation (localized delivery to occupied zones), and stratum ventilation (horizontal stratified layers). Mixing ventilation is most common in residential and office applications, providing comfort with 0.15-0.3 m/s air velocity at breathing height. Displacement ventilation achieves effectiveness indices of 1.2-1.5 by maintaining temperature stratification.
Design Considerations
Room air distribution design accounts for internal heat loads, occupancy patterns, and furniture placement. Supply registers should be positioned to avoid direct occupant exposure while ensuring adequate air circulation. Return inlets near exhaust-generating zones (kitchens, bathrooms) improve effectiveness by 15-30%. Ceiling height, insulation quality, and window thermal properties influence stratification and distribution. Proper air distribution design reduces energy consumption by 10-15% compared to poorly designed systems while eliminating comfort complaints related to drafts and temperature variation.