The effect of draughts on the steady temperature distribution in a naturally ventilated enclosure

The effect of draughts on the steady thermal stratification established by a localised heat sourceat floor level in a naturally ventilated enclosure with upper and lower openings is considered. Ourexperimental observations in water using models indicate that four different steady flow patterns arepossible depending on the relative areas of the upper and lower openings. All exhibit a basic two-layer thermal stratification - a warm upper layer and a cooler lower layer, however, for a fixed total opening area the temperature distribution depends sensitively on how this area is distributed between the upper and lower openings. Implications to the comfort of occupants are discussed.