EFFECT OF RIDGE OPENING WIDTH ON NATURAL VENTILATION PERFORMANCE DURING SUMMER

Inside temperatures and estimated ventilation rates based on CO2 measu rements were compared in a naturally ventilated barn under summer cond itions using ridge opening widths of 0, 25, and 125 mm. Only minimal i nside to outside temperature differences were measured for any ridge o pening width during the day. There were higher frequencies of high ven tilation rates with either the 25 or 125 mm wide ridge opening as comp ared to the closed ridge; however, the estimated ventilation rates wer e greater than one air change per minute 80, 87, and 92% of the time f or the 0, 25, and 125 mm ridge opening widths, respectively. The size of sidewall and ridge openings required for summer ventilation could t herefore be based on wind effects alone since thermal buoyancy effects are considered to be negligible.