FIELD EVALUATION OF TEMPERATURE AND VELOCITY UNIFORMITY IN TUNNEL AND CONVENTIONAL VENTILATION BROILER HOUSES

Abstract

This field evaluation compared the temperature and velocity uniformity within two commercial broiler houses.One house used conventional sidewall ventilation and the other used tunnel ventilation strategies. One goal of hotweatherventilation is to exchange enough air to remove bird body heat. Introducing a significant convective (wind chill) over the birdsis the primary objective of tunnel ventilation. The tunnelventilated house had average air velocities of 1.7 m/s [335 feet perminute (fpm)] and 2.6 m/s (509 fpm) during the first and second study period, respectively. Wind played an important rolein determining air speed and direction within the curtain inlet end of the tunnelventilated house. Tunnel air speed at birdlevel was about twothirds the air speed at human level. As anticipated, little wind chill was present in the conventionallyventilated house. The average air speed was 0.4 and 0.5 m/s (83and 100 fpm) during the two 1h, study periods. Aboutonehalf the crosssectional area exhibited still air [<0.25 m/s (50 fpm)] conditions. Within the tunnelventilated house, birdlevel was the warmest zone in the exhaust fan end of the house despite the high air speeds and substantial air exchange rates.On average, the conventional house temperature was approximately 3.8.C (6.9.F) warmer than the outdoor temperature ascompared to 2.6.C (4.7.F) for the tunnel house. Within both houses, the maximum difference between the maximum andminimum monitored temperatures was 2.8.C (5.0.F), which indicated acceptable temperature uniformity.