Heat transfer to calculate minimum ventilation rates for broilers house.

The correct use of minimum ventilation and heating system on broiler’s brooding phase is important even in tropical climates such as Brazil. Thus, the study of heat exchange is important to determine new materials of insulation for the walls and roof, in order to achieve optimal levels of thermal comfort to raise the birds. The objective of this study was to evaluate the actual minimum ventilation rate compared to the ideal ventilation rate calculated throw the heat balance of the brooding area from a tunnel ventilated broiler house totally closed with black side curtains and to improve the minimum ventilation and the heating systems to reach the ideal temperature inside the brooding area. The trail was performed at Mombuca city, State of Sao Paulo. The broiler house had a brooding area that was divided in 80 grids to collect the climatic variables (dry bulb temperature, relative humidity and air velocity) at the birds’ level and inside and outside the broiler house and the CO2 concentration was collected only inside the brooding area. The inside and outside surface temperature of all the brooding area (curtains, ceiling and roof) was collected using a thermograph camera. All data were collected 4 times a day (9AM, 2PM, 5PM and 9PM), in winter-time. The minimum ventilation rate was calculated according the methodology proposed by Albright (1990). The temperature was always below the ideal temperature according Nicholson et al. 2004 demonstrating the need of a 58Kg of diesel/day to reach the birds ideal temperature.