Summer Ventilation 101Summer Ventilation 101The primary goal of summer ventilation is to remove the heat produced by the birds in the barn. In a well designed and managed barn, you should be able to remove almost all of the bird heat and keep the average barn temperature from rising no more than 1 C. The number of fans needed to achieve this goal should be considered the minimum in any barn design. Adding more fans will not remove a lot more heat from the barn but may increase airspeed over the birds and provide a beneficial wind chill.
If you want to keep the temperature inside your barn the same as outside, what summer time fan capacity is recommended? In the past, fan capacity of 2.0 to 2.5 cfm/kg of turkey and 2.5 to 3.5 cfm/kg of chicken has been recommended. Some of these recommendations do not reflect the differences in heat production between the birds that were grown 30 years ago and those that are grown today.
Based on a survey of over 40 poultry farms in Manitoba, a minimum summer time fan capacity of 3.0 cfm/kg is recommended for most birds. That translates to 5 cfm for a 1.7 kg laying hen and 6 cfm for a 2 kg broiler. The reason for the 3 cfm/kg recommendation is demonstrated in the data from the survey is displayed in the chart, "Relationship between heat build up in barn and airflow relative to body weight."
