Thermal environmental conditions in four curtain-sided naturally ventilated freestall barns in Minnesota

Curtain-sided naturally ventilated freestall dairy barns are used widely in Minnesota. Temperature and relative humidity levels were measured using data loggers in four naturally ventilated freestall dairy barns with split curtains. All of the barns had either insulated roofs or insulated ceilings. Six months of data are presented in this paper. Monthly average outside temperatures were warmer than historical averages for five of the six months. Week and hour long averages were evaluated. Hourly average temperatures between interior freestalls were usually within 2.5 C of each other. Vertically, between cow level and near the ceiling, hourly average temperature differences usually varied between -1.5 and 2.5 C. Weekly average temperature differences between inside and outside ranged from 6 and 20 C when average weekly outside temperatures were below freezing. Three out of four barns had average weekly inside temperatures within 1 C of outside averages during warm weather.