On-Farm Ventilation Fan Performance Evaluations and Implications

Falls are key components of mechanically ventilated poultry housing. When installed, the fan is often fitted with I or more accessories, including safety guards, shutters, and discharge cones. These first 2 accessories usually reduce the airflow and fail efficiency, whereas discharge cones improve airflow. Field performance of a fail is further impacted by accumulated dirt Oil the blades and shutters, mechanical wear, and degree of maintenance. Performance of all ventilation fans oil 2 commercial broiler farms was determined during an air emission monitoring project. Each fail was tested using the Fail Assessment Numeration System at a range of static pressures typical of its regular operating range. The performance of otherwise identical falls was shown to vary by Lip to 24%. This variation in performance is attributed to accumulated dirt and corrosion, difference,, in the resistance to flow imposed by the shutters, and differences ill motor and bearing wear due to Rill time and aging. A small reduction in fall speed from slipping or worn belts had a lame effect oil airflow generated by the 1,220 mm (48 in.) diameter fans. The power consumption of each fall Was also measured as part of the evaluation process and revealed considerable variation among these falls.