Using the Fan Assessment Numeration System (FANS) in Situ: A Procedure for Minimizing Errors During Fan Tests

The Fan Assessment Numeration System (FANS), developed by the USDA-ARS Southern Poultry Research Laboratory and refined at the University of Kentucky, has become a useful tool to measure airflow of agricultural ventilation fans in situ. However, procedures for using FANS for in situ ventilation fan performance have not been standardized. A common practice for changing the static pressure inside tunnel-ventilated animal housing during fan tests is to energize other fans, although little is known about the effects of adjacent operating fans on FANS test results. Therefore, this study evaluated the effect of the position of various operating fans relative to the FANS unit and test fan. Tests were conducted for ten 1.22 m diameter fans of two different models in two types of poultry barns in which fans were installed either immediately next to each other or 1.6 m apart. The effect of the FANS unit placement at both the intake and discharge sides of the tested fans was also evaluated. Airflow values obtained for different FANS unit placement and operating fan combinations at constant static pressure differed by as much as 12.6% ±4.4% compared to the control configuration with the FANS placed on the intake side of the sidewall fans. In contrast, placing the FANS unit on the fan discharge provided valid fan test results compared with the (inside) control configuration. A standardized procedure for using the FANS unit to test fans in situ was developed and is suggested for future FANS use.