Click on “Download PDF” for the PDF version or on the title for the HTML version.

If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

Emission rates of gaseous pollutants from intensive livestock housing are obtained as the product of gas concentration and the ventilation rate. Much effort has been expended developing methods to measure gas and particle concentrations; however accurate in-situ air flow measurements have always been particularly problematic. A Fan Assessment Numeration System (FANS) can be used in the livestock houses to obtain an in-situ calibration of each fan in its exact configuration including shutters, louvers, and discharge cones. An evaluation of the typical mode of use of the FANS to determine the fan performance characteristic for fans between 450- and 1290-mm diameter is reported. The FANS is placed directly in front of the fan to be tested, sealed to minimize air leakage and a single measurement taken at each static pressure is reported. The determination of fan airflow with FANS is very repeatable (within 0.26% of nominal reading), indicating that replicated tests are not required. There was no 'penalty' associated with the FANS when testing fans with diameters of 915 mm or less, or 1220-mm diameter fans with capacities of less than 34,000 m3 h-1. Based on limited testing, a significant 'penalty' could exist for fans with diameters larger than 1220 mm or with higher performance characteristics. When using a FANS to determine the performance characteristic of a fan with a diameter greater than 1220 mm, the 'penalty' should be determined by evaluation in a fan test facility. For fans significantly smaller than the FANS unit, test results suggest that no transition is needed.