►► System Effect and It's Consequence by CFD ◄◄
System effect, because the fan installation in the test setup differs from how it was installed on the site.
To avoid system effect problems, we need to consider the AMCA requirement for a given fan model how it was tested, and the performance mentioned in the catalog provided by the fan manufacturer.
For all kinds of fans such as Axial fans, Centrifugal fans, and Roof fans performance ratings do not include the effect of appurtenances in the air stream and power ratings do not include drive losses.
As per the CFD analysis, it was observed that the efficiencies of the fan dropped by 10 to 12 % when the installation was not as tested. To improve efficiency on such installation (elbow at the inlet) turning vanes should be installed in the elbows.