Improving Sound Quality

Model QEP

The QEP plenum fan is designed to improve sound performance. Greenheck designers used computational fluid dynamics to optimize the aerodynamic shape of the airfoil blades, wheel cone, and inlet venturi to improve the product's efficiency. Higher efficiencies result in lower sound power levels across the eight octave bands for a quieter operating fan. In addition, the 12-bladed QEP design improves sound quality by reducing low frequency tones that are difficult to attenuate and annoying to listeners.

The chart at the right shows a typical by octave sound power comparison for a 9-blade centrifugal wheel and 12-blade QEP wheel. Notice that overall, the outlet sound levels for the 12-blade QEP are less than the 9-blade design. In addition, the 12-bladed QEP design has dramatically lower sound power in the 63 and 125 Hz octave bands.

Hear the sound comparison for yourself

Greenheck has thoroughly tested the sound characteristics of the QEP. The following simulation includes actual audio from these tests comparing a 12-bladed QEP wheel to a traditional 9-bladed centrifugal wheel.