With a forward-curved fan wheel (forward-curved blades) a given air duty is achieved with the smallest possible constructional volume. The fan wheel produces almost exclusively kinetic energy, this being converted into static pressure in the fan housing. The forward-curved impeller produces a given pressure at about half the circum-ferential speed of a backward-curved wheel and is therefore much quieter. The higher number of blades results in a wider noise spectrum / frequency band. Within the normal application range, the total pressure characteristic curve for the forward-curved impeller type is flat. At constant rotational speed, the power requirement for forward-curved wheels rises progressively with the volume flow rate.
Conclusion: For the same application, the forward-curved fan wheel is 10 to 25% smaller than a backward-curved wheel, has a lower noise level due to a lower speed, but requires slightly more power input.
You can find our forward-curved fan impellers here:
Comparison of fan wheel types Centrifugal impeller, Mixed Flow impeller, Axial impeller, Backward-curved impeller, Radial impeller, Forward-curved impeller:
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