These are especially sensitive to particulates and commonly are only specified for clean-air applications such as air conditioning. Forward-curved fans are typically used in applications where the static pressure is too high for a vane axial fan or the smaller size of a centrifugal fan is required, but the noise characteristics of a backwards curved fan are disruptive for the space.
These systems are highly responsive to particulates and are primarily used in clean-air applications such as air conditioning. Forward-curved fans are typically utilized where static pressure exceeds that of vane axial fans or when centrifugal fans would be too large, but the noise from backward-curved fans is problematic for the space.