The machine looks exactly like this one. Scroll down there’s a picture of the fan, which is 400mm diameter, 875 m³/hr, 500W tangential thing.
https://www.ebay.co.uk/itm/60W-CO2-LASER-ENGRAVING-CUTTING-MACHINE-CARVING-TOOL-CUTTER-WOODWORKING-CRAFTS/332767386163?epid=17009131286&hash=item4d7a7b5a33:g:q0sAAOSw-zNbdjBb.
Noise level at the exhaust is over 90dBA. However differently we mount it. it’s still a darned noisy fan.
We have an air flow meter coming to see what it’s actually achieving in the 150mm duct. It should be 49 km/hr, and 198 km/hr at the 75mm outlet. We’ll see.
We think a mixed-mode ducted fan should be OK, but we aren’t experts.
Anyone?
Thanks