Fine particle air filter for wood workshop (Painswick GL6)

Rutlands.co.uk brand:0
"Specifically designed to remove fine dust out of the [wood] workshop's atmosphere, filtering 98% of airborne dust particles down to 5 micron and 86% down to 1 micron. There is no better way to silently clean and filter your workshop environment."
Brand new, complete & in full working order but emits a high-pitched whine when running (possibly not when in medium speed setting). May not be a problem in a noisy workshop or just run it on the timer when workshop empty of people. Needs mains supply, last photo similar item ceiling mounted in workshop.
£200 on Rutlands website.