What are furnace filters called in the uk?

[Deadeye]

As title really... I want to recirculate my dust extraction air within my garage and to do so it'd be good to put it tinto a cubic box with 4 sides using filters.

 

[Steve Maskery]

We would call a furnace a boiler. But is this the sort of thing you are looking for?
https://www.zoro.co.uk/shop/fluid-power ... CAQAvD_BwE

 

[sunnybob]

youll find what youre looking for in here
http://www.jasunfiltration.com/