Good Morning 

We have a project to start internally in a large empty food factory room. This will require the use of excavation plant. Can any practitioners with experience of this type of project give me some guidance on how to best go about this and how to implement the use of diesel particulate filters ?

I have been informed that the plant involved does not have DPFs

Would large extraction fans suffice ?

DPF's have nothing to do with using plant indoors.

Your issue with ICE equipment is the combustion exhaust which to prevent significant build up in the work area is ideally tackled using extraction hosing and fans to an external exit point (and not the door used for access/egress where it can be blown back inside).

A "big fan" in the area will merely circulate whatever is present - your task, like an MOT garage measuring emissions, requires extraction.

When we have had to work within buildings using excavators we have used HD90 or M60 filters try looking for ravex or simular.