FANUC Controller Coooling - Dirty Environment

Has anyone done anything clever to fix the cooling for a R30iB controller in an extremely dirty environment? Filter get clogged too quickly so the controllers overheat. I do have chilled water available. In hindsight, we should have put in a control room but we don't have that kind of room now. Couldn't find a water to air heat exchanger to replace the factory air to air heat exchanger.