Well that isn't an issue with the psu itself rather the environment the comp was in that caused to not have proper air flow and acquire huge amounts of dust that caused heat to build up.

In any case the issues you had could occur with any electronics.

There are cases that have dust screens on them including the psu. PSU dust screens at least in my case you can pull them out, clean them off, put them back in.

Keeps the dust from clogging the fan and psu innards.

The dust screens on the intake fans man they have a layer of dust every few days I have to wipe off. No dust yet in the case.