We have an FFU that was installed in a ceiling with its back exposed to an attic, where it was used for a couple years and then not used for 7 years. Is it salvageable?
I was thinking about changing the HEPA filter on it (in addition to changing the pre-filter of course), but it doesn't seem like the FFU is made to be taken not made to be taken apart easily.
What is y'alls' protocol for FFU maintenance and for changing or not the filters?
Do you ever perform a test of the HEPA for leaks?
As always, thanks a ton for the help!