Do window a/c units have to be hosed out regularly? I see corrosion of
the case after less than a year, and the fins seem to clog up with
algae or something near the wetted bottom. This is in a very hot,
salty air environment sheltered from the rain.

I saw some older units nearby, also panasonic, with just shocking
corrosion - the fins almost eaten totally away to bare coils (lower
ones) and some casing corrosion where the vents were stamped into the
sides (stamped after painting, so bare metal is exposed).

Unfortunately it is awkward to hose the thing - maybe a spritz sprayer
is possible. I didn't expect this corrosion and worry about algae or
whatever messing up efficiency, but no preventative maintence is
mentioned in the user guide. Maybe the exposed metal vents in casing
should be painted, but probably too late. Thanks for any advice...