Sunny Gulf of Florida here
One window unit, shady but exposed to rain does clog up the drain with some
kind of algae/fungus, clogs drain every two or less yrs .. makes odd fibrous
jello like globs - local neighborhood hardware has pills to prevent it so it
must be popular globs - one or more of these $0.15 pills needs to be
dropped in monthly or so to keep the drain open. I pretty much annually
take a hose to the outside and flush every which way trying to keep the salt
air corrosion to a minimum. When the drains clog I shove it in a bit and
take unroll the hose through the house and flush from the inside after
taking some sheet metal loose and man can you see jello then everywhere -
hard to get it out.

"jt" wrote in message
oups.com...
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...