Once I figure out how to get the sheet metal covers off the indoor
evaporator coil, what kind of cleaning liquid or spray is the strongest and
still safe to use on the coils? I'm thinking of something I can get at the
local hardware store, not something I'd have to go to an AC specialty shop
to find... this evaporator has not been cleaned for 20 years, mainly
because the panels are so hard to remove. Still seems to work good though,
but I'm sure it will be more efficient once I get the dust out.