On 2 Jun 2004 22:34:05 -0700, (Paul James) wrote:

My main concern would have to be running all that water laden air over
your heat exchanger in the furnace. A furnace is not designed to
handle that level of moisture. If you have a lot of condensation on
the heat exchanger you could shorten the life of your furnace.

Uhoh, that's another factor that did not occur to me, thanks. I'd have
to put some sort of anti-backflow flap between heater/AC and the
ductwork junction.