Hi!
I have six window air conditioner units in my house and central heat
for heating. The insulated ducting for the heat, installed in 1975, is
fiberglass with a foil exterior lining. Do I need to use another type
of ducting due to mold potential?

Also where do I find an energy calculator for window units vs. central
air? I want to have only one window unit- and in a room not used that
often.
Thanks
KAT
Macon, GA where it's hot as heck