A few things I need to understand. My old vent pipes are swathed in asbestos tape-like insulation. Does that have to be removed or can a new furnace be hooked up to the same pipe (they are about 10" or so in diameter) and, also, does all old ductwork have to be replaced? Cold air returns - my upstairs has none - house is only 1260 sq ft. and I probably will put in the Infinity (variable) or Performance (not variable) with Performance AC. Is it absolutely necessary to have cold air returns installed upstairs?
Thanks for the help. This is a terrific forum. Thanks, Darby