I have a high efficiency Amana vented horizontally just above the sill
plate. It's 12 degree's f here in Michigan now. There is less condensation
coming out than when you start a cold car to give a comparison. i have a
bedroom window about 4 feet away that has never had condensation on it. The
bushes 1 foot away look no different than those 15 feet away. This will be
our 3rd winter on this furnace. I'm happy with it.