I've been saddled with the duty of advising/helping a family member with replacing their warm air heating system. They want to add air conditioning to the new furnace. It is a natural gas furnace......one zone Furnace is located in a full basement. Anyone know of any reputably installer on Long Island? Furnace makers.....Lennox, Rheem,Luxaire,York, Byrant, etc? Any thoughts? Do they make furnaces that go into chimneys anymore or are they all vented out the side wall with PVC?