While looking at a home to potentially purchase, I noticed that the home has no supply registers or return vents. The house is a mid-1940s ranch. The home has a newer (2002) forced air gas furnace. I found a guy who had done some work at the house (not HVAC work), and he said the house has a "forced air radiant system." He said that ductwork runs above a "false ceiling" warms the void space, and radiates heat through the ceiling. He THINKS that the return air comes from the end of the void space, back down an interior wall to the return side of the heating unit. Anybody out there know ANYTHING about this type of heating? Thanks.