What is a "Top-Vent" furnace?

A "Top-Vent" furnace must be vented vertically up through the roof. This way it may be centrally located inside the home on an inside wall. The combusibles will go up the vent and discharge outside. Monterey Top-Vent Gravity Models include #2509621, #2509622, #3509621, #3509622, #5009621 and #5009622. Forsaire Top-Vent Counterflow Models include #6008532, #6008531, #3508732, #3508731, #5008732, #5008731, #6508732, #6508731, #3508332, #3508331, #5508332 and #5508331. Console Hearth Heater Models include #2001622, #2001621, #3501522, #3501521, #3501922, #3501921, #5001522, #5001521, #5001922, #5001921, #6501522, #6501521, #6501922, #6501921, #2001622, #2001621, #3502522, #3502521, #3502922, #3502921, #5002522, #5002521, #5002922, #5002921, #6502522, #6502521, #6502922 and #6502921. Floor Furnace Models include #4505622, #4505621, #6005622 and #6005621.