2000 Trane 80 percent furnace converted to propane. Nothing stops a Trane, and this one has proven it over last 24 years so far and Im sure there more heat for years. Best Part is a guy could wire on a plug, tape a filter on the side, rig a vent outside and get a special hose connection for a propane tank and have a completely portable furnace with help of a generator or power source. I know if a guy plans on working outside in these here parts it gets mighty cold in a few months and having a portable heat source that weighs less than a real train would be a godsend.