what size furnace is this, btu ? double wall bvent (chimny) you run up thru ceiling and out roof . keep a min of 1 " clearance from all combustable material, wood,sheetrock ect,, buy registers, one on each side and one in the front ,place high so its not gonna blow in your face, dont go to small with the registers or the units high limet will cut out. propane preasure feeding the furnace should be at a set preasure. and is allways adjusted and checked at furnace first start up. because the furnace is moved to a new location with a differant propane set up.i would check the system.