Hey guys so I called alpine home air products, the salesman suggested I buy a high efficient furnace so I can just run the intake and exhaust air pipes right out the side of the garage instead of up through the ceiling. From the unit to the wall is 16'. 1/4" per foot raise would be a 4" drop from the ceiling for the unit to hang. My question is can I run 2 45° elbows straight to the ceiling and have the remaining length (12'-+) flush against the ceiling. Or do the pipes need to have a consistent raise the whole length? Thanks Evan