Want to replace an old fan without fixing the old ceiling opening. The current opening is 14 1/2 x 8 1/2. The fan fits between the ceiling joists. I found a new fan with the exact right dimensions, but unfortunately the duct opening is along the 8 1/2 dimension, which means it faces the joist - impossible. Looking for a fan of that size where the duct comes out along the long dimension, so the unit will fit in the old hole. Know of any? Thanks.