We bought probably the same vent hood from Lowes over memorial day weekend. Our old (30 years) Ventahood vent pipe was on a 14 inch center while the new Braun was on a 16 inch center. I was not going to cut a smily face in the bottom of the cabinet so back to Lowes for the carbon filter. Yes the old vent pipe is still in place covering the hole. We just plan on changing the filter.