I wish to install an over the range microwave (probably a GE Adavantium 240 V model) and vent the hood to the outside. Researching this, I see that it has a 300 CFM fan as do most of the over the range microwaves. Is this sufficient to vent to the outside side and what size duct should I use? As it will be mounted on an interior wall, my run will be about 15' with one 90. Also, is the placement of the vent outlet the same across all manufacturers? I haven't bought the unit yet, and want to run the duct first.