Most of the ranges I look at in the professional area...Wolf, Thermador, Miele etc. mention that 30" is the minimum height from cook top to hood...the space I have currently is about 27 1/2" and I cannot change the height without major construction. This is for a 30" range and hood (300 CFM)...do you foresee issues with this? Thank you!
I'd be more concerned about maximum distance to get enough effective airflow. For minimum I'd recommend tallest pot plus 6"-8" so that you can take the lid off and stir without the hood getting in the way.