The following pictures indicate how to choose the appropriate size for your custom range hood:
-Range Hood Height : Ceiling Height - A - B(Stove Height)
-A (distance from cooktop to bottom of range hood): 30"-36"
-Range Hood Width : as Wide as cooktop or 3"-6" Wider
-Range Hood Depth : 21"-24"
-Range Hood Height : Ceiling Height - A - B(Stove Height)
-A (distance from cooktop to bottom of range hood): 30"-36"
-Range Hood Width : 3"-6" Wider than cooktop
-Range Hood Depth : 27"