Duct Size	A	B
6 inch	9"	3"
8 inch	9"	3"
10 inch	12"	3"
12 inch	12"	3"
14 inch	12"	3"
16 inch	12"	3"
18 inch	12"	3"
20 inch	12"	3"
24 inch	12"	3"

 

Measure your specific application, then refer to the chart to select the appropriate wye size.