A 7″ vent connector is to be connected to a vertical vent along with 5″ and 4″ vent connectors. All three appliances have draft hoods. Type B vent materials are used. They are catagory I appliances on the same floor. What is the minimum size required for the common vent when you will be using the alternate method of sizing in the Code?

A 7″ vent connector is to be connected to a vertical vent along with 5″ and 4″ vent connectors. All three appliances have draft hoods. Type B vent materials are used. They are catagory I appliances on the same floor. What is the minimum size required for the common vent when you will be using the alternate method of sizing in the Code?