Image Wrong – Two combustion appliances are sharing a flue which could lead to backdrafting if one appliance is updated to a direct vent appliance and disconnected from shared chimney.
Pre-Retrofit Assessment of Combustion Appliances Description Information guide describing things to consider before attempting retrofits including any combustion appliances, or that may affect them.
Kitchen Exhaust Retrofit Duct Guide Description Guide describing the retrofit of kitchen exhaust systems, including duct sizing and routing considerations.