Can fan-assisted units, such as the Pennant and JVi units, be vented with natural draft units (in the same vent)?
The National Fuel Gas Code allows for fan-assisted and natural draft units to be vented together, vertically, if they are certified as category 1 appliances, and the vent system is designed properly. As always, check your local codes. Care must be exercised in the systems to prevent the flue gases of one unit to push through another unit, in the event of a blocked vent. Safety devices must be interlocked with each unit to prevent the units from operating when ANY of the portions of the vent or vent connectors are blocked.
