Powered Vent

Just inspected a house with a fifty gallon Bradford White Defender water heater with a powered vent system. Does anyone out there have information regarding the benefit of powered ventilation of water heaters?

The powered ventilator allows the plumber to run the flue to the nearest exterior wall rather than running up through a chase that goes through several floors. You’ll especially see them on newer builds where the furnace is high efficiency and does not have a flue that runs through the roof.
Because of the powered vent, the flue can be PVC, due to the cooled gases.

Would this indicate that the water heater is of higher efficiency than a conventionally vented water heater, or is room air drawn to cool the exhaust?