Why would an auxiliary hood be installed for a PMG-60 Powermite® Gas Booster Water Heater?

Hatco offers an auxiliary hood that can be placed directly over the PMG-60 that will direct flue gas products to the rear of the Booster Water Heater. The flue gas may be directed to exhaust behind the counter or dishwasher or up into a nearby ventilation/exhaust hood. (See manual for details.)