Bryan Indirect Water Heaters are available in sizes to 8,000,000 Btu/hr with water heating capacities to 7,680 gal/hr at 100-degree temperature rise (40-degrees to 140 degrees F). The water heaters utilize an indirect heat exchanger method, meaning the primary water in the heater is maintained at a constant temperature and recirculated only within the heating vessel. The heat exchanger, placed in the primary water, absorbs heat and transfers it to the water flowing through its copper tubes. These water heaters require very little floor space and are suited for multi-purpose heating. www.bryanboilers.comBryan Steam LLC.