6,000,000 BTU high efficiency hot water plant 3,500 gallon hot water heat recovery and storage with supplemental 50 GPM on demand hot water system. 12 on demand water heaters totaling 2,400, 000 BTU/HR heat 50 GPM of water from 55° F to 140° F at 95% efficiency Hot water system stores 3500 gallons of 180° F water produced at over 92% efficiency. Mixing valves, VSD pumps and bladder tank are used to deliver water to 3 different locations at 3 different temperatures with a constant pressure of 60 PSI. Total flow varies from 10 to 300 GPM. 100 HP, 15 PSI, High-Efficiency Cast Iron Steam Boiler for Process and Heating Triplex 1,000,000 BTU BoilersThe system heats a water source heat pump loop serving an industrial mill complex. High and low pressure duplex VFD hot water pumping system with 3,000 gallon storage tank. Two 150 HP high-pressure high-efficiency on-demand steam boilers with built-in economizers. 500 GPM direct injection steam to hot water generators.