SUGGESTED KC1000 WATER HEATER SPECIFICATION GENERAL The contractor shall furnish and install a modular domestic water heating plant as shown on the plans, in accordance with AERCO INTERNATIONAL, INC. operating and maintenance manuals, and all applicable codes and authorities having local, state and federal jurisdiction. The domestic water heating plant shall consist of (2) Model KC1000-GWWLN semi-instantaneous water heaters as manufactured by AERCO INTERNATIONAL, INC., no exceptions unless approved prior to bid by Engineer. Mechanical Contractor shall be solely responsible for all cost associated with system design changes including redesign, additional components and engineering drawings due to Alternate Manufacturers. Manufacturer shall have a minimum of fifteen (15) years of experience in the design, manufacture and operation of condensing, modulating water heater systems. PERFORMANCE Each water heater shall have a full load input of 970 MBH with a gross output of 902 MBH (depending on return water temperature) when fired with natural gas or propane. Each unit shall operate with a minimum ANSI Z-21 of 93% efficiency. Efficiency changes shall relate inversely to water heater firing rate and the water heater manufacturer shall certify this performance characteristic with testing done under conditions representative of an actual installation. CONSTRUCTION The water heater shall be of a sealed combustion, fire tube, forced draft, condensing design, capable of metering fuel and air to maintain optimum combustion efficiency. The combustion chamber and tube design shall operate throughout the full range of feed water temperatures without degradation to the heat exchanger/combustion chamber. The heat exchanger and combustion chamber shall be manufactured of 90/10 copper-nickel; copper fin-tube or coated combustion chamber and heat exchangers are not acceptable. Internal temperature control accessories such as primary circulator pumps or internal temperature by- pass valves required to protect the combustion chamber and heat exchangers are not acceptable. The heat exchanger shall be ASME stamped for a working pressure not less than 155 psig. Each individual water heater shall be capable of an 11:1 turndown of firing rate without any loss of combustion efficiency. Gas and air valves shall share a common shaft. External linkages, individually modulating gas and air valves, staged combustion and/or multiple ON/OFF burners shall not be acceptable design substitutes. The water heater shall include a combustion system capable of operation on both natural gas and propane. Natural gas shall be the primary fuel and propane the back-up fuel. Each water heater shall be capable of operating continuously on the back-up fuel for a period of no less than 14 days. The performance of the backup-up fuel shall not deviate from that of the water heater operating on its primary fuel; specifically in the area of efficiency, turn-down and emissions. CONTROL Each boiler shall be capable of controlling its heat output to within +/- 4° F without the need for storage tanks, mixing valves or other temperature averaging components. WARRANTY The pressure vessel of the water heater shall carry a 10 year warranty against failure due to corrosion or defects in materials or workmanship. The heat exchanger tubes/combustion chamber assembly shall be warranted against failure due to thermal stress failure or condensate corrosion for a prorated 5 year period. The control panel on each boiler shall be conditionally warranted against failure for (2) two years from shipment. All other components with the exception of the igniter and flame detector are conditionally guaranteed against any failure for 18 months from shipment.