RBI Futera XLF Installation And Operation Instructions Manual

Also see for FUTERA XLF Series: Manual Control manual Manual Installation and operation instructions

RBI Futera XLF Installation And Operation Instructions Manual Manual pdf 22 page image

Finned copper tube gas boilers & water heaters – Boiler Manual22Table 8 Futera XLF Heat Exchanger SelectionTable 9 Futera XLF Pumping Performance RequirementsMaximum (Hard - 18+ Grains)CalculatedGPM PD (FT) PD (kPa) ∆T (°F)2500 315 18.86 55.6 143000 315 19.75 58.2 173500 315 20.65 60.8 194000 315 21.54 63.5 225000 315 23.34 68.9 28Recommended (Normal - 8-18 Grains)CalculatedGPM PD (FT) PD (kPa) ∆T (°F)2500 210 9.34 27.5 213000 210 9.76 28.8 253500 210 10.18 30.0 294000 210 10.61 31.3 335000 248 19.70 58.0 35guidelines in the Heat Exchanger SelectionTable (Table 8) and the PumpingPerformance Table (Table 9). Scale freeoperation can be achieved by using waterwith a hardness between 8 and 18 and bymaintaining the pH between 5 and 9. Followthe conditions listed under NORMAL inthe table. In some areas of the countryadditional precautions must be observeddue to unusual characteristics of the localwater supply. Call the nearest RBIrepresentative for details.To properly size the pump a grain hardnessand pH test must be taken at the installationsite before the order is placed. Proper pumpsizing will improve heater performance andhelp ensure heater longevity.Expansion TankAn expansion tank or other means to controlthermal expansion must be installed in thewater heating system if back flow preventiondevices are installed.Pump RequirementsThis low-mass water heater requires acontinuous minimum water flow forproper operation. The low water flowswitch provided for this unit will shutdown the water heater if flow falls below therequired minimum level. Table 9 providesthe heat exchanger pressure drop chart andtemperature rise table. The temperature riseacross the water heater must never exceed35oF, 19.4oC.Cold Water SupplyThe cold water supply must be piped tothe water heater’s outlet piping betweenthe water heater and the hot water storagetank. This will prevent untempered waterfrom entering the water heater. See theTemperature Rise Control section.Two typical water heating systems areshown in Figures 14 and 15.