Raypak Hi Delta 302A-902A Installation And Operating Instructions Manual

3987%-Efficiency Boilers –Special InstructionsWater PipingAn 87%-efficiency boiler requires a minimum inletwater temperature of 120ºF (49ºC) to prevent exces-sive condensation in the combustion chamber. An87%-efficiency boiler operated with an inlet tempera-ture of less than 120ºF (49ºC) must have a manualbypass or an approved low-temperature operationsystem to prevent problems with condensation. A man-ual bypass, shown in Fig. 15, must be piped into thesystem at the time of installation. This piping is like aprimary/secondary boiler installation with a bypass inthe secondary boiler piping. Raypak strongly recomm-NOTE: The constructions of the 84%- (standard)and 87%-efficiency (optional) boilers are very similar,and they are installed to the same requirements,except as noted in this section.ends that a thermometer be placed into the boiler inletpiping next to the in/out header to facilitate tempera-ture adjustment. Inlet water temperatures below 120ºF(49ºC) can excessively cool the products of combus-tion, resulting in condensation on the heat exchanger.VentingAppliance CategoriesSee Table Q for appliance category requirements forthe 87%-efficiency Hi Delta.CAUTION: Proper installation of flue venting is criti-cal for the safe and efficient operation of the boiler.NOTE: For additional information on appliance cat-egorization, see appropriate code NFGC (U.S.) andB149.1 (Canada), or applicable local building codes.10°F T 20°F T 30°F T Min. Flow Max FlowModelNo. gpm P (ft) gpm P (ft) gpm P (ft) gpm P (ft) T gpm P (ft) T302AE 52 3.3 26 <1.0 N/A N/A 20 <1.0 26 90 9.8 6402AE 69 6.0 35 1.5 23 <1.0 20 <1.0 35 90 10.0 8502AE 87 9.7 44 2.5 29 1.1 22 <1.0 40 90 10.4 10652AE N/A N/A 57 4.4 38 2.0 28 1.1 40 90 10.8 13752AE N/A N/A 65 6.1 44 2.8 33 1.6 40 90 11.3 15902AE N/A N/A 78 8.9 52 4.1 39 2.3 40 90 11.7 17CombustionAir SupplyExhaustConfigurationHeater VentingCategoryCertifiedMaterialsCombustion AirInlet MaterialVertical Natural DraftVenting II Stainless Steel(Gas Tight)From Inside Building(Non-Direct Venting) Horizontal Through-the-Wall Venting IV AL29-4CVertical Natural DraftVenting II Stainless Steel(Gas Tight)Galvanized SteelPVCFrom Outside Building(Direct Venting) Horizontal Through-the-Wall Venting IV AL29-4C ABSCPVCTable P: Heater Rate of Flow and Pressure DropTable Q: Category Determination for Venting Purpose and Venting ArrangementNote: Basis for minimum flow is 20 gpm or 40°F ΔT. Basis for maximum flow is 90 gpm.