Rheem 96P series Installation Instructions Manual page 85

TABLE 14
SUPPLEMENTAL ORIFICE SIZE CHART
Notes:
1. All 92%, 95% single stage and 96% two stage units are factory equipped with orifices sized for 1100 sea level heating value gas.
2. Installer must be aware of the local heating value (sea level standard) to use the chart below.
3. This chart is based on the National Fuel Gas Code (NFGC) Annex E, 2015 Edition, based on natural gas with a specific gravity of 0.60
4. The recommended orifices below allow the furnace to operate within 10% of design rate. However, NFGC calculations are the best method.
5. Furnace operation is optimized when operating at design rate. Installer is responsible to verify rate.
6. This table applies to 90+ models only with 14,000BTU/Burner. DO NOT USE THIS CHART FOR ANY 80+ FURNACE MODEL.
*Table is derived from Annex E, 2015 Edition of the National Fuel Gas Code. To determine the correct orifice for your installation consult the National
Fuel Gas Code tables E1.1(a) and E1.1(d), 2015 Edition
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