Table 3121: Heat Pump Water Heater Fuel Switch Calculation Assumptions Component Type Values Source EFbase, Energy Factor of baseline water Variable Default: 2 1 heater Nameplate EDC Data Gathering EFfuel, Energy Factor of installed fossil Variable >=0.575 for Natural Gas 7, EDC Data fuel water heater* and Propane Gathering >=0.495 for Oil Load, Average annual Load in kBTU Fixed Varies 5 Thot, Temperature of hot water Fixed 120 °F 2 Tcold, Temperature of cold water supply Fixed 55 °F 3 EnergyToDemandFactor Fixed 0.0001916 4 FAdjust, COP Adjustment factor Fixed 0.80 if outdoor 4 1.09 if indoor 1.30 if in kitchen HW, Average annual gallons of Use Variable Default: See Table 3119 Calculation EDC Data Gathering EDC Data Gathering ResistiveDiscountFactor Fixed 0.90 6 EFNG, base, Energy Factor of baseline Fixed 0.594 7 gas water heater * For tankless water heaters, the EF should be at least 0.82 Sources: Federal Standards are 0.97 -0.00132 x Rated Storage in Gallons. Heat pump water heaters require an EF of at least 2.0. Conservation Program: Energy “Energy Conservation Standards for Residential Water Heaters, Direct Heating Equipment, and Pool US Dept of Energy Docket Number: EE–2006–BT-STD–0129, p. 30 Heaters” Many states have plumbing codes that limit shower and bathtub water temperature to 120 °F. Mid-Atlantic TRM, footnote #24 The load shapes can be accessed online: DEER Database Engineering Estimate Federal Standards are 0.67 -0.0019 x Rated Storage in Gallons. For a 50-gallon tank this is 0.575 for natural gas/propane and 0.495 for oil. For a 40-gallon tank this is 0.594 for natural gas. Conservation Program: Energy Conservation Standards for “Energy
Table 3121: Heat Pump Water Heater Fuel Switch Calculation Assumptions Component Type Values Source EFbase, Energy Factor of baseline water heater Variable Default: 2 1 Nameplate EDC Data Gathering EFfuel, Energy Factor of installed fossil fuel water heater* Variable >=0.575 for Natural Gas and Propane >=0.495 for Oil 7, EDC Data Gathering Load, Average annual Load in kBTU Fixed Varies 5 Thot, Temperature of hot water Fixed 120 °F 2 Tcold, Temperature of cold water supply Fixed 55 °F 3 EnergyToDemandFactor Fixed 0.0001916 4 FAdjust, COP Adjustment factor Fixed 0.80 if outdoor 1.09 if indoor 1.30 if in kitchen 4 HW, Average annual gallons of Use Variable Default: See Table 3119 Calculation EDC Data Gathering EDC Data Gathering ResistiveDiscountFactor Fixed 0.90 6 EFNG, base, Energy Factor of baseline gas water heater Fixed 0.594 7 * For tankless water heaters, the EF should be at least 0.82 Sources: Federal Standards are 0.97 -0.00132 x Rated Storage in Gallons. Heat pump water heaters require an EF of at least 2.0. “Energy Conservation Program: Energy Conservation Standards for Residential Water Heaters, Direct Heating Equipment, and Pool Heaters” US Dept of Energy Docket Number: EE–2006–BT-STD–0129, p. 30 Many states have plumbing codes that limit shower and bathtub water temperature to 120 °F. Mid-Atlantic TRM, footnote #24 The load shapes can be accessed online: DEER Database Engineering Estimate Federal Standards are 0.67 -0.0019 x Rated Storage in Gallons. For a 50-gallon tank this is 0.575 for natural gas/propane and 0.495 for oil. For a 40-gallon tank this is 0.594 for natural gas. “Energy Conservation Program: Energy Conservation Standards for
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