the ETDF is applied. The demand reduction is taken as the annual energy savings multiplied by the ratio of the average demand between 2 PM and 6 PM on summer weekdays to the total annual energy usage. kWpeak = ETDF ETDF (Energy to Demand Factor) is defined below: The ratio of the average demand between 2 PM and 6 PM on summer weekdays to the total annual energy usage is taken from an electric water heater metering study performed by BG&E (pg 95 of Source 6). The parameters in the above equation are listed in Table 245. Table : Heat Pump Water Heater Calculation Assumptions Component Unit Values Source , Energy Factor of baseline water heater None See 1, 7 Table 248 Default= 0.945 (EF for 50 gallon) , Energy Factor of proposed efficient water gallons EDC Data Gathering heater Default : 2.0 ≤55 Gallons: >55 Gallons: 2.2 , Hot water used per day in gallons 50 2 HW , Temperature of hot water °F 119 3 , Temperature of cold water supply °F 55 4 , COP De-rating factor Fraction 5, and discussion below Table 249 , Equivalent Full Load Hours for cooling Table 246 6 , Equivalent Full Load Hours for heating Table 247 6 HSPF , Heating Seasonal Performance EDC Data Gathering 7 Factor Default= 7.4 SEER , Seasonal Energy Efficiency Ratio EDC Data Gathering 7 Default= 12 ETDF , Energy to Demand Factor (defined 0.00008047 8 above)
the ETDF is applied. The demand reduction is taken as the annual energy savings multiplied by the ratio of the average demand between 2 PM and 6 PM on summer weekdays to the total annual energy usage. kWpeak = ETDF ETDF (Energy to Demand Factor) is defined below: The ratio of the average demand between 2 PM and 6 PM on summer weekdays to the total annual energy usage is taken from an electric water heater metering study performed by BG&E (pg 95 of Source 6). The parameters in the above equation are listed in Table 245. Table : Heat Pump Water Heater Calculation Assumptions Component Unit Values Source , Energy Factor of baseline water heater None See Table 248 Default= 0.945 (EF for 50 gallon) 1, 7 , Energy Factor of proposed efficient water heater gallons EDC Data Gathering Default : ≤55 Gallons: 2.0 >55 Gallons: 2.2 HW , Hot water used per day in gallons 50 2 , Temperature of hot water °F 119 3 , Temperature of cold water supply °F 55 4 , COP De-rating factor Fraction Table 249 5, and discussion below , Equivalent Full Load Hours for cooling Table 246 6 , Equivalent Full Load Hours for heating Table 247 6 HSPF , Heating Seasonal Performance Factor EDC Data Gathering Default= 7.4 7 SEER , Seasonal Energy Efficiency Ratio EDC Data Gathering Default= 12 7 ETDF , Energy to Demand Factor (defined above) 0.00008047 8
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