Definition of Terms Table : Low Flow Showerhead Calculation Assumptions Parameter Description Type Value Source GPMBase Gallons per minute of baseline Fixed Default value = 2.5 or 1 showerhead EDC Data Gathering GPMLow Gallons per minute of low flow Variable Default value = 1.5 or 2 showerhead EDC Data Gathering Average time of shower usage per Fixed 7.8 3 person (minutes) Npersons Average number of persons per Variable Default SF=2.7 4 household Default MF=1.8 Default unknown=2.6 Or EDC Data Gathering Average number of showers per person Fixed 0.6 5 per day days/year Number of days per year Fixed 365 S/home Average number of showers in the home Variable Default SF=1.7 (89.6% 6 of homes) Default MF=1.3 (10.4% of homes) Default unknown = 1.6 Or EDC Data Gathering Tout Assumed temperature of water used by Fixed 101° F 7 showerhead Tin Assumed temperature of water entering Fixed 55° F 7,8 house UH Unit Conversion: 8.33BTU/(Gallons-°F) Fixed 8.33 Convention UE Unit Conversion: 1 kWh/3413 BTU Fixed 1/3413 Convention RE Recovery efficiency of electric water Fixed 0.98 9 heater FED Energy To Demand Factor Fixed 0.00008013 10 ISR In Service Rate Variable Variable EDC Data Gathering ELEC Percentage of homes with electric water Variable Default=43% 11 heat Or EDC Data Gathering
Definition of Terms Table : Low Flow Showerhead Calculation Assumptions Parameter Description Type Value Source GPMBase Gallons per minute of baseline showerhead Fixed Default value = 2.5 or EDC Data Gathering 1 GPMLow Gallons per minute of low flow showerhead Variable Default value = 1.5 or EDC Data Gathering 2 Average time of shower usage per person (minutes) Fixed 7.8 3 Npersons Average number of persons per household Variable Default SF=2.7 Default MF=1.8 Default unknown=2.6 Or EDC Data Gathering 4 Average number of showers per person per day Fixed 0.6 5 days/year Number of days per year Fixed 365 S/home Average number of showers in the home Variable Default SF=1.7 (89.6% of homes) Default MF=1.3 (10.4% of homes) Default unknown = 1.6 Or EDC Data Gathering 6 Tout Assumed temperature of water used by showerhead Fixed 101° F 7 Tin Assumed temperature of water entering house Fixed 55° F 7,8 UH Unit Conversion: 8.33BTU/(Gallons-°F) Fixed 8.33 Convention UE Unit Conversion: 1 kWh/3413 BTU Fixed 1/3413 Convention RE Recovery efficiency of electric water heater Fixed 0.98 9 FED Energy To Demand Factor Fixed 0.00008013 10 ISR In Service Rate Variable Variable EDC Data Gathering ELEC Percentage of homes with electric water heat Variable Default=43% Or EDC Data Gathering 11