aerator savings calculations
Step 1 find cost per gallon$2.80 fresh water + $2.80 waste water = $5.60 per 1000 gallons $5.60 / 1000 = $0.0056 per gallon |
Step 2 find daily gallon usage13.2 mins x 2.5 gallons per min = 33 13.2 mins x 1.5 gallons per min = 19.8 |
Step 3 find the difference in gallons used33 - 19.8 = 13.2 gallons savings |
Step 4 find the cost savings in water13.2 x $0.0056 = $0.0739 water savings per day |
Step 5 find the number of heated gallons of water33 x 20% = 6.6 gallons of heated water per day 19.8 x 20% = 3.96 gallons of heated water per day |
Step 6 find the number of degrees of heating water140 water heater temp - 57.5 cold water temp = 82.5 degrees |
Step 7 multiply the number of degrees by the 8.337 BTUs it takes to heat one gallon of water one degree8.337 BTUs x 82.5 degrees to raise by = 687.8025 BTUs to heat 1 gallon to desired temp |
Step 8 take into account the hot water heater efficiency687.8025 BTUs / 85% = 809.1794 |
Step 9 multiply your efficiency adjusted BTUs by the number of gallons to be heated809.1794 BTUs x 6.6 gallons to heat = 5,340.5840 BTUs per day 809.1794 BTUs x 3.96 gallons to heat = 3,204.3504 BTUs per day |
Step 10 convert BTUs to therms5,340.5840 / 100,000 = 0.0534 therms per day 3,204.3504 / 100,000 = 0.032 therms per day |
Step 11 covert therms to kilowatt hours for electric water heaters0.0534 therms per day x 29.3071 KWh per therm = 1.565 KWh per day 0.032 therms per day x 29.3071 KWh per therm = 0.9378 KWh per day |
Step 12 find the cost of heating water with electric1.565 daily KWh use * $0.118 cost per KWh = $0.1847 per day cost 0.9378 daily KWh use * $0.118 cost per KWh = $0.1107 per day cost |
Step 13 find the difference in electric savings$0.1847 - $0.1107 = $0.0740 electric savings per day |
Step 14 add the water and electric savings$0.0740 daily electric savings + $0.0739 daily water savings = $0.1479 daily savings |
Step 15 find yearly and lifetime savings in dollars with electric$0.1479 x 365 = $53.99 yearly savings with electric $53.99 x 3 year estimated life = $161.97 estimated lifetime savings with electric |
Step 16 find yearly and lifetime electric savings1.565 - 0.9378 = 0.6272 daily KWh savings 0.6272 x 365 = 228.9 yearly KWh savings 228.9 x 3 year estimated life = 687 lifetime KWh savings |
Step 17 find yearly and lifetime water savings13.2 gallons daily water savings x 365 = 4,818 gallons yearly water savings 4,818 x 3 year estimated life = 14,454 lifetime water savings $0.0739 daily water savings x 365 days = $26.98 yearly water savings |