| There are a lot of tankless water heater | | | | 1.Average energy to heat water to 110 oF is |
| manufactures claiming a wide range of savings | | | | 6.2 kW |
| on your next water heating bill. A quick | | | | |
| search on the web will show you a percent | | | | 2.Average daily usage is 1.5 hours |
| reduction of up 80%. | | | | |
| | | | 3.Daily power needed to heat the water to |
| However the question still exists: how much | | | | 110F is: 1.5 hours x 6.2 kW = 9.3 kWh |
| would you really save on your water heating | | | | |
| bill using a tankless water heater? | | | | 4.Annual costs to heat water using a tankless |
| | | | water heater is: 9.5 kWh/ day x 335 days/ |
| Most importantly what is the payback or ROI | | | | year x $0.11/kWh = $343 |
| of the average tankless water heater and how | | | | |
| does it compare to a traditional tank hot | | | | 5.Average annual idle cost for a tankless |
| water system? Let us try to answer these | | | | water heater: $17 |
| questions. | | | | |
| | | | So the total cost of heating water using a |
| Annual costs associated with water heaters of | | | | tankless water heater is $343 + $17 or $360. |
| any type are divided into 3 categories: | | | | |
| | | | What do these numbers mean? |
| 1.Energy costs to heat the water from its | | | | |
| incoming temperature to the desired | | | | 1.The percent annual savings using a tankless |
| temperature. | | | | water heater over a traditional tank system |
| | | | is 50% or $375 C |
| 2.Standby energy costs: in the case of | | | | |
| traditional tank heaters, standby cost is the | | | | 2.This amount ($375) is equal to the cost of |
| cost of the energy to keep the water hot in | | | | an average mid-size tankless water heater. |
| the tank all day. For a tankless water heater | | | | Please note: Installation costs were found to |
| standby cost is the cost of energy when the | | | | be comparable for both tank and tankless |
| tankless water heater is running idle | | | | systems, ~$150. |
| (minimal). | | | | |
| | | | 3.In addition there is the potential for tax |
| 3.Installation costs: This is the cost to | | | | credits for any tankless water heater. |
| install the heater and all its piping system | | | | (Please visit for more information ) |
| | | | |
| So let us examine these costs for both | | | | 4.Given the longer life of a tankless water |
| traditional tank heaters and tankless water | | | | heater at 22 years versus a tank system 10 |
| heaters in detail. | | | | years there is the potential of saving over |
| | | | $4,000 over the long term. |
| Average Annual Traditional Tank Heater Costs | | | | |
| | | | Notes: |
| 1.Annual hot water demand: 87 gallons / day | | | | |
| x 335 days / year = 29,145 gallons/ year. | | | | 1.The incoming water temperature from which |
| | | | the department of energy (DOE) calculations |
| 2.Power to heat up 1 gallon of water from 57 | | | | are made, has been established at 57F. In |
| oF to 110 oF according to the multi-housing | | | | many parts of the U.S. one does not normally |
| laundry association is 0.2 kWh | | | | experience inlet temperatures this cost year |
| | | | round however, we used 57F as our inlet |
| 3.The annual power requirement of heating the | | | | temperature. 110 oF is the average household |
| water from 57 oF to 110 oF for an American | | | | hot water operating temperature. This |
| household is: 29,145 gallons/ year x 0.2 kWh/ | | | | translates to 53 degrees of temperature rise |
| gallon = 5,900 kWh/ year | | | | for both tank and tankless water heating |
| | | | systems |
| 4.The cost of 5,900 kWh: 5,900 kWh/ year x | | | | |
| $0.11/ kWh = $649/ year | | | | 2.According to the U.S. department of energy |
| | | | (July 2006) the average American household |
| 5.The cost to keep one gallon of water hot is | | | | consumes 87 gallons of hot water per day |
| $0.003 | | | | |
| | | | 3.Average cost of electricity for the United |
| So, the cost to keep 21,145 gallons of water | | | | States at the time of writing, is $0.11 kWh, |
| hot (standby): 21,945 gallons/ year x $0.003/ | | | | as per the DOE. |
| gallon = $87 | | | | |
| | | | Disclaimer: The information on the system, |
| So the total annual cost of heating water | | | | product or material presented herein is |
| using a traditional tank system is $649 + $85 | | | | provided for informational purposes only. |
| or $736. | | | | Please ensure that you consult a qualified |
| | | | technician prior to installing a tankless |
| Average annual tankless water heater costs | | | | water heater or any suggestions put forward |
| | | | by e-Smart Living. |