Over the last few days I have read several articles recommending that you turn your water heater off until a half hour before you want to shower as a means of cutting your electric bill. If you follow their advice your electric bill will actually go up instead of down because it takes more energy to bring a tank of cold water up to temperature then it takes to maintain the temperature after the initial heating. For a family of four the cost of operating a high-efficiency electric hot water heater is approximately $36 per month. Even if the same family had an older minimum efficient electric water heater the cost of running it all the time would only rise to around $38 per month. If you really want to take a bite out of your electric bill have an electric heat pump hot water heater installed. With an operating efficiency of 2.20 your monthly operating cost will drop to approximately $16 per month. The table below tells the whole story.
Hot Water Heater Comparison Chart
|
Water Heater Type |
Efficiency (EF) |
Installed Cost1 |
Yearly Energy Cost2 |
Life (Years) |
Total Cost (Over 13 Year Period3) |
|
Conventional gas storage types |
0.60 |
$850 |
$350 |
13 |
$5, 394 |
|
High-efficiency gas storage type |
0.65 |
$1,025 |
$323 |
13 |
$5, 220
|
|
Condensing gas storage type |
0.86 |
$2,000 |
$244 |
13 |
$5, 170 |
|
Conventional oil-fired storage |
0.55 |
$1, 400 |
$654 |
8 |
$11, 299 |
|
Minimum efficiency electric storage |
0.90 |
$750 |
$463 |
13 |
$6, 769 |
|
High-efficiency electric storage |
0.95 |
$800 |
$439 |
13 |
$6, 528 |
|
Demand Gas (No Pilot) |
0.80 |
$1, 600 |
$262 |
20 |
$5, 008 |
|
Electric heat pump water heaters |
2.20 |
$1, 660 |
$190 |
13 |
$4, 125 |
|
Solar with electric backup |
1.20 |
$4, 800 |
$175 |
20 |
$7, 072 |
1. The installed costs include cost of heater and average cost of labor to have it installed.
2. The yearly operating cost is based on the amount of hot water used by a family of four with the cost of energy based on 9.5₵/kWh for electricity, $1.40/therm for gas and $2.40/gallon for oil.
3. Future operating costs does not take into consideration inflation.
How do heat pump hot water heaters work
Conventional electric hot water heaters use two nichrome heating elements to heat the water to the desired temperature. These elements typically generate around 5500 Watts that is transmitted through conduction to the water. Heat pump hot water heater work like the heat pump you use to heat and cool your home by moving heat from one area to another instead of consuming large amounts of energy to generate heat on its own. You can also think of a heat pump hot water heater as a refrigerator working backwards. A refrigerator transfers heat from inside the refrigerator to the ambient air surrounding it, a heat pump hot water heater transfers heat from the ambient air surrounding the hot water heater to the water inside the tank.
Is a heat pump hot water heater right for you
A heat pump hot water heater will really save you money in the long run but there are a few negative aspects to using one and I would be remiss if I didn’t point them out.
· They must be installed in an area where the temperature can be maintained between 40° and 90° Fahrenheit all year long. An ideal location is near a furnace.
· They must be installed in an area of at least 1, 000 FT3 which is a space roughly 10FT X 13FT X 8FT in size. Because of this they don’t work too well with manufactured home because of space limitations.
· They have a long recycle time being able to heat water at the average rate of 15 gallons per hours so it will take approximately 3 hours to bring a 50 gallon hot water tank to the desired temperature.
· The initial installation cost is high at an average of $1, 660
· It’s not a project that the average DIYer can do because you are dealing with compressors, evaporators, compressors and refrigerants.
