Tom,
You said,
>You did not factor in the energy used to heat the water which is a huge cost for some and which would have been far greater with the GE than your FL.
While I'm certainly in agreement in regards to this, I deliberately left it out, only because I thought that the difference was somewhat negligable.
Even so, you have me thinking now.. Forgive me if my math is out...
My water heater holds 151.4 Litres. Using the formula,
Q = mass x specific heat x delta T
With delta T being 55 degrees C (Input water being 5 C and output water being heated to 60 C) and the specific heat is 4.186 Joules/gram...
For the metric impaired, 1 Litre of water = 1 Kilogram.
Thereby, 151,400 g x 4.186 J x 55 C = 34,856,822 Joules.
Natural gas in my area right now is $3.69 per Gigajoule including fees.
Now, if I then assume that the gas burner on my water heater is 85 percent efficent, it would take about 41,008,025 Joules to heat that water.
If I were to completely drain the tank and refill it with cold water and then heat it, I figure it would cost about $0.15 in natural gas to heat the entire tank up to 60 C or about 140 F. (That's easier than figuring out a percentage.)
Thereby, my GE top loader, had I used a hot water cycle, would cost about 9 cents in Natural gas, while the Huebsch would cost 3 cents instead, a savings of 6 cents.
So, even over 50 loads in a year, the cost of the extra hot water a Non-HE top loader would use over a HE front loader would be pretty close to $3.00.
So, the total savings is $16 instead of $13 per year.
The conversion is easy in this case because I'm using natural gas, but I'm wondering how much more expensive electric water heaters would cost to heat the water.
I'm thinking.. 1 kWh = 3,600,000 Joules.. stepping back, with 85 percent efficency (I'm just pulling a number out of my rear end on this) is 11.391 kWh.
Where I live, 1 kWh is $0.089, so thereby heating an entire tank of the same water with electricity instead of natural gas would cost $1.01 instead of $0.15.
So, using the same machines, a hot water load costs $0.60 to heat, while in the Huebsch it would cost $0.18 .. a cost savings of 42 cents per load. For 50 loads in a year, the cost savings would be a much more considerable $21.00 instead of $3.00.
So, instead the total savings add up to $34.00 a year, which is more considerable, but still sounds like a small amount to me. That's about $2.83/mo.
Does this math sound right? Am I missing something here?