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On Sep 14, 11:23?pm, ransley wrote:
On Sep 14, 9:50?pm, " wrote:

On Sep 14, 10:23 pm, Tony Hwang wrote:

Hi,
Under same condition, only comparing tank life, which one would last
longer, natural gas one or electric one?

electrics tend to last longer.

the downside is much lower performance for electric and higher
operating cost

If cost per btu of both fuels is the same, or nearly, this is not
true. Electric is near 99% efficent, your average gas tank sold is
near 50-65% efficent, with the high end on condensing Ng around 80-85%
total efficency, known and rated as EF. Recovery or performance is
what you buy and need. Gas also loose efficency every year due to
scale buildup that does not affect electric units. And how many ever
have their burner checked to be sure its burning right. A premium
could be paid for electricty and an electric could still be cheaper to
run. Every areas fuel and electric costs are different so run your own
numbers.

obviously you have never replaced a scale covered electric heater
element

Scale buildup effects gas heaters differently then it does electric. Scale
slows down the heat transfer into the water. The hot gas goes by and if it
doesn't transfer right then and there into the water, the hot gas is
exhausted and the heat energy is vented into the atmosphere. A little bit of
scale can make a big difference, and efficiency goes out the window.

With electric heaters, scale buildup on the element slows down the heat
transfer from the element into the water. The element gets hotter which
increases it's resistance, and less current flows. However, almost all of
the heat still makes it into the water - where else is it going to go? Even
with old scale coated elements, most of the heat goes into the water and
efficiency remains very high. You don't waste electricity, you don't loose
efficiency, you just don't get your water heated as fast.