DIYbanter - View Single Post - Can and LED floodlight possibly be as bright as a real floodlight?

Jerry Peters

In sci.electronics.repair Jeff Liebermann wrote:
On Fri, 17 Oct 2014 18:44:12 GMT, (Scott Lurndal)
wrote:

Jeff Liebermann writes:
On Fri, 17 Oct 2014 11:45:50 -0400, micky
wrote:
Also, if there were a soft plastic inside liner, I
would expect it to melt from the heat of gas flame at the bottom.

Have you never boiled water in a styrofoam cup over an open flame?

Yes. It requires a heat spreader between the cup and the flame. Apply
the flame directly and the hot spot will burn a hole in the styrofoam.

One can. The water keeps the temperature of the foam below its
melting point.

True. However, a gas water heater has to deal with stratification,
where the water is much hotter near the flame than near the tank
outlet. I couldn't determine how much of a temperature difference by
Googling. You're probably correct that it won't melt if it's decent
plastic, but I'm still suspicious. Unless secured to the steel tank,
it might soften, warp, bend, buckle, or otherwise provide an excuse
for water to get to the steel. From there, it's only the anode rod
that protects the steel tank from corrosion.

ALso plastic doesn't conduct heat all that well, leading to an
inefficient WH. Also a gas HWH has a pretty powerful burner, mine's
rated at 40,000 BTU/hour input. I suspect you suspicions about the
plastic buckling/warping and separating from the steel tank are
correct.