On Apr 8, 7:25 pm, " wrote:
1 - At least one regular poster here continually mentions the winter
benefit of heat loss without regard to where the water heater is
located and totally ignores the AC impact in the summer.

Doing otherwise would be inconvenient for their argument.

2 - Most water heaters are not located in a conditioned space.

Well, it's semi-conditioned if you're in a heating climate and it's
winter.

3 - In the grand scheme of things, this whole heat loss benefit is a
nit.

It's not a nit, it's a distraction. It's also a semi-effective
distraction as only some of the heat radiates into the space and a
larger part goes up the chimney. I guess it would be akin to a
bumpkin earning thousands a month with their new found fame and
fortune and being thrilled, when they should be earning far more if
their business manager wasn't robbing them blind. It's good, but it
could be a lot better.

most water heaters are in basements, heat rises, so standby losses
help heat your home. or in a closet on a living floor, again standby
loss heats its suroundings, thats where you live.

Heat doesn't rise, hot air does. As Bud Abbott would say, "What's
holding you down?" =:O
Heat radiates and basement walls are a notorious heat sink in cold
climates. I think that heat should be applied in the proper amount
where it's needed, and not in a basement with hopes that it will find
its way to the correct location.

again please post a link that says 20% go up the chimney........
please a link....... please........ all i see is someone stating it
must be....

You mean like this one?
http://www.hpac.com/Issue/Article/27...o****er_System
An excerpt: "Energy efficiency is another problem with a typical
direct-fired water heater. A standard water heater is rated at about
84-percent steady state efficiency. That means that while the fire is
on, 84 percent of the heat from the fire enters the tank, while 16
percent of the heat goes up the chimney. That sounds pretty good, but
a water heater is not a steady state device: the fire turns on and
off. While the heater is off heat is still going up the chimney.

The annual fuel utilization efficiency (AFUE) rating of a typical
water heater is much lower, in the range of 70 percent for a 40-gal.
heater and dropping to 51 percent for a 75-gal. heater. An AFUE of 51
percent means that 51 percent of the heat in the fuel leaves the
heater by going out the hot water pipe. Except for a little heat lost
through the jacket of the heater, the rest goes up the chimney. So
while about 16 percent of the heat goes up the chimney while the fire
is burning, about another 15 to 35 percent, called "standby loss" goes
out the chimney while the fire is not burning."

Some of the Tagaki tankless heaters have EFs in the low 90s...

since the cost beween a regular tank and a tankless can easily be a
grand, that $ could be spent for added insulation and weatherstripping

There's no doubt that there are other ways to save energy and that
your average house could benefit, but we're discussing the relative
merits of tank v. tankless and not where someone should spend their
money. That decision is best left to the individual, no?

The thing that kills me is that the $300 federal tax credit for high
EF water heaters just expired in December - good timing! I wonder how
long it will be until they come up with some new credit program?

R