40 gal just not enough: Replacing water heater for 2400 sq home. Family of 2 adults + 2 children

Re: 40 gal just not enough: Replacing water heater for 2400 sq home. Family of 2 adults + 2 children

Thomas G. Marshall wrote:
> Ok, our 40 gal gas water heater is failing. About 10 years old, which I
> hear is ok.
>
> But every time I talk to someone about their 40 gal water heater, they all
> complain that they run out of hot water (comparable size homes and kids).
>
> Bur our builder (and all builder's we spoke to when looking to build)
> *insist* that 40 gallons is enough.
>
> But we were always worried about running the wash or dishwasher before
> showering, or two long showers would result in the 2nd losing water.
> Complete with those water saving disks etc.
>
> 1. Is 80 gallons overkill? Perhaps I'm reacting viscerally.
>
> 2. Am I going to notice a large gas usage increase?
>
> 3. Are there rules in place limiting the water tank sizes?
>
> 4. Are there any particular brands to look for or stay away from?
>
> I'm sorry for the barrage of questions.
>
>
>
>
Oil fired tankless is the way to go. All the hot water you want, never
run out and it stops running just as soon as you cut off the faucet.
I know because I had one.

--
Blattus Slafaly ? 3 :) 7/8

Re: 40 gal just not enough: Replacing water heater for 2400 sq home. Family of 2 adults + 2 children

On 04/07/08 01:24 pm Thomas G. Marshall wrote:

> Ok, our 40 gal gas water heater is failing. About 10 years old, which I
> hear is ok.
>
> But every time I talk to someone about their 40 gal water heater, they all
> complain that they run out of hot water (comparable size homes and kids).
>
> Bur our builder (and all builder's we spoke to when looking to build)
> *insist* that 40 gallons is enough.
>
> But we were always worried about running the wash or dishwasher before
> showering, or two long showers would result in the 2nd losing water.
> Complete with those water saving disks etc.
>
> 1. Is 80 gallons overkill? Perhaps I'm reacting viscerally.
>
> 2. Am I going to notice a large gas usage increase?
>
> 3. Are there rules in place limiting the water tank sizes?
>
> 4. Are there any particular brands to look for or stay away from?
>
> I'm sorry for the barrage of questions.


ISTR that the standard capacity in Australia was 60 gallons, with 80
gallons as a common upgrade -- and remember that these are "Real
gallons," each consisting of eight 20-ounce pints. The one already in
the house we bought in the US Midwest, however, is 50 (mini-)gallons.

I don't know how the various brands rate here in the USA, but Rheem was
common in Australia. When we built our house in Australia, however, we
used a local (I mean really local, not marketed outside that State,
AFAIK) brand that had a 25-yr warranty. One day I was wandering through
a shopping mall and got accosted by the salesdroid at a Rheem booth who
asked me how old my water heater was; when I told him "12 years," he
said, "Oh, so you'll be needing a new one soon"; when I told him the
brand I had, he said, "Oh, then you won't be needing a new one for a
long time yet." IOW, widely advertised brands aren't always the best.

Perce

Re: 40 gal just not enough: Replacing water heater for 2400 sq home. Family of 2 adults + 2 children

On Apr 7, 5:45 pm, "Percival P. Cassidy" <nob...@notmyISP,net > wrote:
> On 04/07/08 01:24 pm Thomas G. Marshall wrote:
>
>
>
>
>
> > Ok, our 40 gal gas water heater is failing.  About 10 years old, which I
> > hear is ok.
>
> > But every time I talk to someone about their 40 gal water heater, they all
> > complain that they run out of hot water (comparable size homes and kids).
>
> > Bur our builder (and all builder's we spoke to when looking to build)
> > *insist* that 40 gallons is enough.
>
> > But we were always worried about running the wash or dishwasher before
> > showering, or two long showers would result in the 2nd losing water.
> > Complete with those water saving disks etc.
>
> > 1. Is 80 gallons overkill?  Perhaps I'm reacting viscerally.
>
> > 2. Am I going to notice a large gas usage increase?
>
> > 3. Are there rules in place limiting the water tank sizes?
>
> > 4. Are there any particular brands to look for or stay away from?
>
> > I'm sorry for the barrage of questions.
>
> ISTR that the standard capacity in Australia was 60 gallons, with 80
> gallons as a common upgrade -- and remember that these are "Real
> gallons," each consisting of eight 20-ounce pints. The one already in
> the house we bought in the US Midwest, however, is 50 (mini-)gallons.
>
> I don't know how the various brands rate here in the USA, but Rheem was
> common in Australia. When we built our house in Australia, however, we
> used a local (I mean really local, not marketed outside that State,
> AFAIK) brand that had a 25-yr warranty. One day I was wandering through
> a shopping mall and got accosted by the salesdroid at a Rheem booth who
> asked me how old my water heater was; when I told him "12 years," he
> said, "Oh, so you'll be needing a new one soon"; when I told him the
> brand I had, he said, "Oh, then you won't be needing a new one for a
> long time yet." IOW, widely advertised brands aren't always the best.
>
> Perce- Hide quoted text -
>
> - Show quoted text -



Before concluding that 40gallons is the problem, I'd check the shower
heads and flow rates. You may find that reducing the shower flow a
bit means you will have enough hot water from a 40 and save energy
too. Also, it's possible the existing one has some serious
problems. If it's full of sediment, has a broken dip tube, etc, it
may not be performing anywhere near what a new one is capable of.

Check the first hour rating on the ones you are considering. That'a
a good indicator of how much water they can supply in typical high
demand hour.

If you do decide to go larger, I'd think a 50 with a good first hour
rating would probably be enough for most families of 4.

As others have pointed out, you can also consider tankless. Main
issues there are unit and installation cost, which can be higher
depending on existing gas lines. The TL needs a much larger gas
supply.

Re: 40 gal just not enough: Replacing water heater for 2400 sq home. Family of 2 adults + 2 children

regular 40 gallon hot water tank BTU vary anywhere from 34,000 btu to
75,000 btu. the higher the BTU the better.

Because we ran out occasionally we went from a 34,000 BTU 40 gallon
tank to a 75,000 BTU 50 gallon tank. I wanted a 75 gallon tank but it
wouldnt fit the available space between toilet and furnace.

Tankless tends to be a hot topic here........ from inadquate heat, cool showers if you live in areas that freeze in the winter, no hot
water at all in a power failure, if the tankless uses line voltage to
operate, no hot water with valve just open a little, super expensive
install, needing new gas line and occasionally a new meter. teenagers
given unlimited hot water might live in the shower. expensive service,
tankless are complex and require occasional service, standby losses in
current tanks is actually low, and stanby losses help heat your home
in the winter, so most of the heat isnt really lost. life is full of
sytandby losses, tv, cable boxes clocks etc etc. anything that draws
power when not in use is a standby loss......

your old tank is probably full of sludge decreasing its hot water
ability.

a new tankless will cost a fortune.......... 3 to 4 times a standard
tank which is highly reliable.

so lets talk tanks

upgrade from your old 40 gallon probably 40,000 btu to a 75 or 80
gallon 75,000 btu will likely give you about 4 times or more your
current hot water capacity. and in its life probably never need
service

you double the gallon capacity and double the burners BTU rating,
roughly 4 times the hot water.

no more cold showers:)

Re: 40 gal just not enough: Replacing water heater for 2400 sq home. Family of 2 adults + 2 children

On Apr 7, 7:11 pm, "hall...@aol,com " <hall...@aol,com > wrote:
> regular 40 gallon hot water tank BTU vary anywhere from 34,000 btu to
> 75,000 btu. the higher the BTU the better.
>
> Because we ran out occasionally we went from a 34,000 BTU 40 gallon
> tank to a 75,000 BTU 50 gallon tank. I wanted a 75 gallon tank but it
> wouldnt fit the available space between toilet and furnace.
>
> Tankless tends to be a hot topic here........ from inadquate heat, =
> cool showers if you live in areas that freeze in the winter, no hot
> water at all in a power failure, if the tankless uses line voltage to
> operate, no hot water with valve just open a little, super expensive
> install, needing new gas line and occasionally a new meter. teenagers
> given unlimited hot water might live in the shower. expensive service,
> tankless are complex and require occasional service, standby losses in
> current tanks is actually low, and stanby losses help heat your home
> in the winter, so most of the heat isnt really lost. life is full of
> sytandby losses, tv, cable boxes clocks etc etc. anything that draws
> power when not in use is a standby loss......
>
> your old tank is probably full of sludge decreasing its hot water
> ability.
>
> a new tankless will cost a fortune.......... 3 to 4 times a standard
> tank which is highly reliable.
>
> so lets talk tanks
>
> upgrade from your old 40 gallon probably 40,000 btu to a 75 or 80
> gallon 75,000 btu will likely give you about 4 times or more your
> current hot water capacity. and in its life probably never need
> service
>
> you double the gallon capacity and double the burners BTU rating,
> roughly 4 times the hot water.
>
> no more cold showers:)

Here we go again the same missinformation, with 90-100f temp rise
offered you cant have a cold shower, I cant shower at over 106f but my
unit takes 35f water and heats it to 125 if I was to be wastefull.

Mine has battery ignition and regular vent-No A.C. But I have a
generator for my home for heat.

It took me 5 hrs to install, but I guess thats "super expensive" for
you. I put in 3/4 gas but that was only 1 hr work, again easy and
cheap, my meter is original.

Tankless require no "service" but tanks are supposed to be flushed
every year.

20% of your loss is waste-up the chimney and out, of no benefit to
anyone but your gas supplier since true overall efficency is near
50-60% in " Energy Factor" proven ratings

I paid about 500$ for a Bosch 117000btu unit, I get a FOUR year
payback, I hardly see the 3-4x cost of waste, I see I am saving money

Tank, loose efficency every year due yo scale settling over the
burner, just as my last tank had over a foot of scale at the bottom,
its efficency was probably reduced 20-40%, tankless dont do that, and
its easy to pour lime away through mine. You cant do that with a tank.

Re: 40 gal just not enough: Replacing water heater for 2400 sq home. Family of 2 adults + 2 children

=2E

>
> Here we go again the same missinformation, with 90-100f temp rise
> offered you cant have a cold shower, I cant shower at over 106f but my
> unit takes 35f water and heats it to 125 if I was to be wastefull.
>
> =EF=BF=BDMine has battery ignition and regular vent-No A.C. But I have a
> generator for my home for heat.
>
> It took me 5 hrs to install, but I guess thats "super expensive" for
> you. I put in 3/4 gas but that was only 1 hr work, again easy and
> cheap, my meter is original.
>
> Tankless require no "service" but tanks are supposed to be flushed
> every year.
>
> 20% of your loss is waste-up the chimney and out, of no benefit to
> anyone but your gas supplier since true overall efficency is near
> 50-60% in " Energy Factor" proven ratings
>
> I paid about 500$ for a Bosch 117000btu unit, I get a FOUR year
> payback, I hardly see the 3-4x cost of waste, I see I am saving money
>
> Tank, loose efficency every year due yo scale settling over the
> burner, just as my last tank had over a foot of scale at the bottom,
> its efficency was probably reduced 20-40%, tankless dont do that, and
> its easy to pour lime away through mine. You cant do that with a tank.- Hi=
de quoted text -
>
> - Show quoted text -

you said above

"Tankless require no "service" but tanks are supposed to be flushed
every year"

then talk of pouring lime away thru yours

"tankless dont do that, and its easy to pour lime away through mine.
""

frankly draing a little bit of water out of the bottom drain valve is
way easier than taking the plumbing apart to pour in lime away, which
isnt cheap, and then flush it out somehow.

plus you always talk of 20% going up the chimney as standby loss but
refuse to supply a link to verify that:(

people who go tankless have spent so much money they will have to
convince themselves it was a good move........

Re: 40 gal just not enough: Replacing water heater for 2400 sq home. Family of 2 adults + 2 children

Kind of like the boys with the high dollar K$N filters on their trucks.
.... They'll always tell you they run better when they know good and well
it made no difference whatsoever...


s


<hallerb@aol,com > wrote in message
news:f685f587-6c59-425e-bda2-5f44b0611268@d1g2000hsg.googlegroups,com ...

people who go tankless have spent so much money they will have to
convince themselves it was a good move........

Re: 40 gal just not enough: Replacing water heater for 2400 sq home. Family of 2 adults + 2 children

On Apr 8, 10:39 am, "S. Barker" <ichasetra...@coldmail,com > wrote:
> Kind of like the boys with the high dollar K$N filters on their trucks.
> ....   They'll always tell you they run better when they know good and well
> it made no difference whatsoever...
>
> s
>
> <hall...@aol,com > wrote in message
>
> news:f685f587-6c59-425e-bda2-5f44b0611268@d1g2000hsg.googlegroups,com ...
>
> people who go tankless have spent so much money they will have to
> convince themselves it was a good move........

I don't think that's fair. Ransley says he's actually bought one for
$500 and installed it himself relatively easy. And he's happy with
the results. I think his opinion is worth more than most here most
of whom don't have one and just sling mud. Especially those that
continue to spout misleading information, like "The heat loss from a
tank unit helps heat your home in the winter." It's been pointed out
repeatidly that much of the waste heat in a gas tank unit goes up the
flue. And the heat that escapes the sides of the tank only helps heat
the house if it happens to be in the living space, which isn't where
most are located. And then, in summer, the heat is still added to
the house and if you have AC as most do, then you're paying to remove
that heat. Yet, this same sad misinformation continues.

Re: 40 gal just not enough: Replacing water heater for 2400 sq home. Family of 2 adults + 2 childre

On Tue, 8 Apr 2008 08:26:00 -0700 (PDT), trader4@optonline,net wrote:

>I don't think that's fair. Ransley says he's actually bought one for
>$500 and installed it himself relatively easy. And he's happy with
>the results. I think his opinion is worth more than most here most
>of whom don't have one and just sling mud. Especially those that
>continue to spout misleading information, like "The heat loss from a
>tank unit helps heat your home in the winter." It's been pointed out
>repeatidly that much of the waste heat in a gas tank unit goes up the
>flue. And the heat that escapes the sides of the tank only helps heat
>the house if it happens to be in the living space, which isn't where
>most are located. And then, in summer, the heat is still added to
>the house and if you have AC as most do, then you're paying to remove
>that heat. Yet, this same sad misinformation continues.

The OP has an electric water heater and electric units do not have
stack related losses. The only loss is through the tank wall and these
losses are less than 1 kWh per day if the tank has an EF of 0.93 or
better (the new minimum standard is 0.91).

Secondly, if the tank is located inside a conditioned space any heat
loss through the wall *will* offset a portion of the home's space
heating demand. If the home is electrically heated the net loss is
effectively zero during the heating season and for those who heat with
oil, the losses could result in a net positive gain now that
residential fuel oil is more expensive than electricity in many parts
of the country.

With respect to air conditioning, a central air unit with a SEER of 10
would eliminate 2.94 kWh of heat for every 1.0 kWh consumed (the ratio
is 3.8 kWh to 1 for a 13 SEER unit). Thus, the additional a/c burden
for a 10 SEER model if tank losses are 0.91 kWh/day would be less than
10 kWh/month.

Cheers,
Paul

Re: 40 gal just not enough: Replacing water heater for 2400 sq home. Family of 2 adults + 2 children

On Apr 8, 11:57 am, Paul M. Eldridge <paul.eldri...@ns.sympatico.ca>
wrote:
> On Tue, 8 Apr 2008 08:26:00 -0700 (PDT), trad...@optonline,net wrote:
> >I don't think that's fair. Ransley says he's actually bought one for
> >$500 and installed it himself relatively easy. And he's happy with
> >the results. I think his opinion is worth more than most here most
> >of whom don't have one and just sling mud. Especially those that
> >continue to spout misleading information, like "The heat loss from a
> >tank unit helps heat your home in the winter." It's been pointed out
> >repeatidly that much of the waste heat in a gas tank unit goes up the
> >flue. And the heat that escapes the sides of the tank only helps heat
> >the house if it happens to be in the living space, which isn't where
> >most are located. And then, in summer, the heat is still added to
> >the house and if you have AC as most do, then you're paying to remove
> >that heat. Yet, this same sad misinformation continues.
>
> The OP has an electric water heater and electric units do not have
> stack related losses. The only loss is through the tank wall and these
> losses are less than 1 kWh per day if the tank has an EF of 0.93 or
> better (the new minimum standard is 0.91).

No he doesn't. OP wrote: "Ok, our 40 gal gas water heater is
failing. About 10 years old, which I
hear is ok."

> Secondly, if the tank is located inside a conditioned space any heat
> loss through the wall *will* offset a portion of the home's space
> heating demand. If the home is electrically heated the net loss is
> effectively zero during the heating season and for those who heat with
> oil, the losses could result in a net positive gain now that
> residential fuel oil is more expensive than electricity in many parts
> of the country.

Most of the water heat inefficiency goes up the flue, so do most of
the dollars. It's an odd argument to state that putting a heater
(waste heat from the water heater) in a location that you don't need
it, is a smart move. Maybe we should all go back to the huge ass
furnaces under the house with one central floor grate to heat the
home. Then none of the inefficiency is lost...unfortunately most of
the comfort is.

R

Re: 40 gal just not enough: Replacing water heater for 2400 sq home. Family of 2 adults + 2 children

On Apr 8, 11:57 am, Paul M. Eldridge <paul.eldri...@ns.sympatico.ca>
wrote:
> On Tue, 8 Apr 2008 08:26:00 -0700 (PDT), trad...@optonline,net wrote:
> >I don't think that's fair.   Ransley says he's actually bought one for
> >$500 and installed it himself relatively easy.  And he's happy with
> >the results.   I think his opinion is worth more than most here most
> >of whom don't have one and just sling mud.    Especially those that
> >continue to spout misleading information, like "The heat loss from a
> >tank unit helps heat your home in the winter."   It's been pointed out
> >repeatidly that much of the waste heat in a gas tank unit goes up the
> >flue.  And the heat that escapes the sides of the tank only helps heat
> >the house if it happens to be in the living space, which isn't where
> >most are located.     And then, in summer, the heat is still added to
> >the house and if you have AC as most do, then you're paying to remove
> >that heat.    Yet, this same sad misinformation continues.
>
> The OP has an electric water heater and electric units do not have
> stack related losses. The only loss is through the tank wall and these
> losses are less than 1 kWh per day if the tank has an EF of 0.93 or
> better (the new minimum standard is 0.91).

Yes, but that has nothing to do with much of the mis-information and
slams directed against tankless units. All I'm saying is Ransley
actually has one, paid $500 for it, installed it without too much
effort and says it works well for him. That's some actual data,
instead of speculation.

Also, the vast majority of tankless are not going to be compared to
electric water heaters, but instead to gas ones. That's because
almost everywhere, it's cheaper to heat water with gas than electric.
So, someone looking for a water heater with gas available, isn't going
to be looking at electric and then you do have the heat loss via flue.


>
> Secondly, if the tank is located inside a conditioned space any heat
> loss through the wall *will* offset a portion of the home's space
> heating demand.  If the home is electrically heated the net loss is
> effectively zero during the heating season and for those who heat with
> oil, the losses could result in a net positive gain now that
> residential fuel oil is more expensive than electricity in many parts
> of the country.
>
> With respect to air conditioning, a central air unit with a SEER of 10
> would eliminate 2.94 kWh of heat for every 1.0 kWh consumed (the ratio
> is 3.8 kWh to 1 for a 13 SEER unit).  Thus, the additional a/c burden
> for a 10 SEER model if tank losses are 0.91 kWh/day would be less than
> 10 kWh/month.
>
> Cheers,
> Paul

Yes, that's true, but as I already pointed out:


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.

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

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

Re: 40 gal just not enough: Replacing water heater for 2400 sq home. Family of 2 adults + 2 children


> 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.
>
> 2 - Most water heaters are not located in a conditioned space.
>
> 3 - In the grand scheme of things, this whole heat loss benefit is a
> nit.- Hide quoted text -
>
> - Show quoted text -- Hide quoted text -
>
> - Show quoted text -

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.

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....

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

Re: 40 gal just not enough: Replacing water heater for 2400 sq home. Family of 2 adults + 2 children

On Apr 8, 7:25 pm, "hall...@aol,com " <hall...@aol,com > 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/27578/Choosing a Domestic HotWater 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

Re: 40 gal just not enough: Replacing water heater for 2400 sq home. Family of 2 adults + 2 children

On 2008-04-08, hallerb@aol,com <hallerb@aol,com > wrote:

> 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....

Take a look at < http :// www .aceee.org/consumerguide/waterheating.htm>,
in particular the life-cycle costs comparison. This shows a typical
gas tank water heater has an energy factor of 0.60, and a typical gas
tankless has an energy factor of 0.80. The difference of 20%
represents the standby losses. Prior computations suggest that of
those standby losses, 7% represents the loss through the tank
insulation, and 13% represents the loss through the gas flue.

Cheers, Wayne

Re: 40 gal just not enough: Replacing water heater for 2400 sq home. Family of 2 adults + 2 children

On Apr 8, 8:10 pm, Wayne Whitney <whit...@post.harvard.edu> wrote:
> On 2008-04-08, hall...@aol,com <hall...@aol,com > wrote:
>
> > 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....
>
> Take a look at < http :// www .aceee.org/consumerguide/waterheating.htm>,
> in particular the life-cycle costs comparison.  This shows a typical
> gas tank water heater has an energy factor of 0.60, and a typical gas
> tankless has an energy factor of 0.80.  The difference of 20%
> represents the standby losses.  Prior computations suggest that of
> those standby losses, 7% represents the loss through the tank
> insulation, and 13% represents the loss through the gas flue.
>
> Cheers, Wayne

Hey Hallerb, here it is, read and learn.