Dan Rather did tell the truth about one thing, that is why he got kicked
out.Nowadays, he is an editor at www.hd.net
I never read Consumers Reports.
cuhulin

On Sun, 10 Feb 2008 21:20:35 -0700, Rick Blaine wrote:
Heating less water costs less, even with equally efficient heaters.
Sigh. Absolutely true and totally meaningless within the context of this
discussion.
Hint: Direct energy cost is based on _use_ and efficiency, not _capacity_ and
efficiency.

It turns out Rick is right.

The size of the home water heater (e.g., 40 gallons, 50 gallons, etc.) is
nearly meaningless, as is the warranty period.

The only way the tank size plays any role in the selection process for
purely physical reasons. Why? Because both the EF and the FHR already take
into account the size of the holding tank so there is no need to even
bother to look at tank size (other than for purely physical reasons).

Likewise, the warranty is always less than the average lifetime of a home
water heater, which, at 13 years, is vastly greater than the 1-year labor
warrantees all the heaters I looked at (from Sears, Lowes, and Home Depot)
provided. (Note: The 12yr/9yr/6yr/etc. warranty figures often quoted by
Sears/Lowes/HomeDepot are for PARTS! Not labor).

Thanks everyone for enlightening me ... If I didn't know better, I'd buy by
the size of the tank and the warranty but now I know they are meaningless
figures. The manufacturer WANTS you to look there but in reality, the
truthy lies in the FHV, EF, and cost/therm.

I didn't realize you guys knew so much about home water heaters ... but I'm
glad you do. In only two days, I was able to take my knowledge level, with
your help, from absolutely nothing to being able make basic lifetime cost
comparisons given any two home heaters.

Thanks!

Donna

On Wed, 13 Feb 2008 08:13:09 GMT, James Sweet wrote:
It's really easy to take the cost shown on the sticker and extrapolate the
actual cost in your area. Cost per year on sticker/cost per therm on sticker
= X/Your cost per therm, solve for X.

Hi James,
You're right.

I guess what I meant was I can "solve for X" without looking at the
sticker. I can call Sears, Home Depot, or Lowes and just ask for FHR & ER
and, from that (and my known cost/therm), I can compare two heaters side by
side:

CHOICE A:
Sears 33154 (marketed as Kenmore but made by AO Smith) FHR=97 EF=0.63
(41,045 btu/0.63)($1.21106/therm * 1 therm/100,000 btu) x 365 = $288/year

CHOICE B:
Home Depot 183-717 (marketed as GE but made by Rheem) FHR=80 EF=0.58
(41,045 btu/0.58)($1.21106/therm * 1 therm/100,000 btu) x 365 = $313/year

But, you are right. If I were in the store, I could basically double the
annual operating costs shown and I'd be in the ballpark.

Thanks! We learned a lot in this thread, didn't we!

Donna

On Sun, 10 Feb 2008 21:49:53 -0700, Rick Blaine wrote:
What's the easiest way to compare heat leakage between two water heaters?

Look at the yellow energy label on the heaters. The annual cost to operate
printed there can be compared on different models.

Actually, since my cost per therm is far from the average used for those
stickers, the sticker numbers are innacurate in my situation.

The sticker numbers might work to roughly compare two models in performance
but they don't work to calculate the true payback period for two models.

For that, the math I've posted today should be sufficient (assuming the
calculations hold water under scrutiny of this esteemed group).

Donna

"Donna Ohl, Grady Volunteer Coordinator" wrote in
message t...
On Sun, 10 Feb 2008 21:49:53 -0700, Rick Blaine wrote:
What's the easiest way to compare heat leakage between two water heaters?

Look at the yellow energy label on the heaters. The annual cost to
operate
printed there can be compared on different models.

Actually, since my cost per therm is far from the average used for those
stickers, the sticker numbers are innacurate in my situation.

The sticker numbers might work to roughly compare two models in
performance
but they don't work to calculate the true payback period for two models.

For that, the math I've posted today should be sufficient (assuming the
calculations hold water under scrutiny of this esteemed group).

Donna

It's really easy to take the cost shown on the sticker and extrapolate the
actual cost in your area. Cost per year on sticker/cost per therm on sticker
= X/Your cost per therm, solve for X.

On Wed, 13 Feb 2008 08:13:09 GMT, James Sweet wrote:

It's really easy to take the cost shown on the sticker and extrapolate the
actual cost in your area. Cost per year on sticker/cost per therm on sticker
= X/Your cost per therm, solve for X.

Hi James,
In running your calculations, I realized the EF is NOT shown on the energy
sticker! But, it can be derived. Is my match below correct?

Given an EnergyGuide sticker that says:
"This Model Uses 240 therms/year".

I think we can calculate the ER.
Does this calculation look right to you?

240 therms/year * 1 year/41,045,000 btu * 100,000 btu/1 therm = .58

The part of the math that escapes me is why this calculation uses 1,000
times the BTUs per year than the previous calculations. Any idea?

Donna

A quick comment on warranty period and the AVERAGE home gas water heater
life.

The AVERAGE is exactly that: an average or mean calculation of the life for
all units shipped/sold. The real life span is affected by many things,
including the water quality/hardness (it consumes the anode quicker), the
temperature setting you select (hotter means it builds more internal
pressure and you get a shorter life) and the amount of hot water that you
use (more cycles of the burner mean a shorter life).

I am on my third gas HWH and purchased the house new in 1991. The first
heater lasted about 7 years and the second 6.5 years. I had a 7-year
warranty on the tank from Sears and they gave me a replacement free of
charge which has been in now for over 5 years. I believe that I will get a
longer life this time around since two of my children are no longer living
at home.

The bottom line here is that the warranty period may be important depending
on your circumstances. It is basically a cheap insurance policy that covers
only the cost of a replacement heater. For me, that was important since I
do the installation myself, but for someone hiring a plumber, the material
cost could easily be less than the labor and associated miscellaneous
expenses (permits).

Good luck in whatever you choose.

Bob

"Donna Ohl, Grady Volunteer Coordinator" wrote in
message . net...
On Sun, 10 Feb 2008 21:20:35 -0700, Rick Blaine wrote:
Heating less water costs less, even with equally efficient heaters.
Sigh. Absolutely true and totally meaningless within the context of this
discussion.
Hint: Direct energy cost is based on _use_ and efficiency, not _capacity_
and
efficiency.

It turns out Rick is right.

The size of the home water heater (e.g., 40 gallons, 50 gallons, etc.) is
nearly meaningless, as is the warranty period.

The only way the tank size plays any role in the selection process for
purely physical reasons. Why? Because both the EF and the FHR already take
into account the size of the holding tank so there is no need to even
bother to look at tank size (other than for purely physical reasons).

Likewise, the warranty is always less than the average lifetime of a home
water heater, which, at 13 years, is vastly greater than the 1-year labor
warrantees all the heaters I looked at (from Sears, Lowes, and Home Depot)
provided. (Note: The 12yr/9yr/6yr/etc. warranty figures often quoted by
Sears/Lowes/HomeDepot are for PARTS! Not labor).

Thanks everyone for enlightening me ... If I didn't know better, I'd buy
by
the size of the tank and the warranty but now I know they are meaningless
figures. The manufacturer WANTS you to look there but in reality, the
truthy lies in the FHV, EF, and cost/therm.

I didn't realize you guys knew so much about home water heaters ... but
I'm
glad you do. In only two days, I was able to take my knowledge level, with
your help, from absolutely nothing to being able make basic lifetime cost
comparisons given any two home heaters.

Thanks!

Donna

On Wed, 13 Feb 2008 08:34:00 -0800 (PST), wrote:
the warranty on high output tanks is 7 years. could of got a 12
year tank but I prefered more hot water over longer warranty which is
generally pro rated anyway and replacement usually based on list price
rather than sale price.

Just to be clear, my research indicates ALL warranties (at least all those
from Sears, Home Depot, and Lowes) are really only 1 year labor.

I don't know about you, but, it's not likely I'll be disconnecting my water
heater and bringing it to the manufacturer after that one year is up.

May I ask a "real" question?

Given installation is about the same price as the home water heater itself,
what do you get for that vaunted 12 year warranty after the first year?

Sure, they'll replace it for free ... but it costs as much to replace as it
did to buy so ... tell me please (I'm not being fascesious) ...

WHAT does the warranty *really* buy you after the first year is up?

Donna

"Donna Ohl, Grady Volunteer Coordinator" wrote in
message news
On Wed, 13 Feb 2008 08:34:00 -0800 (PST), wrote:
the warranty on high output tanks is 7 years. could of got a 12
year tank but I prefered more hot water over longer warranty which is
generally pro rated anyway and replacement usually based on list price
rather than sale price.

Just to be clear, my research indicates ALL warranties (at least all those
from Sears, Home Depot, and Lowes) are really only 1 year labor.

I don't know about you, but, it's not likely I'll be disconnecting my
water
heater and bringing it to the manufacturer after that one year is up.

May I ask a "real" question?

Given installation is about the same price as the home water heater
itself,
what do you get for that vaunted 12 year warranty after the first year?

Sure, they'll replace it for free ... but it costs as much to replace as
it
did to buy so ... tell me please (I'm not being fascesious) ...

WHAT does the warranty *really* buy you after the first year is up?

Donna



Well if I understand this right, when you buy the heater you pay for the
heater, plus you pay for the installation. For a warranty replacement you
pay for the installation, does that not save you the cost of the heater?

My line of thought is that a unit with a longer warranty is likely built
better, with better quality components, and thus likely to last longer.
Whether this is universally true I can't say, however last time I looked at
them, the 12 year warranty heaters did have a nicer fit & finish than the 6
year models, and the price difference was very small. I'll replace it myself
if it ever fails, and I'm sure it will outlast the warranty with the soft
water we have here, but if it's a higher quality unit I'm willing to pay for
that.

If you do self installation, like most of the audience on your target
newsgroups, then the warranty means a big deal. If you pay someone to
install, then it may not be as important, especially if the design,
materials, and construction quality is identical.

Bob

"Donna Ohl, Grady Volunteer Coordinator" wrote in
message news
Just to be clear, my research indicates ALL warranties (at least all those
from Sears, Home Depot, and Lowes) are really only 1 year labor.

I don't know about you, but, it's not likely I'll be disconnecting my
water
heater and bringing it to the manufacturer after that one year is up.

May I ask a "real" question?

Given installation is about the same price as the home water heater
itself,
what do you get for that vaunted 12 year warranty after the first year?

Sure, they'll replace it for free ... but it costs as much to replace as
it
did to buy so ... tell me please (I'm not being fascesious) ...

WHAT does the warranty *really* buy you after the first year is up?

Donna

"Bob Shuman" wrote in message
...
A quick comment on warranty period and the AVERAGE home gas water heater
life.

The AVERAGE is exactly that: an average or mean calculation of the life
for
all units shipped/sold. The real life span is affected by many things,
including the water quality/hardness (it consumes the anode quicker), the
temperature setting you select (hotter means it builds more internal
pressure and you get a shorter life) and the amount of hot water that you
use (more cycles of the burner mean a shorter life).

I am on my third gas HWH and purchased the house new in 1991. The first
heater lasted about 7 years and the second 6.5 years. I had a 7-year
warranty on the tank from Sears and they gave me a replacement free of
charge which has been in now for over 5 years. I believe that I will get
a
longer life this time around since two of my children are no longer living
at home.

The bottom line here is that the warranty period may be important
depending
on your circumstances. It is basically a cheap insurance policy that
covers
only the cost of a replacement heater. For me, that was important since I
do the installation myself, but for someone hiring a plumber, the material
cost could easily be less than the labor and associated miscellaneous
expenses (permits).

I think it matters no matter who does the installation - either way, you
didn't have pay for a new heater.

wrote in message
...

warrantys are sales tools, they rarely help the purchaser much. wheres
your original invoice?

You keep all of that stuff, and not just in case you ever need to invoke the
warranty - you keep it for tax or insurance purposes.

You keep this stuff in a file folder in a drawer - it takes a few second to
put it there when you buy something new. Or in the case of something like a
water heater, you put it in a plastic bag and tape it to the appliance.

"Donna Ohl, Grady Volunteer Coordinator" wrote in
message t...
On Sun, 10 Feb 2008 21:49:53 -0700, Rick Blaine wrote:
What's the easiest way to compare heat leakage between two water
heaters?

Look at the yellow energy label on the heaters. The annual cost to
operate
printed there can be compared on different models.

Actually, since my cost per therm is far from the average used for those
stickers, the sticker numbers are innacurate in my situation.

The labels show the estimated annual energy usage AND the estimated annual
cost, based on an average cost of fuel. Take the energy usage and multiply
by your own fuel cost assumptions.

The sticker numbers might work to roughly compare two models in
performance
but they don't work to calculate the true payback period for two models.

For that, the math I've posted today should be sufficient (assuming the
calculations hold water under scrutiny of this esteemed group).

I doubt that your calculations are "true" - in the way that you initially
didn't account for the time value of money, I didn't see that you took into
account the changing cost of fuel. What is today a $25.00 annual saving
could be a $50.00, $75.00, $100.00 (make your own assumptions) annual saving
a year or three down the line. Nor did you account for general inflation,
or even the normal tendency for people's income to rise over time - today's
annual payback might mean an hour or two of work a year, but assuming
constant fuel costs, it'll probably be less work time a year or two down the
line.

You can estimate payback periods only by making a cat's cradle of
assumptions.

Bob Shuman wrote:
A quick comment on warranty period and the AVERAGE home gas water heater
life.

The AVERAGE is exactly that: an average or mean calculation of the life for
all units shipped/sold. The real life span is affected by many things,
including the water quality/hardness (it consumes the anode quicker), the
temperature setting you select (hotter means it builds more internal
pressure and you get a shorter life) and the amount of hot water that you
use (more cycles of the burner mean a shorter life).

I am on my third gas HWH and purchased the house new in 1991. The first
heater lasted about 7 years and the second 6.5 years. I had a 7-year
warranty on the tank from Sears and they gave me a replacement free of
charge which has been in now for over 5 years. I believe that I will get a
longer life this time around since two of my children are no longer living
at home.


The gas water heater in my house was old when I bought the place in
1998...and it is still running fine. I think it is about twenty years
old - no leaks so far! And I had three teenagers living here for a
number of years...

John :-#)#

The bottom line here is that the warranty period may be important depending
on your circumstances. It is basically a cheap insurance policy that covers
only the cost of a replacement heater. For me, that was important since I
do the installation myself, but for someone hiring a plumber, the material
cost could easily be less than the labor and associated miscellaneous
expenses (permits).

Good luck in whatever you choose.

Bob

"Donna Ohl, Grady Volunteer Coordinator" wrote in
message . net...
On Sun, 10 Feb 2008 21:20:35 -0700, Rick Blaine wrote:
Heating less water costs less, even with equally efficient heaters.
Sigh. Absolutely true and totally meaningless within the context of this
discussion.
Hint: Direct energy cost is based on _use_ and efficiency, not _capacity_
and
efficiency.
It turns out Rick is right.

The size of the home water heater (e.g., 40 gallons, 50 gallons, etc.) is
nearly meaningless, as is the warranty period.

The only way the tank size plays any role in the selection process for
purely physical reasons. Why? Because both the EF and the FHR already take
into account the size of the holding tank so there is no need to even
bother to look at tank size (other than for purely physical reasons).

Likewise, the warranty is always less than the average lifetime of a home
water heater, which, at 13 years, is vastly greater than the 1-year labor
warrantees all the heaters I looked at (from Sears, Lowes, and Home Depot)
provided. (Note: The 12yr/9yr/6yr/etc. warranty figures often quoted by
Sears/Lowes/HomeDepot are for PARTS! Not labor).

Thanks everyone for enlightening me ... If I didn't know better, I'd buy
by
the size of the tank and the warranty but now I know they are meaningless
figures. The manufacturer WANTS you to look there but in reality, the
truthy lies in the FHV, EF, and cost/therm.

I didn't realize you guys knew so much about home water heaters ... but
I'm
glad you do. In only two days, I was able to take my knowledge level, with
your help, from absolutely nothing to being able make basic lifetime cost
comparisons given any two home heaters.

Thanks!

Donna




--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

In my case, it was not pro-rated. I was given a new gas HWH by Sears to
replace the one that developed the small leak within the 7-year tank rust
out warranty period. I did need to bring them the old tank though, which
was not an issue.

Bob

wrote in message
...
having only 1 heater leak before the warranty ran out, and as far as i
know its still a pro rata warranty....

number of installed months, vs number of warranteed months, gives a
percentage, thats then applied to a brand new similiar heater at full
list price

on that one heater the sale price was less than the pro rata price,
kinda mad i bought my new one somewhere else........

warrantys are sales tools, they rarely help the purchaser much. wheres
your original invoice? company like sears might no longer be in
business in 8 years.........

just look at all the retailers who have goine out of business over the
years.....

a warranty from builders square or hechinger isnt worth the paper its
written on........

the BTU # is from the manufacturer, they vary from under 30,000 BTU to
75,000 BTU on my current tank.

higher btus cost more to build, better stronger burner and heavier
tank to take the added heat.

On Wed, 13 Feb 2008 11:17:11 -0800 (PST), wrote:
What is this "magic" number of 41,045 BTU?

I think it's the assumed amount of BTUs an "average" household uses in a
day.

I'm sure there are math majors out there in the crowd who could tell us if
that assumption is true given the formulas previously provided.

Sears 33154 (marketed as Kenmore but made by AO Smith) FHR=97 EF=0.63
(41,045 btu/0.63)($1.21106/therm * 1 therm/100,000 btu) x 365 = $288/year

CHOICE B:
Home Depot 183-717 (marketed as GE but made by Rheem) FHR=80 EF=0.58
(41,045 btu/0.58)($1.21106/therm * 1 therm/100,000 btu) x 365 = $313/year


Are any mathematicians out there who can tell us the units on the 41,045?

On Wed, 13 Feb 2008 19:33:41 GMT, Bob Shuman wrote:
If you pay someone to install, then warranty may not be as important,

I've learned that I agree with you.
The warranty is for the fire-and-forget type of homeowner.
The one who doesn't flush twice yearly, who doesn't add the second anode,
who doesn't replace the anode after a few years, who doesn't add the ball
valve, etc.

Even then, the owner with the warranty has to bring the soaking wet heater
in the back of their car in to the manufacturer after their 1-year is up on
their supposed 12-year warranty - or else pay as much for the plumber to
visit ($400) as the heater cost in the first place ($400) to obtain the
'free' heater.

Some deal, that 12-year warranty!

Or am I reading it wrong?

On Wed, 13 Feb 2008 11:28:41 -0800 (PST), wrote:

What is this "magic" number 41.045 anyway?

I'm guessing it's the number of BTUs used in a day for the average
household.

(41,045 btu/0.63)($1.21106/therm * 1 therm/100,000 btu) x 365 = $288/year

If my assumption is correct, you can better estimate YOUR usage simply by
using the number of BTUs you normally use in a day.

Does that work out?

That is, do most people use up about 41,045 BTUs a day on their water
heater?

Donna Ohl, Grady Volunteer Coordinator wrote:
On Wed, 13 Feb 2008 19:33:41 GMT, Bob Shuman wrote:

If you pay someone to install, then warranty may not be as important,


I've learned that I agree with you.
The warranty is for the fire-and-forget type of homeowner.
The one who doesn't flush twice yearly, who doesn't add the second anode,
who doesn't replace the anode after a few years, who doesn't add the ball
valve, etc.

Even then, the owner with the warranty has to bring the soaking wet heater
in the back of their car in to the manufacturer after their 1-year is up on
their supposed 12-year warranty - or else pay as much for the plumber to
visit ($400) as the heater cost in the first place ($400) to obtain the
'free' heater.

Some deal, that 12-year warranty!

Or am I reading it wrong?

You're pretty much right, although you still might find that within a
particular model line there are some quality/efficiency/construction
differences between the 6-year and 12-year models. you'll have to
evaluate those on a case by case basis though.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

On Feb 16, 7:13�am, Nate Nagel wrote:
Donna Ohl, Grady Volunteer Coordinator wrote:





On Wed, 13 Feb 2008 19:33:41 GMT, Bob Shuman wrote:

If you pay someone to install, then warranty may not be as important,

I've learned that I agree with you.
The warranty is for the fire-and-forget type of homeowner.
The one who doesn't flush twice yearly, who doesn't add the second anode,
who doesn't replace the anode after a few years, who doesn't add the ball
valve, etc.

Even then, the owner with the warranty has to bring the soaking wet heater
in the back of their car in to the manufacturer after their 1-year is up on
their supposed 12-year warranty - or else pay as much for the plumber to
visit ($400) as the heater cost in the first place ($400) to obtain the
'free' heater.

Some deal, that 12-year warranty!

Or am I reading it wrong?

You're pretty much right, although you still might find that within a
particular model line there are some quality/efficiency/construction
differences between the 6-year and 12-year models. �you'll have to
evaluate those on a case by case basis though.

nate

--
replace "roosters" with "cox" to reply.http://members.cox.net/njnagel- Hide quoted text -

- Show quoted text -

more expensive heater tend to have better materials, like brass drain
valves rater than plastic ones. plastics only job is to drain once at
end of life.. helped a buddy his plastic valves stem snapped off
trying to open it.....

we pushed the heater over on its side, and drained thru the fill lines
and T&P valve

a full 50 gallon tank is heavy,,,,,

400 pounds of water and at least a couple hundred for tank

Call me dumb, or whatever,,,,, call me anything as long as it's time for
supper.
But, I still don't get it about having to pay money for a permit for a
water heater.Do you live in America? I used to email chit chat back and
forth with a married woman in Vilnius,Lithuania.Things are strange over
there.
cuhulin

On Wed, 13 Feb 2008 11:53:00 -0800 (PST), wrote:
On Wed, 13 Feb 2008 11:53:00 -0800 (PST), wrote:
But it still doesn't say where the "magic" 41,045 BTU comes from.

Whatever magic it is, googling for 41045 BTU gets *lots* of related PDFs!

Residential ACM Manual: Water Heating Calculation Method, page 8
http://www.energy.ca.gov/title24/200...ACM_APP_RG.PDF
The standard energy in the hot water delivered, 41,045 Btu/day.

Comments on Energy Star Ratings of Home Water Heaters, Page 5
http://www.energystar.gov/ia/partner...nergy_corp.pdf
Using the formula: 41,045 Btu/EF($/Btu)*365

ENERGY STAR Residential Water Heaters: Analysis, page 10
http://www.energystar.gov/ia/partner...iaAnalysis.pdf
Energy consumption estimated using the DOE test procedure.
Based on the following formula: (41,045 BTU/EF x 365)/100,000

LIFE CYCLE COSTS AND SAVINGS FOR WATER HEATING SYSTEMS, page 3
http://www1.eere.energy.gov/solar/us...info_sheet.pdf
The annual delivered energy is 14.98 MMBtu (41045 Btu/day).

OPERATING GUIDELINES AND STANDARDS FOR WATER HEATING SYSTEMS, page 32
http://www.solar-rating.org/standard...OG300SEP02.pdf
Total Energy Draw 43.302 MJ (41,045 Btu)

Consumers Directory of Home Water Heater Ratings, page
http://www.gamanet.org/gama/inforesources.nsf/vAttachmentLaunch/BA8B7EB0CFA8AFEF85256E9000609F9A/$FILE/12-07-oil-rwh.pdf
Using the formula: 41045 Btu/EF($/Btu)*365

Calculating water heater costs for meaningful comparisons
http://www.daviddarling.info/encyclo...ater_cost.html
You need to know the unit cost of fuel
365 × 41045/EF × fuel cost (BTU) = estimated annual cost of operation
365 × 0.4105/EF × fuel cost (therm) = estimated annual cost of operation

Review of hot water heaters
http://www.consumersearch.com/www/ho...rs/review.html
365 X 41045/EF X Fuel Cost (BTU) = estimated annual cost of operation
365 X 0.4105/EF X Fuel Cost (therm) = estimated annual cost of operation

On-demand water heaters, page 8
http://www.naffainc.com/PDF-Files/on...r%20heater.pdf
..41045 x cost per therm of gas x 365 / EF = yearly cost to operate

etc.

I would guess any engineer should be able to tell us what this 41,045 magic
number really is.

On Sat, 16 Feb 2008 22:57:32 GMT, Donna Ohl, Grady Volunteer Coordinator
wrote:
I would guess any engineer should be able to tell us what this 41,045 magic
number really is.

I'm surprised a chemist or engineer isn't on this group.

I think this is the fundamental answer!

page 11, Water Heating Calculations
http://www.green-trust.org/2000/solar/solar.pdf
43,302 kJ/day is 41,045 Btu/day is the energy delivered to the hot water
load per day

And, this one says most plumbers don't understand the efficiency factor for
home water heaters

Residential Gas Water Heating:
Program Design & Specification Considerations, page 6
http://www.cee1.org/cee/mtg/09-07ppt...%20heating.ppt
Annual Savings (Therms/year) is based on the DOE Test Procedu
(41,045 Btu/EF*365)/100,000

On Feb 16, 5:57�pm, "Donna Ohl, Grady Volunteer Coordinator"
wrote:
On Wed, 13 Feb 2008 11:53:00 -0800 (PST), wrote:
On Wed, 13 Feb 2008 11:53:00 -0800 (PST), wrote:
But it still doesn't say where the "magic" 41,045 BTU comes from.

Whatever magic it is, googling for 41045 BTU gets *lots* of related PDFs!

Residential ACM Manual: Water Heating Calculation Method, page 8http://www..energy.ca.gov/title24/2005standards/residential_acm/2005_R...
The standard energy in the hot water delivered, 41,045 Btu/day.

Comments on Energy Star Ratings of Home Water Heaters, Page 5http://www.energystar.gov/ia/partners/prod_development/new_specs/down...
Using the formula: 41,045 Btu/EF($/Btu)*365

ENERGY STAR Residential Water Heaters: Analysis, page 10http://www.energystar.gov/ia/partners/prod_development/new_specs/down...
Energy consumption estimated using the DOE test procedure.
Based on the following formula: (41,045 BTU/EF x 365)/100,000

LIFE CYCLE COSTS AND SAVINGS FOR WATER HEATING SYSTEMS, page 3http://www1.eere.energy.gov/solar/ush2o/pdfs/life_cycle_costs_info_sh...
The annual delivered energy is 14.98 MMBtu (41045 Btu/day).

OPERATING GUIDELINES AND STANDARDS FOR WATER HEATING SYSTEMS, page 32http://www.solar-rating.org/standards/ogdocuments/OG300SEP02.pdf
Total Energy Draw 43.302 MJ (41,045 Btu)

Consumers Directory of Home Water Heater Ratings, pagehttp://www.gamanet.org/gama/inforesources.nsf/vAttachmentLaunch/BA8B7...
Using the formula: 41045 Btu/EF($/Btu)*365

Calculating water heater costs for meaningful comparisonshttp://www.daviddarling.info/encyclopedia/W/AE_water_heater_cost.html
You need to know the unit cost of fuel
365 � 41045/EF � fuel cost (BTU) = estimated annual cost of operation
365 � 0.4105/EF � fuel cost (therm) = estimated annual cost of operation

Review of hot water heatershttp://www.consumersearch.com/www/house_and_home/water-heaters/review...
365 X 41045/EF X Fuel Cost (BTU) = estimated annual cost of operation
365 X 0.4105/EF X Fuel Cost (therm) = estimated annual cost of operation

On-demand water heaters, page 8http://www.naffainc.com/PDF-Files/on%20demand%20water%20heater.pdf
.41045 x cost per therm of gas x 365 / EF = yearly cost to operate

etc.

I would guess any engineer should be able to tell us what this 41,045 magic
number really is.

maybe its a test standard somehow.

i have seen tanks under 30,000 BTU

On Sat 16 Feb 2008 23:08:42, Donna Ohl, Grady Volunteer Coordinator
wrote:

On Sat, 16 Feb 2008 22:57:32 GMT, Donna Ohl, Grady Volunteer
Coordinator wrote:
I would guess any engineer should be able to tell us what this
41,045 magic number really is.

I'm surprised a chemist or engineer isn't on this group.

I think this is the fundamental answer!

page 11, Water Heating Calculations
http://www.green-trust.org/2000/solar/solar.pdf
43,302 kJ/day is 41,045 Btu/day is the energy delivered to the hot
water load per day

And, this one says most plumbers don't understand the efficiency
factor for home water heaters

Residential Gas Water Heating:
Program Design & Specification Considerations, page 6
http://www.cee1.org/cee/mtg/09-07ppt...20Residential%
20%20Gas%20water%20heating.ppt
Annual Savings (Therms/year) is based on
the DOE Test Procedu (41,045 Btu/EF*365)/100,000


Boing!! Payoff.

You tell 'em Donna. Show them you knew the answer all along.

Poor " and others like him now don't know what's
hit them.

Nothing like reeling in a very long fishing line that you've
carefully laid out. Good one!!