I just started thinking about getting an electric water heater timer for my
3 year old 30 gallon water heater. I checked some of the reviews for the
Intermatic timers and it looks like everybody loves them and they say they
practically get their $40 bucks back each month.

Are timers all they seem to be cracked up to be and will turning off the
water heater from 10 PM to 8 AM really save a family of 4 a big chunk of
change each month?

On Aug 6, 9:31�pm, "Jordan" wrote:
I just started thinking about getting an electric water heater timer for my
3 year old 30 gallon water heater. �I checked some of the reviews for the
Intermatic timers and it looks like everybody loves them and they say they
practically get their $40 bucks back each month.

Are timers all they seem to be cracked up to be and will turning off the
water heater from 10 PM to 8 AM really save a family of 4 a big chunk of
change each month?

depends on your lifestyle, i would first add a water heater insulation
blanket and remember if you live where it gets cold the standby losses
help heat your home.

"Jordan" wrote in message
. ..
I just started thinking about getting an electric water heater timer for my
3 year old 30 gallon water heater. I checked some of the reviews for the
Intermatic timers and it looks like everybody loves them and they say they
practically get their $40 bucks back each month.

Are timers all they seem to be cracked up to be and will turning off the
water heater from 10 PM to 8 AM really save a family of 4 a big chunk of
change each month?

You use water heater timers with large tank water heaters, where the utility
company has electric meters with timers in them, and charge a lower amount
during off peak times, which is usually in the middle of the night.
Personally, I doubt there is much savings at all, unless you wind up taking
lots of cold showers

On Wed, 06 Aug 2008 20:09:53 -0700, Smitty Two
wrote:


There is one caveat. If your water heater is so poorly insulated or so
unfavorably situated that the water temp inside returns to supply
ambient before those ten hours elapse, then you'll save. Since you're
obviously energy conscious, that caveat likely doesn't apply.

I've turned off the electricity to my water heater and it stays pretty
hot for 3 days iirc. And it would stay hot a lot longer if I weren't
using the hot water. The major thing cooling off the water is the
cold water going in when I use hot water.


Usage is very strange. I went away for November and December (and my
billing periods were from the 15th to the 14th, and my bill was almost
the same as the previous year when I was here the whole time.

The water heater was off, and empty. The furnaace was down to about 45
and it's oil so it only used electricity to run the ignition and
blower, and the furance fan.

About 4 lights were on timers, but I leave 3 of them on timers even
when I'm home.

It was not an estimated reading.

I still haven't figured it out.

On Aug 6, 11:09*pm, Smitty Two wrote:
In article ,

*"Jordan" wrote:
I just started thinking about getting an electric water heater timer for my
3 year old 30 gallon water heater. *I checked some of the reviews for the
Intermatic timers and it looks like everybody loves them and they say they
practically get their $40 bucks back each month.

Are timers all they seem to be cracked up to be and will turning off the
water heater from 10 PM to 8 AM really save a family of 4 a big chunk of
change each month?

I don't think it'll save you a plug nickel. The amount of heat lost
during those 10 hours is exactly the amount of heat that has to be put
back in.

That's true, but the amount of heat lost when you have the water
heater turned off at night is less than the amount of heat that would
have been lost had it been maintained at normal temperature. The
rate of heat loss is directly proportional to the temp difference.
As the tank slowly cools, the rate of heat loss slows. The concept
here is exactly the same as turning down the thermostat over night on
a heating system. It definitely uses less energy, even though in the
morning it has to recover back to normal temp.



It doesn't matter one whit whether it's done all at once in the
morning, or incrementally throughout the night.

Yes it does, because of the above.




There is one caveat. If your water heater is so poorly insulated or so
unfavorably situated that the water temp inside returns to supply
ambient before those ten hours elapse, then you'll save. Since you're
obviously energy conscious, that caveat likely doesn't apply.


Totally false reasoning here.

In article ,
mm wrote:

On Wed, 06 Aug 2008 20:09:53 -0700, Smitty Two
wrote:


There is one caveat. If your water heater is so poorly insulated or so
unfavorably situated that the water temp inside returns to supply
ambient before those ten hours elapse, then you'll save. Since you're
obviously energy conscious, that caveat likely doesn't apply.

I've turned off the electricity to my water heater and it stays pretty
hot for 3 days iirc. And it would stay hot a lot longer if I weren't
using the hot water. The major thing cooling off the water is the
cold water going in when I use hot water.


Usage is very strange. I went away for November and December (and my
billing periods were from the 15th to the 14th, and my bill was almost
the same as the previous year when I was here the whole time.

The water heater was off, and empty. The furnaace was down to about 45
and it's oil so it only used electricity to run the ignition and
blower, and the furance fan.

About 4 lights were on timers, but I leave 3 of them on timers even
when I'm home.

It was not an estimated reading.

I still haven't figured it out.

We love a good mystery. I'm sure you know that for comparison, it's
kilowatt-hours that count, not dollars. How old is that refrigerator?

"Smitty Two" wrote in message
news

I don't think it'll save you a plug nickel. The amount of heat lost
during those 10 hours is exactly the amount of heat that has to be put
back in. It doesn't matter one whit whether it's done all at once in the
morning, or incrementally throughout the night.

There is one caveat. If your water heater is so poorly insulated or so
unfavorably situated that the water temp inside returns to supply
ambient before those ten hours elapse, then you'll save. Since you're
obviously energy conscious, that caveat likely doesn't apply.

What about me?
My WH is on for one hour daily (manually, when I get up in the AM). I take
my shower and wash dishes, then shut it off . There's still enough residual
hot water during the day for hand washing, etc. My clothes washer is only
used with cold water.

On Aug 6, 8:31*pm, "Jordan" wrote:
I just started thinking about getting an electric water heater timer for my
3 year old 30 gallon water heater. *I checked some of the reviews for the
Intermatic timers and it looks like everybody loves them and they say they
practically get their $40 bucks back each month.

Are timers all they seem to be cracked up to be and will turning off the
water heater from 10 PM to 8 AM really save a family of 4 a big chunk of
change each month?

Nobody is getting 40 back, My total bill for the electric tank was
under 40 a month, I know because that is how much it went down when I
switched to Ng. Do a test, my tank still had warm water in it after 5
days when I would leave and turn off the power. See how much it drops
overnight, you will be just reheating it and may save nothing.
Insulate pipes and the tank, that will save money, turn down the temp
so you only need hot water for a shower, that will save alot.

In article ,
"PanHandler" wrote:

"Smitty Two" wrote in message
news

I don't think it'll save you a plug nickel. The amount of heat lost
during those 10 hours is exactly the amount of heat that has to be put
back in. It doesn't matter one whit whether it's done all at once in the
morning, or incrementally throughout the night.

There is one caveat. If your water heater is so poorly insulated or so
unfavorably situated that the water temp inside returns to supply
ambient before those ten hours elapse, then you'll save. Since you're
obviously energy conscious, that caveat likely doesn't apply.

What about me?
My WH is on for one hour daily (manually, when I get up in the AM). I take
my shower and wash dishes, then shut it off . There's still enough residual
hot water during the day for hand washing, etc. My clothes washer is only
used with cold water.

I doubt you're saving anything. If you used hot water one day per week,
then it might save you to shut it off for the other six days. For all
intents and purposes*, you don't save until it's been off long enough to
cool down to whatever temp your cold water supply is.

*Someone will no doubt offer that the greater the temperature difference
between water in the tank and the surrounding air, the faster heat will
be lost. So it's theoretically possible that my original statement ("It
doesn't matter one whit whether it's done all at once in the morning, or
incrementally throughout the night.") isn't *exactly* true, it's
probably within a few pennies of being true.

On Aug 6, 8:31*pm, "Jordan" wrote:
I just started thinking about getting an electric water heater timer for my
3 year old 30 gallon water heater. *I checked some of the reviews for the
Intermatic timers and it looks like everybody loves them and they say they
practically get their $40 bucks back each month.

Are timers all they seem to be cracked up to be and will turning off the
water heater from 10 PM to 8 AM really save a family of 4 a big chunk of
change each month?

What kind of timer, what does it consume 24x7, thats an extra charge.
I have some commercial timers that consume maybe 4-5$ a month
themselves. You might save 2-4$ on the tank and pay 5$ to run the
timer.

"Smitty Two" wrote in message
news
In article ,
"PanHandler" wrote:

What about me?
My WH is on for one hour daily (manually, when I get up in the AM). I
take
my shower and wash dishes, then shut it off . There's still enough
residual
hot water during the day for hand washing, etc. My clothes washer is only
used with cold water.

I doubt you're saving anything. If you used hot water one day per week,
then it might save you to shut it off for the other six days. For all
intents and purposes*, you don't save until it's been off long enough to
cool down to whatever temp your cold water supply is.

Compared to being on all the time, how could it not save me substantially if
it only runs thirty hours a month? It seems to defy logic.

On Aug 7, 9:49*am, Smitty Two wrote:
In article ,





*"PanHandler" wrote:
"Smitty Two" wrote in message
news

I don't think it'll save you a plug nickel. The amount of heat lost
during those 10 hours is exactly the amount of heat that has to be put
back in. It doesn't matter one whit whether it's done all at once in the
morning, or incrementally throughout the night.

There is one caveat. If your water heater is so poorly insulated or so
unfavorably situated that the water temp inside returns to supply
ambient before those ten hours elapse, then you'll save. Since you're
obviously energy conscious, that caveat likely doesn't apply.

What about me?
My WH is on for one hour daily (manually, when I get up in the AM). I take
my shower and wash dishes, then shut it off . There's still enough residual
hot water during the day for hand washing, etc. My clothes washer is only
used with cold water.

I doubt you're saving anything. If you used hot water one day per week,
then it might save you to shut it off for the other six days. For all
intents and purposes*, you don't save until it's been off long enough to
cool down to whatever temp your cold water supply is.

*Someone will no doubt offer that the greater the temperature difference
between water in the tank and the surrounding air, the faster heat will
be lost. So it's theoretically possible that my original statement ("It
doesn't matter one whit whether it's done all at once in the morning, or
incrementally throughout the night.") isn't *exactly* true, it's
probably within a few pennies of being true.- Hide quoted text -

- Show quoted text -

It's not "theoretical" that your original statement is incorrect.
From elementary physics, which you yourself cite above, it's clear
that a water heater turned off all night will use less energy than one
left at normal temp. Now, whether the savings are enough to make it
worthwhile to install a timer, is an entirely different question.

Here's what the DOE has to say:

http://www.eere.energy.gov/consumer/.../mytopic=13110

"Install a Timer and Use Off-Peak Power for Electric Water Heaters

If you have an electric water heater, you can save an additional 5%–
12% of energy by installing a timer that turns it off at night when
you don't use hot water and/or during your utility's peak demand
times."


So, if you have a bill of $20 a month, that's $12 at the low end.
Maybe not enough for some to consider, but clearly more than a plug
nickel.

On Aug 7, 10:49*am, wrote:
On Aug 7, 9:49*am, Smitty Two wrote:





In article ,

*"PanHandler" wrote:
"Smitty Two" wrote in message
news

I don't think it'll save you a plug nickel. The amount of heat lost
during those 10 hours is exactly the amount of heat that has to be put
back in. It doesn't matter one whit whether it's done all at once in the
morning, or incrementally throughout the night.

There is one caveat. If your water heater is so poorly insulated or so
unfavorably situated that the water temp inside returns to supply
ambient before those ten hours elapse, then you'll save. Since you're
obviously energy conscious, that caveat likely doesn't apply.

What about me?
My WH is on for one hour daily (manually, when I get up in the AM). I take
my shower and wash dishes, then shut it off . There's still enough residual
hot water during the day for hand washing, etc. My clothes washer is only
used with cold water.

I doubt you're saving anything. If you used hot water one day per week,
then it might save you to shut it off for the other six days. For all
intents and purposes*, you don't save until it's been off long enough to
cool down to whatever temp your cold water supply is.

*Someone will no doubt offer that the greater the temperature difference
between water in the tank and the surrounding air, the faster heat will
be lost. So it's theoretically possible that my original statement ("It
doesn't matter one whit whether it's done all at once in the morning, or
incrementally throughout the night.") isn't *exactly* true, it's
probably within a few pennies of being true.- Hide quoted text -

- Show quoted text -

It's not "theoretical" that your original statement is incorrect.
From elementary physics, which you yourself cite above, it's clear
that a water heater turned off all night will use less energy than one
left at normal temp. * Now, whether the savings are enough to make it
worthwhile to install a timer, is an entirely different question.

Here's what the DOE has to say:

http://www.eere.energy.gov/consumer/...ting/index.cfm...

"Install a Timer and Use Off-Peak Power for Electric Water Heaters

If you have an electric water heater, you can save an additional 5%–
12% of energy by installing a timer that turns it off at night when
you don't use hot water and/or during your utility's peak demand
times."

So, if you have a bill of $20 a month, that's $12 at the low end.
Maybe not enough for some to consider, but clearly more than a plug
nickel.- Hide quoted text -

- Show quoted text -

perhaps the OP could put a watt hour meter on the tank, and record how
much power used for a couple months? then add timer and compare?

of course less convenient is manually turning tank off on for a month
and see if your power bill changes.

but i doubt the savings will be much, add a water heater insulation
blanket

On Aug 7, 10:03*am, " wrote:
On Aug 7, 10:49*am, wrote:





On Aug 7, 9:49*am, Smitty Two wrote:

In article ,

*"PanHandler" wrote:
"Smitty Two" wrote in message
news

I don't think it'll save you a plug nickel. The amount of heat lost
during those 10 hours is exactly the amount of heat that has to be put
back in. It doesn't matter one whit whether it's done all at once in the
morning, or incrementally throughout the night.

There is one caveat. If your water heater is so poorly insulated or so
unfavorably situated that the water temp inside returns to supply
ambient before those ten hours elapse, then you'll save. Since you're
obviously energy conscious, that caveat likely doesn't apply.

What about me?
My WH is on for one hour daily (manually, when I get up in the AM). I take
my shower and wash dishes, then shut it off . There's still enough residual
hot water during the day for hand washing, etc. My clothes washer is only
used with cold water.

I doubt you're saving anything. If you used hot water one day per week,
then it might save you to shut it off for the other six days. For all
intents and purposes*, you don't save until it's been off long enough to
cool down to whatever temp your cold water supply is.

*Someone will no doubt offer that the greater the temperature difference
between water in the tank and the surrounding air, the faster heat will
be lost. So it's theoretically possible that my original statement ("It
doesn't matter one whit whether it's done all at once in the morning, or
incrementally throughout the night.") isn't *exactly* true, it's
probably within a few pennies of being true.- Hide quoted text -

- Show quoted text -

It's not "theoretical" that your original statement is incorrect.
From elementary physics, which you yourself cite above, it's clear
that a water heater turned off all night will use less energy than one
left at normal temp. * Now, whether the savings are enough to make it
worthwhile to install a timer, is an entirely different question.

Here's what the DOE has to say:

http://www.eere.energy.gov/consumer/...ting/index.cfm...

"Install a Timer and Use Off-Peak Power for Electric Water Heaters

If you have an electric water heater, you can save an additional 5%–
12% of energy by installing a timer that turns it off at night when
you don't use hot water and/or during your utility's peak demand
times."

So, if you have a bill of $20 a month, that's $12 at the low end.
Maybe not enough for some to consider, but clearly more than a plug
nickel.- Hide quoted text -

- Show quoted text -

perhaps the OP could put a watt hour meter on the tank, and record how
much power used for a couple months? then add timer and compare?

of course less convenient is manually turning tank off on for a month
and see if your power bill changes.

but i doubt the savings will be much, add a water heater insulation
blanket- Hide quoted text -

- Show quoted text -

A problem in my area is ground and basement temp changes all year, so
does incomming water temp, as the 90s fade the ground cools off and
electric consumption increases, to monitor exact savings is hard. And
what does his timer cost to run.

On Thu, 07 Aug 2008 05:36:26 -0700, Smitty Two
wrote:

In article ,
mm wrote:

On Wed, 06 Aug 2008 20:09:53 -0700, Smitty Two
wrote:


There is one caveat. If your water heater is so poorly insulated or so
unfavorably situated that the water temp inside returns to supply
ambient before those ten hours elapse, then you'll save. Since you're
obviously energy conscious, that caveat likely doesn't apply.

I've turned off the electricity to my water heater and it stays pretty
hot for 3 days iirc. And it would stay hot a lot longer if I weren't
using the hot water. The major thing cooling off the water is the
cold water going in when I use hot water.


Usage is very strange. I went away for November and December (and my
billing periods were from the 15th to the 14th, and my bill was almost
the same as the previous year when I was here the whole time.

The water heater was off, and empty. The furnaace was down to about 45
and it's oil so it only used electricity to run the ignition and
blower, and the furance fan.

About 4 lights were on timers, but I leave 3 of them on timers even
when I'm home.

It was not an estimated reading.

I still haven't figured it out.

We love a good mystery. I'm sure you know that for comparison, it's
kilowatt-hours that count, not dollars. How old is that refrigerator?

Yeah, I forgot to say that I compared KwH, not dollars.

The fridge is only 29 years old, but when I was away, I didn't open
the door at all, so however high the electric usage it was, it should
have been less, a lot less, when I was away.

If I'm lucky I may go away for 2 months March and April of next
year**. I'll try to do a better job, if possible, of comparing then

**Prior to last years trip I hadn't been anywhere except to visit my
brother in 10 years. Plus I'm trying to sell a project on these trips
(but haven't attempted to deduct even a fraction of the costs. I don't
think I can since I've not gotten any revenue.)

In article
,
wrote:

On Aug 7, 9:49*am, Smitty Two wrote:
In article ,





*"PanHandler" wrote:
"Smitty Two" wrote in message
news

I don't think it'll save you a plug nickel. The amount of heat lost
during those 10 hours is exactly the amount of heat that has to be put
back in. It doesn't matter one whit whether it's done all at once in
the
morning, or incrementally throughout the night.

There is one caveat. If your water heater is so poorly insulated or so
unfavorably situated that the water temp inside returns to supply
ambient before those ten hours elapse, then you'll save. Since you're
obviously energy conscious, that caveat likely doesn't apply.

What about me?
My WH is on for one hour daily (manually, when I get up in the AM). I
take
my shower and wash dishes, then shut it off . There's still enough
residual
hot water during the day for hand washing, etc. My clothes washer is only
used with cold water.

I doubt you're saving anything. If you used hot water one day per week,
then it might save you to shut it off for the other six days. For all
intents and purposes*, you don't save until it's been off long enough to
cool down to whatever temp your cold water supply is.

*Someone will no doubt offer that the greater the temperature difference
between water in the tank and the surrounding air, the faster heat will
be lost. So it's theoretically possible that my original statement ("It
doesn't matter one whit whether it's done all at once in the morning, or
incrementally throughout the night.") isn't *exactly* true, it's
probably within a few pennies of being true.- Hide quoted text -

- Show quoted text -

It's not "theoretical" that your original statement is incorrect.
From elementary physics, which you yourself cite above, it's clear
that a water heater turned off all night will use less energy than one
left at normal temp.

I meant to keep the logic and explanation simple. I still say we're
talking pennies.

Now, whether the savings are enough to make it
worthwhile to install a timer, is an entirely different question.

Here's what the DOE has to say:

http://www.eere.energy.gov/consumer/your home/water
heating/index.cfm/mytopic=13110

"Install a Timer and Use Off-Peak Power for Electric Water Heaters

If you have an electric water heater, you can save an additional 5%*
12% of energy by installing a timer that turns it off at night when
you don't use hot water and/or during your utility's peak demand
times."


So, if you have a bill of $20 a month, that's $12 at the low end.
Maybe not enough for some to consider, but clearly more than a plug
nickel.

Sorry, peak hours are *not* at night. I'd venture that 99% of the DOE's
supposed savings is due to a reduction in the price per kwh. Not only
that, they aren't talking about your *total* electric bill, only the
portion of it that the WH accounts for. So the logic behind your $8
savings is flawed.

This problem is a minor modification of the jacuzzi heating question,
and the same logic applies. Every speck of heat lost through the night
has to be replaced. Do it in small chunks, or do it all at once. Same
amount of energy is expended, disregarding the *very* minor difference
noted (that rate of heat loss decreases as temp. differential decreases.)

"Smitty Two" wrote in message
news
Sorry, peak hours are *not* at night. I'd venture that 99% of the DOE's
supposed savings is due to a reduction in the price per kwh. Not only
that, they aren't talking about your *total* electric bill, only the
portion of it that the WH accounts for. So the logic behind your $8
savings is flawed.

This problem is a minor modification of the jacuzzi heating question,
and the same logic applies. Every speck of heat lost through the night
has to be replaced. Do it in small chunks, or do it all at once. Same
amount of energy is expended, disregarding the *very* minor difference
noted (that rate of heat loss decreases as temp. differential decreases.)

Please reply to my earlier post:
Compared to being on all the time, how could it not save me substantially if
it only runs thirty hours a month? It seems to defy logic.
Thank you.

On Aug 7, 11:52*am, "PanHandler" wrote:
"Smitty Two" wrote in message

news
Sorry, peak hours are *not* at night. I'd venture that 99% of the DOE's
supposed savings is due to a reduction in the price per kwh. Not only
that, they aren't talking about your *total* electric bill, only the
portion of it that the WH accounts for. So the logic behind your $8
savings is flawed.

This problem is a minor modification of the jacuzzi heating question,
and the same logic applies. Every speck of heat lost through the night
has to be replaced. Do it in small chunks, or do it all at once. Same
amount of energy is expended, disregarding the *very* minor difference
noted (that rate of heat loss decreases as temp. differential decreases..)

Please reply to my earlier post:
Compared to being on all the time, how could it not save me substantially if
it only runs thirty hours a month? It seems to defy logic.
Thank you.

It will save as the water temp drops less heat is lost because the
differential of water to room temp is less. But if the cycle is to
short you are just reheating the water to use again. My electric was
still warm after 5 days. Electric tank if well insulated hold in heat.
What is saved depends on alot of things, what does the timer consume,
Insulation value of tank, basement temp. I think since your cycle is
short it may not save much. A 40$ savings is bs, my electric tank
costed about 45 a month. maybe you will save 5-15%, a guess. try
turning it off at the switch and see.

"ransley" wrote in message
...

Please reply to my earlier post:
Compared to being on all the time, how could it not save me substantially
if
it only runs thirty hours a month? It seems to defy logic.
Thank you.

It will save as the water temp drops less heat is lost because the
differential of water to room temp is less. But if the cycle is to
short you are just reheating the water to use again. My electric was
still warm after 5 days. Electric tank if well insulated hold in heat.
What is saved depends on alot of things, what does the timer consume,
Insulation value of tank, basement temp. I think since your cycle is
short it may not save much. A 40$ savings is bs, my electric tank
costed about 45 a month. maybe you will save 5-15%, a guess. try
turning it off at the switch and see.

This is my original post:
What about me?
My WH is on for one hour daily (manually, when I get up in the AM). I take
my shower and wash dishes, then shut it off. There's still enough residual
hot water during the day for hand washing, etc. My clothes washer is only
used with cold water.

Reread the above and try again. No timer. It's off until the next morning.
Simple question - Compared to being on all the time, how could it NOT save
me substantially if
it only runs thirty hours a month compared to cycling for thirty days?

On Aug 7, 12:49*pm, "PanHandler" wrote:
"ransley" wrote in message

...

Please reply to my earlier post:
Compared to being on all the time, how could it not save me substantially
if
it only runs thirty hours a month? It seems to defy logic.
Thank you.

It will save as the water temp drops less heat is lost because the
differential of water to room temp is less. But if the cycle is to
short you are just reheating the water to use again. My electric was
still warm after 5 days. Electric tank if well insulated hold in heat.
What is saved depends on alot of things, what does the timer consume,
Insulation value of tank, basement temp. I think since your cycle is
short it may not save much. A 40$ savings is bs, my electric tank
costed about 45 a month. maybe you will save 5-15%, a guess. try
turning it off at the switch and see.

This is my original post:
What about me?
My WH is on for one hour daily (manually, when I get up in the AM). I take
my shower and wash dishes, then shut it off. There's still enough residual
hot water during the day for hand washing, etc. My clothes washer is only
used with cold water.

Reread the above and try again. No timer. It's off until the next morning..
Simple question - Compared to being on all the time, how could it NOT save
me substantially if
it only runs thirty hours a month compared to cycling for thirty days?

Yes it will save you money but I have no idea how much. The answer
would be how much it would have run to cycle. An old water heater will
save more since new ones have much better foam insulation

On Thu, 07 Aug 2008 09:46:19 -0700, Smitty Two
wrote:

SNIP

This problem is a minor modification of the jacuzzi heating question,
and the same logic applies. Every speck of heat lost through the night
has to be replaced. Do it in small chunks, or do it all at once. Same
amount of energy is expended, disregarding the *very* minor difference
noted (that rate of heat loss decreases as temp. differential decreases.)

I believe you are on the right track. I have nothing to back up my
theory but here goes. It seems to me you only save after the tank
water temp has cooled to incoming water temp. Then the time off would
be the same as never having turned it on. This, assuming you have done
the other things such as insulation and stopping leaks.

--Andy Asberry--
------Texas-----

"PanHandler" wrote in message
...

This is my original post:
What about me?
My WH is on for one hour daily (manually, when I get up in the AM). I take
my shower and wash dishes, then shut it off. There's still enough residual
hot water during the day for hand washing, etc. My clothes washer is only
used with cold water.

Reread the above and try again. No timer. It's off until the next morning.
Simple question - Compared to being on all the time, how could it NOT save me
substantially if
it only runs thirty hours a month compared to cycling for thirty days?

The biggest saving will be because you turn it off after you shower, before it
reheats. So heat loss will be less for the whole day. Turn it off BEFORE you
shower, and you will save even more, assuming the water is hot enough to finish
your shower.

"Andy Asberry" wrote in message
...
On Thu, 07 Aug 2008 09:46:19 -0700, Smitty Two
wrote:

SNIP

This problem is a minor modification of the jacuzzi heating question,
and the same logic applies. Every speck of heat lost through the night
has to be replaced. Do it in small chunks, or do it all at once. Same
amount of energy is expended, disregarding the *very* minor difference
noted (that rate of heat loss decreases as temp. differential decreases.)

I believe you are on the right track. I have nothing to back up my
theory but here goes. It seems to me you only save after the tank
water temp has cooled to incoming water temp. Then the time off would
be the same as never having turned it on. This, assuming you have done
the other things such as insulation and stopping leaks.

How many times in this thread have you made the same, obviously erronious claim?
You save any time the water in the tank remians cooler than normal. In many
places, the water would NEVER even reach the incoming water temp, which is lower
than room temp.

In article ,
"PanHandler" wrote:

"Smitty Two" wrote in message
news
Sorry, peak hours are *not* at night. I'd venture that 99% of the DOE's
supposed savings is due to a reduction in the price per kwh. Not only
that, they aren't talking about your *total* electric bill, only the
portion of it that the WH accounts for. So the logic behind your $8
savings is flawed.

This problem is a minor modification of the jacuzzi heating question,
and the same logic applies. Every speck of heat lost through the night
has to be replaced. Do it in small chunks, or do it all at once. Same
amount of energy is expended, disregarding the *very* minor difference
noted (that rate of heat loss decreases as temp. differential decreases.)

Please reply to my earlier post:
Compared to being on all the time, how could it not save me substantially if
it only runs thirty hours a month? It seems to defy logic.
Thank you.

Perhaps the confusion stems from some ambiguity in the word *on.* An
electric water heater is not *on* all the time anymore than a
refrigerator is *on* all the time, or a motion sensor light.

The refrigerator is triggered to come on when the temperature rises
above a certain threshold. The motion sensor light is triggered to turn
on when motion is detected.

And the water heater is triggered to come on when the water temp falls
below a certain threshold. The fact that it hasn't been "turned off"
doesn't mean that it's consuming electricity.

Let's say that between a shower and other needs, and heat leaking to the
surroundings, your tank loses 50 degrees in 24 hours. And let's say it
can make up that 50 degree loss in an hour.

It will use just as much electricity if it comes on for one hour every
day, making up the whole 50 degrees at once, or if it comes on for six
minutes, 10 times per day, increasing the water temp in the tank 5
degrees each time.

In article ,
"Bob F" wrote:

"Andy Asberry" wrote in message
...
On Thu, 07 Aug 2008 09:46:19 -0700, Smitty Two
wrote:

SNIP

This problem is a minor modification of the jacuzzi heating question,
and the same logic applies. Every speck of heat lost through the night
has to be replaced. Do it in small chunks, or do it all at once. Same
amount of energy is expended, disregarding the *very* minor difference
noted (that rate of heat loss decreases as temp. differential decreases.)

I believe you are on the right track. I have nothing to back up my
theory but here goes. It seems to me you only save after the tank
water temp has cooled to incoming water temp. Then the time off would
be the same as never having turned it on. This, assuming you have done
the other things such as insulation and stopping leaks.

How many times in this thread have you made the same, obviously erronious
claim?
You save any time the water in the tank remians cooler than normal. In many
places, the water would NEVER even reach the incoming water temp, which is
lower
than room temp.

You responded to Andy. Are you addressing me?

On Aug 7, 11:50�pm, Smitty Two wrote:
In article ,





�"PanHandler" wrote:
"Smitty Two" wrote in message
news

Sorry, peak hours are *not* at night. I'd venture that 99% of the DOE's
supposed savings is due to a reduction in the price per kwh. Not only
that, they aren't talking about your *total* electric bill, only the
portion of it that the WH accounts for. So the logic behind your $8
savings is flawed.

This problem is a minor modification of the jacuzzi heating question,
and the same logic applies. Every speck of heat lost through the night
has to be replaced. Do it in small chunks, or do it all at once. Same
amount of energy is expended, disregarding the *very* minor difference
noted (that rate of heat loss decreases as temp. differential decreases.)

Please reply to my earlier post:
Compared to being on all the time, how could it not save me substantially if
it only runs thirty hours a month? It seems to defy logic.
Thank you.

Perhaps the confusion stems from some ambiguity in the word *on.* An
electric water heater is not *on* all the time anymore than a
refrigerator is *on* all the time, or a motion sensor light.

The refrigerator is triggered to come on when the temperature rises
above a certain threshold. The motion sensor light is triggered to turn
on when motion is detected.

And the water heater is triggered to come on when the water temp falls
below a certain threshold. The fact that it hasn't been "turned off"
doesn't mean that it's consuming electricity.

Let's say that between a shower and other needs, and heat leaking to the
surroundings, your tank loses 50 degrees in 24 hours. And let's say it
can make up that 50 degree loss in an hour.

It will use just as much electricity if it comes on for one hour every
day, making up the whole 50 degrees at once, or if it comes on for six
minutes, 10 times per day, increasing the water temp in the tank 5
degrees each time.- Hide quoted text -

- Show quoted text -

technically a cooler tank loses less energy, but for practical
purposes the timer will likely not pay for itself. better to add
insulation to the tanks and lines

On Aug 7, 11:50*pm, Smitty Two wrote:
In article ,





*"PanHandler" wrote:
"Smitty Two" wrote in message
news

Sorry, peak hours are *not* at night. I'd venture that 99% of the DOE's
supposed savings is due to a reduction in the price per kwh. Not only
that, they aren't talking about your *total* electric bill, only the
portion of it that the WH accounts for. So the logic behind your $8
savings is flawed.

This problem is a minor modification of the jacuzzi heating question,
and the same logic applies. Every speck of heat lost through the night
has to be replaced. Do it in small chunks, or do it all at once. Same
amount of energy is expended, disregarding the *very* minor difference
noted (that rate of heat loss decreases as temp. differential decreases.)

Please reply to my earlier post:
Compared to being on all the time, how could it not save me substantially if
it only runs thirty hours a month? It seems to defy logic.
Thank you.

Perhaps the confusion stems from some ambiguity in the word *on.* An
electric water heater is not *on* all the time anymore than a
refrigerator is *on* all the time, or a motion sensor light.

The refrigerator is triggered to come on when the temperature rises
above a certain threshold. The motion sensor light is triggered to turn
on when motion is detected.

And the water heater is triggered to come on when the water temp falls
below a certain threshold. The fact that it hasn't been "turned off"
doesn't mean that it's consuming electricity.

Let's say that between a shower and other needs, and heat leaking to the
surroundings, your tank loses 50 degrees in 24 hours. And let's say it
can make up that 50 degree loss in an hour.

It will use just as much electricity if it comes on for one hour every
day, making up the whole 50 degrees at once, or if it comes on for six
minutes, 10 times per day, increasing the water temp in the tank 5
degrees each time.- Hide quoted text -

- Show quoted text -


Despite your post acknowledging that this was not true, where you
seemed to recognize your earlier posts were incorrect, here we go
again. In your above example, yes the water heater uses the same
amount of energy because it runs for only 60 mins either way. The
big difference is that in the case of the frequent reheating, at the
end, you wind up with a tank of water that is at a slightly lower
temp. You seem to have a problem confusing what may be practical and/
or worth doing with pure physics. The amount of heat loss is
proportional to the temp difference. If the tank is reheated
frequently, or just left on to maintain the normal temp, the tank will
be losing MORE energy as heat loss. Therefore at the end of the
period, it either uses more electricity to get to the same temp, or
with the same amount of electricity ends up at a lower final temp.

If things worked as you claimed, why is setting back the temp of a
house overnight effective in lowering energy usage? It's the same
thing. The energy lost over night has to be made back up in the
morning when it recovers. Following your logic, there would be no
savings. But of course there is. The exact same thing holds true
with the water heater example, but the difference is smaller.

Now, you can argue whether the savings are enough to warrant doing
it. But you can't argue the physics, which you appear to be doing by
your mistatements.

On Aug 7, 11:52*pm, Smitty Two wrote:
In article ,
*"Bob F" wrote:





"Andy Asberry" wrote in message
.. .
On Thu, 07 Aug 2008 09:46:19 -0700, Smitty Two
wrote:

SNIP

This problem is a minor modification of the jacuzzi heating question,
and the same logic applies. Every speck of heat lost through the night
has to be replaced. Do it in small chunks, or do it all at once. Same
amount of energy is expended, disregarding the *very* minor difference
noted (that rate of heat loss decreases as temp. differential decreases.)

I believe you are on the right track. I have nothing to back up my
theory but here goes. It seems to me you only save after the tank
water temp has cooled to incoming water temp. Then the time off would
be the same as never having turned it on. This, assuming you have done
the other things such as insulation and stopping leaks.

How many times in this thread have you made the same, obviously erronious
claim?
You save any time the water in the tank remians cooler than normal. In many
places, the water would NEVER even reach the incoming water temp, which is
lower
than room temp.

You responded to Andy. Are you addressing me?- Hide quoted text -

- Show quoted text -

I don;t know, but I'd say the comment could apply to either of you.
As Bob F states, you save energy anytime you allow the water in the
tank to cool down to a lower temp than it would be at if the heater
was left on. Again, I'm not debating whether the savings are
sufficient to make it practical. But you can't deny the physics
here.

From a physics standpoint, it's the exact same thing as setting back
the temp in a home overnight to save energy. And the DOE clearly says
it is worth doing, but without seeing actual numbers, we don't know
exactly how much anyone is actually going to save.

On Aug 7, 9:47*am, ransley wrote:
On Aug 6, 8:31*pm, "Jordan" wrote:

I just started thinking about getting an electric water heater timer for my
3 year old 30 gallon water heater. *I checked some of the reviews for the
Intermatic timers and it looks like everybody loves them and they say they
practically get their $40 bucks back each month.

Are timers all they seem to be cracked up to be and will turning off the
water heater from 10 PM to 8 AM really save a family of 4 a big chunk of
change each month?

Nobody is getting 40 back, My total bill for the electric tank was
under 40 a month, I know because that is how much it went down when I
switched to Ng. Do a test, my tank still had warm water in it after 5
days when I would leave and turn off the power. See how much it drops
overnight, you will be just reheating it and may save nothing.

Of course it has to be reheated, but once again, that DOES NOT
TRANSLATE INTO SAVING NOTHING. In fact, the more it has to be
reheated, the MORE he saves. You do have one good point here, and
that is to measure the water temp one night just before turning it
off, then measure again in the AM before turing it back on. The
smaller the temp drop, the less energy will be saved. That should
give a good indication of how practical it would be. Could it be so
small that it's not worth it? Sure. But that is different than
saying it doesn't actually save any energy at all.




Insulate pipes and the tank, that will save money, turn down the temp
so you only need hot water for a shower, that will save alot.

In article
,
wrote:

On Aug 7, 11:50*pm, Smitty Two wrote:
In article ,





*"PanHandler" wrote:
"Smitty Two" wrote in message
news

Sorry, peak hours are *not* at night. I'd venture that 99% of the DOE's
supposed savings is due to a reduction in the price per kwh. Not only
that, they aren't talking about your *total* electric bill, only the
portion of it that the WH accounts for. So the logic behind your $8
savings is flawed.

This problem is a minor modification of the jacuzzi heating question,
and the same logic applies. Every speck of heat lost through the night
has to be replaced. Do it in small chunks, or do it all at once. Same
amount of energy is expended, disregarding the *very* minor difference
noted (that rate of heat loss decreases as temp. differential
decreases.)

Please reply to my earlier post:
Compared to being on all the time, how could it not save me substantially
if
it only runs thirty hours a month? It seems to defy logic.
Thank you.

Perhaps the confusion stems from some ambiguity in the word *on.* An
electric water heater is not *on* all the time anymore than a
refrigerator is *on* all the time, or a motion sensor light.

The refrigerator is triggered to come on when the temperature rises
above a certain threshold. The motion sensor light is triggered to turn
on when motion is detected.

And the water heater is triggered to come on when the water temp falls
below a certain threshold. The fact that it hasn't been "turned off"
doesn't mean that it's consuming electricity.

Let's say that between a shower and other needs, and heat leaking to the
surroundings, your tank loses 50 degrees in 24 hours. And let's say it
can make up that 50 degree loss in an hour.

It will use just as much electricity if it comes on for one hour every
day, making up the whole 50 degrees at once, or if it comes on for six
minutes, 10 times per day, increasing the water temp in the tank 5
degrees each time.- Hide quoted text -

- Show quoted text -


Despite your post acknowledging that this was not true, where you
seemed to recognize your earlier posts were incorrect, here we go
again. In your above example, yes the water heater uses the same
amount of energy because it runs for only 60 mins either way. The
big difference is that in the case of the frequent reheating, at the
end, you wind up with a tank of water that is at a slightly lower
temp. You seem to have a problem confusing what may be practical and/
or worth doing with pure physics. The amount of heat loss is
proportional to the temp difference. If the tank is reheated
frequently, or just left on to maintain the normal temp, the tank will
be losing MORE energy as heat loss. Therefore at the end of the
period, it either uses more electricity to get to the same temp, or
with the same amount of electricity ends up at a lower final temp.

If things worked as you claimed, why is setting back the temp of a
house overnight effective in lowering energy usage? It's the same
thing. The energy lost over night has to be made back up in the
morning when it recovers. Following your logic, there would be no
savings. But of course there is. The exact same thing holds true
with the water heater example, but the difference is smaller.

Now, you can argue whether the savings are enough to warrant doing
it. But you can't argue the physics, which you appear to be doing by
your mistatements.

The OP asked whether he would save a substantial amount of money by
buying a timer that shuts off his WH at night. I said no, and I
explained my logic, and I even acknowledged, as you say, that my
reasoning leaves out what I consider to be a very minor detail. I did
that for the sake of *simplicity.* That isn't a contradiction.

Open a physics textbook and you'll find problems that start with
disclaimers: Disregarding air friction is a common one. If you jump off
a 100 foot tall building, how fast will you be moving when you hit the
ground, *disregarding air friction.* Why disregard air friction? Because
in 100 ft., you're still so damn far away from terminal velocity that
air friction can be ignored, for *practical* purposes. And because the
problem as stated doesn't have enough info to include air friction,
either, since we don't know the jumper's posture and therefore frontal
area.

Let's say your HW is at 130 degrees, and it cools to 110 overnight in
the tank with the heater off. Do you *really* think that the slope of
temp over time isn't close enough to linear to disregard its shallowing
in this *real world* consideration?

This isn't a physics course, it's a usenet discussion. Adding in factors
that are so small as to be practically irrelevant has no bearing on the
thing.

When does delta T (ambient vs. water temp) matter, in terms of actually
saving money? I'd say if you turn your setting down from 140 to 120,
you'll save actual money. Maybe not much, but some. The overnight timer,
nuts.

A house is not a water heater. The overwhelming majority of the energy
used to maintain a water heater comes from *using* the hot water and
heating the replacement cold water. You aren't using the air in your
home, it's leaking out.

In article
,
wrote:

On Aug 7, 9:47*am, ransley Mark wrote:
On Aug 6, 8:31*pm, "Jordan" wrote:

I just started thinking about getting an electric water heater timer for
my
3 year old 30 gallon water heater. *I checked some of the reviews for the
Intermatic timers and it looks like everybody loves them and they say
they
practically get their $40 bucks back each month.

Are timers all they seem to be cracked up to be and will turning off the
water heater from 10 PM to 8 AM really save a family of 4 a big chunk of
change each month?

Nobody is getting 40 back, My total bill for the electric tank was
under 40 a month, I know because that is how much it went down when I
switched to Ng. Do a test, my tank still had warm water in it after 5
days when I would leave and turn off the power. See how much it drops
overnight, you will be just reheating it and may save nothing.

Of course it has to be reheated, but once again, that DOES NOT
TRANSLATE INTO SAVING NOTHING. In fact, the more it has to be
reheated, the MORE he saves.

Sorry, not true. It's the change in *rate* of heat loss that determines
the savings. The rate slows, slightly, as the temperature difference
between the water in the tank and the surrounding air decreases. But
that difference is essentially negligible.

IOW, looking at a loss of 20 degrees in 10 hours overnight: if it loses
10 degrees in the first five hours and another 10 in the second five
hours, there is absolutely *zero* savings. However, if it loses 10.1
degrees in the first five hours and 9.9 degrees in the second five
hours, then you'll save by turning it off overnight. How much? Maybe a
penny. Likely not even that.

You do have one good point here, and
that is to measure the water temp one night just before turning it
off, then measure again in the AM before turing it back on. The
smaller the temp drop, the less energy will be saved. That should
give a good indication of how practical it would be. Could it be so
small that it's not worth it? Sure. But that is different than
saying it doesn't actually save any energy at all.




Insulate pipes and the tank, that will save money, turn down the temp
so you only need hot water for a shower, that will save alot.

On Aug 8, 12:16*pm, Smitty Two wrote:
In article
,





wrote:
On Aug 7, 11:50*pm, Smitty Two wrote:
In article ,

*"PanHandler" wrote:
"Smitty Two" wrote in message
news

Sorry, peak hours are *not* at night. I'd venture that 99% of the DOE's
supposed savings is due to a reduction in the price per kwh. Not only
that, they aren't talking about your *total* electric bill, only the
portion of it that the WH accounts for. So the logic behind your $8
savings is flawed.

This problem is a minor modification of the jacuzzi heating question,
and the same logic applies. Every speck of heat lost through the night
has to be replaced. Do it in small chunks, or do it all at once. Same
amount of energy is expended, disregarding the *very* minor difference
noted (that rate of heat loss decreases as temp. differential
decreases.)

Please reply to my earlier post:
Compared to being on all the time, how could it not save me substantially
if
it only runs thirty hours a month? It seems to defy logic.
Thank you.

Perhaps the confusion stems from some ambiguity in the word *on.* An
electric water heater is not *on* all the time anymore than a
refrigerator is *on* all the time, or a motion sensor light.

The refrigerator is triggered to come on when the temperature rises
above a certain threshold. The motion sensor light is triggered to turn
on when motion is detected.

And the water heater is triggered to come on when the water temp falls
below a certain threshold. The fact that it hasn't been "turned off"
doesn't mean that it's consuming electricity.

Let's say that between a shower and other needs, and heat leaking to the
surroundings, your tank loses 50 degrees in 24 hours. And let's say it
can make up that 50 degree loss in an hour.

It will use just as much electricity if it comes on for one hour every
day, making up the whole 50 degrees at once, or if it comes on for six
minutes, 10 times per day, increasing the water temp in the tank 5
degrees each time.- Hide quoted text -

- Show quoted text -

Despite your post acknowledging that this was not true, where you
seemed to recognize your earlier posts were incorrect, here we go
again. * In your above example, yes the water heater uses the same
amount of energy because it runs for only 60 mins either way. * The
big difference is that in the case of the frequent reheating, at the
end, you wind up with a tank of water that is at a slightly lower
temp. * You seem to have a problem confusing what may be practical and/
or worth doing with pure physics. * *The amount of heat loss is
proportional to the temp difference. * If the tank is reheated
frequently, or just left on to maintain the normal temp, the tank will
be losing MORE energy as heat loss. * Therefore at the end of the
period, it either uses more electricity to get to the same temp, or
with the same amount of electricity ends up at a lower final temp.

If things worked as you claimed, why is setting back the temp of a
house overnight effective in lowering energy usage? * *It's the same
thing. * The energy lost over night has to be made back up in the
morning when it recovers. *Following your logic, there would be no
savings. * *But of course there is. * The exact same thing holds true
with the water heater example, but the difference is smaller.

Now, you can argue whether the savings are enough to warrant doing
it. *But you can't argue the physics, which you appear to be doing by
your mistatements.

The OP asked whether he would save a substantial amount of money by
buying a timer that shuts off his WH at night. I said no, and I
explained my logic, and I even acknowledged, as you say, that my
reasoning leaves out what I consider to be a very minor detail. I did
that for the sake of *simplicity.* That isn't a contradiction.\

Here's exactly what you posted:

"I doubt you're saving anything. If you used hot water one day per
week,
then it might save you to shut it off for the other six days. For all
intents and purposes*, you don't save until it's been off long enough
to
cool down to whatever temp your cold water supply is. "


And you logic is clearly flawed. You start saving as the water cools
down and the water heater doesn't come on to start heating it back
up. To state that you don't save anything and that for all intents
and purposes you don't save anything until the water reaches the cold
water supply temp is flat out wrong. If that were true, then turning
back a heating sytem at night when it's 15 degrees out would not save
energy either, until the house got down to 15 degrees inside.


And then you posted this:

Let's say that between a shower and other needs, and heat leaking to
the
surroundings, your tank loses 50 degrees in 24 hours. And let's say
it
can make up that 50 degree loss in an hour.

It will use just as much electricity if it comes on for one hour
every
day, making up the whole 50 degrees at once, or if it comes on for
six
minutes, 10 times per day, increasing the water temp in the tank 5
degrees each time. "

Which again is clearly wrong. Both cases above will use the same
amount of energy because the heater is on for exactly the same amount
of time. But by heating it ten times a day, the water temp in that
case will be slightly LOWER, because by keeping it hotter during the
say, MORE energy is lost through the tank to the surroundings.




Open a physics textbook and you'll find problems that start with
disclaimers: Disregarding air friction is a common one. If you jump off
a 100 foot tall building, how fast will you be moving when you hit the
ground, *disregarding air friction.* Why disregard air friction? Because
in 100 ft., you're still so damn far away from terminal velocity that
air friction can be ignored, for *practical* purposes. And because the
problem as stated doesn't have enough info to include air friction,
either, since we don't know the jumper's posture and therefore frontal
area.

Let's say your HW is at 130 degrees, and it cools to 110 overnight in
the tank with the heater off. Do you *really* think that the slope of
temp over time isn't close enough to linear to disregard its shallowing
in this *real world* consideration?

According to physice, the slope of the temperature decay isn't
linear. It's a natural log function and is actually a great example
of a natural log exponential decay. And even if it were linear, who
cares? The shape of the decay would only effect exactly how much
energy one would save by allowing the tank to cool.



This isn't a physics course, it's a usenet discussion. Adding in factors
that are so small as to be practically irrelevant has no bearing on the
thing.

This isn't some second order irrelevant effect. It's the core of the
whole process and how turning back temp in either your water heater or
your house in winter saves energy. Again, you can argue about how
much energy you will save, whether it's worth it in the case of the
water heater, etc, but to say that you don't save energy at all is
incorrect. To use your physics example, what you are saying would be
like saying because 2 cans sitting on a table don't move toward each
other, gravity doesn't exist between the two masses.



When does delta T (ambient vs. water temp) matter, in terms of actually
saving money? I'd say if you turn your setting down from 140 to 120,
you'll save actual money. Maybe not much, but some. The overnight timer,
nuts.

In the case of the water heater, you actually start saving energy as
soon as the thermostat closes to start re-heating the water, but is
prevented from doing it by the timer, . Is it enough to make it
worthwhile is a different question.



A house is not a water heater. The overwhelming majority of the energy
used to maintain a water heater comes from *using* the hot water and
heating the replacement cold water. You aren't using the air in your
home, it's leaking out.- Hide quoted text -



Heat is lost in a home in a variety of ways and is certainly not
limited to the air leaking out, nor do I believe that is even the
biggest loss in a typical house. Even if the house was perfectly
sealed, there would be substantial loss. That's why we have
insulation instead of just a plastic barrier. And how the heat is
lost doesn't change how the process works. In this case the heat
loss through the water heater tank is exactly the same as the heat
loss in a home through insulated walls, ceiling, etc. In either
case, you save energy because less in heat is loss as the temp goes
down.




- Show quoted text -

In article , Smitty Two wrote:

A house is not a water heater. The overwhelming majority of the energy
used to maintain a water heater comes from *using* the hot water and
heating the replacement cold water. You aren't using the air in your
home, it's leaking out.

How is warm air leaking out of a house -- and consequently being replaced by
colder air leaking in -- meaningfully different from warm water being
withdrawn from a water heater and being replaced by colder water?

On Aug 8, 12:46*pm, Smitty Two wrote:
In article
,





wrote:
On Aug 7, 9:47*am, ransley Mark wrote:
On Aug 6, 8:31*pm, "Jordan" wrote:

I just started thinking about getting an electric water heater timer for
my
3 year old 30 gallon water heater. *I checked some of the reviews for the
Intermatic timers and it looks like everybody loves them and they say
they
practically get their $40 bucks back each month.

Are timers all they seem to be cracked up to be and will turning off the
water heater from 10 PM to 8 AM really save a family of 4 a big chunk of
change each month?

Nobody is getting 40 back, My total bill for the electric tank was
under 40 a month, I know because that is how much it went down when I
switched to Ng. Do a test, my tank still had warm water in it after 5
days when I would leave and turn off the power. See how much it drops
overnight, you will be just reheating it and may save nothing.

Of course it has to be reheated, but once again, that DOES NOT
TRANSLATE INTO SAVING NOTHING. * In fact, the more it has to be
reheated, the MORE he saves.

Sorry, not true. It's the change in *rate* of heat loss that determines
the savings. The rate slows, slightly, as the temperature difference
between the water in the tank and the surrounding air decreases. But
that difference is essentially negligible.

IOW, looking at a loss of 20 degrees in 10 hours overnight: if it loses
10 degrees in the first five hours and another 10 in the second five
hours, there is absolutely *zero* savings. However, if it loses 10.1
degrees in the first five hours and 9.9 degrees in the second five
hours, then you'll save by turning it off overnight. How much? Maybe a
penny. Likely not even that.



*You do have one good point here, and
that is to measure the water temp one night just before turning it
off, then measure again in the AM before turing it back on. *The
smaller the temp drop, the less energy will be saved. *That should
give a good indication of how practical it would be. *Could it be so
small that it's not worth it? * Sure. * But that is different than
saying it doesn't actually save any energy at all.

Insulate pipes and the tank, that will save money, turn down the temp
so you only need hot water for a shower, that will save alot.- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

On Aug 8, 12:46*pm, Smitty Two wrote:
In article
,





wrote:
On Aug 7, 9:47*am, ransley Mark wrote:
On Aug 6, 8:31*pm, "Jordan" wrote:

I just started thinking about getting an electric water heater timer for
my
3 year old 30 gallon water heater. *I checked some of the reviews for the
Intermatic timers and it looks like everybody loves them and they say
they
practically get their $40 bucks back each month.

Are timers all they seem to be cracked up to be and will turning off the
water heater from 10 PM to 8 AM really save a family of 4 a big chunk of
change each month?

Nobody is getting 40 back, My total bill for the electric tank was
under 40 a month, I know because that is how much it went down when I
switched to Ng. Do a test, my tank still had warm water in it after 5
days when I would leave and turn off the power. See how much it drops
overnight, you will be just reheating it and may save nothing.

Of course it has to be reheated, but once again, that DOES NOT
TRANSLATE INTO SAVING NOTHING. * In fact, the more it has to be
reheated, the MORE he saves.

Sorry, not true.

Exactly what is not true? This is what you stated:

"See how much it drops overnight, you will be just reheating it and
may save nothing.
'

That is what is not true and doesn't make any sense. Of course it has
to be reheated the next morning. The point, once again, is that it
takes less energy to then reheat it in the morning than it does to
maintain it at the normal set temp all night. This is exactly the
same concept and simple physics as turning back a thermostat overnight
on a home heating system. Are you going to tell us that doesn't save
energy too?

And again, let me state the disclaimer, I'm not saying he's going to
save a lot of energy. I'm not saying it's worth it to install a
timer. Maybe it is, maybe it isn't depending on exactly how much
energy he can save. But that is a totally different argument than
saying turning off the water heater doesn't save any energy because it
has to be reheated.

It's the change in *rate* of heat loss that determines
the savings. The rate slows, slightly, as the temperature difference
between the water in the tank and the surrounding air decreases. But
that difference is essentially negligible.

IOW, looking at a loss of 20 degrees in 10 hours overnight: if it loses
10 degrees in the first five hours and another 10 in the second five
hours, there is absolutely *zero* savings.


Let's look at the previous example you gave he

Let's say your HW is at 130 degrees, and it cools to 110 overnight in
the tank with the heater off. Do you *really* think that the slope of
temp over time isn't close enough to linear to disregard its
shallowing
in this *real world* consideration?


The rate of heat loss is proportional to the temp difference. Let's
assume it's in a basement at 60 degrees. At 130 degrees, the temp
differential is 130-60, or 70 degrees. At 110, it's 110-60 or 50
degrees. So the temperature differential has gone from 70 to 50, or
about a 30% difference at the end of the period. It's a decaying
exponential so more of that 30% benefit occurs in the earlier period
than in the later. But even if you assumed it was linear and went
from 0 decrease to 30% at the end of the period, the tank would have
an average of about 15% less heat loss over say 6 hours. That isn't
zero and it's not negligible either. Again, whether it makes it
worthwhile to install a timer is a completely different discussion.



However, if it loses 10.1
degrees in the first five hours and 9.9 degrees in the second five
hours, then you'll save by turning it off overnight. How much? Maybe a
penny. Likely not even that.



Clearly that can't happen. because the rate of heat loss is
proportional to the temp difference and it's a natural log decaying
function, which according to physics and math isn't close to being
linear. In other words, it's going to lose much less in the second
five hours.

On Thu, 7 Aug 2008 17:25:50 -0700, "Bob F"
wrote:


"Andy Asberry" wrote in message
.. .


I believe you are on the right track. I have nothing to back up my
theory but here goes. It seems to me you only save after the tank
water temp has cooled to incoming water temp. Then the time off would
be the same as never having turned it on. This, assuming you have done
the other things such as insulation and stopping leaks.

How many times in this thread have you made the same, obviously erronious claim?
You save any time the water in the tank remians cooler than normal. In many
places, the water would NEVER even reach the incoming water temp, which is lower
than room temp.


Well, gosh genius. How hard is it to count up to one?

I prefaced my remark (NOT claim) by stating I had nothing to back it
up. That means no reference or formal education. Perhaps, I should
have said "when the tank water has stopping losing heat" instead of
saying "tank water temp has cooled to incoming water temp".

On the other hand, you erroneously assume that incoming water temp is
lower than room temp. I haven't used any heated water to shower for
the last month here where it has been over a 100 degrees every day.
400 feet of water line buried only 8" deep is heated nicely by ol'
Sol.

Your theory may well be correct. If you're not winning any converts
perhaps you should reconsider your delivery.

--Andy Asberry--
------Texas-----

In article
,
wrote:

On Aug 8, 12:46*pm, Smitty Two wrote:
In article
,





wrote:
On Aug 7, 9:47*am, ransley Mark wrote:
On Aug 6, 8:31*pm, "Jordan" wrote:

I just started thinking about getting an electric water heater timer
for
my
3 year old 30 gallon water heater. *I checked some of the reviews for
the
Intermatic timers and it looks like everybody loves them and they say
they
practically get their $40 bucks back each month.

Are timers all they seem to be cracked up to be and will turning off
the
water heater from 10 PM to 8 AM really save a family of 4 a big chunk
of
change each month?

Nobody is getting 40 back, My total bill for the electric tank was
under 40 a month, I know because that is how much it went down when I
switched to Ng. Do a test, my tank still had warm water in it after 5
days when I would leave and turn off the power. See how much it drops
overnight, you will be just reheating it and may save nothing.

Of course it has to be reheated, but once again, that DOES NOT
TRANSLATE INTO SAVING NOTHING. * In fact, the more it has to be
reheated, the MORE he saves.

Sorry, not true.

Exactly what is not true? This is what you stated:

"See how much it drops overnight, you will be just reheating it and
may save nothing.

I didn't say that. We're getting into quote confusion, now.

'

That is what is not true and doesn't make any sense. Of course it has
to be reheated the next morning. The point, once again, is that it
takes less energy to then reheat it in the morning than it does to
maintain it at the normal set temp all night. This is exactly the
same concept and simple physics as turning back a thermostat overnight
on a home heating system. Are you going to tell us that doesn't save
energy too?

And again, let me state the disclaimer, I'm not saying he's going to
save a lot of energy. I'm not saying it's worth it to install a
timer. Maybe it is, maybe it isn't depending on exactly how much
energy he can save. But that is a totally different argument than
saying turning off the water heater doesn't save any energy because it
has to be reheated.

It's the change in *rate* of heat loss that determines
the savings. The rate slows, slightly, as the temperature difference
between the water in the tank and the surrounding air decreases. But
that difference is essentially negligible.

IOW, looking at a loss of 20 degrees in 10 hours overnight: if it loses
10 degrees in the first five hours and another 10 in the second five
hours, there is absolutely *zero* savings.


Let's look at the previous example you gave he

Let's say your HW is at 130 degrees, and it cools to 110 overnight in
the tank with the heater off. Do you *really* think that the slope of
temp over time isn't close enough to linear to disregard its
shallowing
in this *real world* consideration?


The rate of heat loss is proportional to the temp difference. Let's
assume it's in a basement at 60 degrees. At 130 degrees, the temp
differential is 130-60, or 70 degrees. At 110, it's 110-60 or 50
degrees. So the temperature differential has gone from 70 to 50, or
about a 30% difference at the end of the period. It's a decaying
exponential so more of that 30% benefit occurs in the earlier period
than in the later. But even if you assumed it was linear and went
from 0 decrease to 30% at the end of the period, the tank would have
an average of about 15% less heat loss over say 6 hours. That isn't
zero and it's not negligible either. Again, whether it makes it
worthwhile to install a timer is a completely different discussion.



However, if it loses 10.1
degrees in the first five hours and 9.9 degrees in the second five
hours, then you'll save by turning it off overnight. How much? Maybe a
penny. Likely not even that.



Clearly that can't happen. because the rate of heat loss is
proportional to the temp difference and it's a natural log decaying
function, which according to physics and math isn't close to being
linear. In other words, it's going to lose much less in the second
five hours.

I'm pretty sure that if you look at a short enough section of a
logarithmic curve, it approaches a straight line. I think the WH cooling
graph overnight fits that approximation. Yes, it's an approximation. I
was the first one to acknowledge that I am approximating. So what?

Show me some data that says a well-insulated tank in a heated area of a
house loses so much heat overnight that a person could save any
significant amount of money. Otherwise, let's just agree to disagree on
this one.

In article ,
(Doug Miller) wrote:

In article , Smitty Two
wrote:

A house is not a water heater. The overwhelming majority of the energy
used to maintain a water heater comes from *using* the hot water and
heating the replacement cold water. You aren't using the air in your
home, it's leaking out.

How is warm air leaking out of a house -- and consequently being replaced by
colder air leaking in -- meaningfully different from warm water being
withdrawn from a water heater and being replaced by colder water?

The only one who coughed up anecdotal numbers from the real world in
this thread said his electric bill went down by $40 when he switched
from electricity to NG to heat his water.

Let's say 90% of that money went to heating cold water coming in, which
replaced the warm water going out. And 10% of that money went to making
up for "unintentional" heat loss.

That's $4, total cost of unwanted heat loss. And let's say that turning
off the WH at night saves, oh, maybe 5% of the energy that leaving it on
all night uses. The OP defined all night as 10 hours.
(10/24)(0.05)($4.00) = $0.08.

I stand corrected. I said the OP couldn't save a plug nickel. My new
position is, he could save *eight cents per month.*

On second thought, I bet the timer costs .08 to run every month. I'm
going back to my plug nickel assertion.

You seem like a smart guy, Doug. I think you can figure out what I mean
when I say turning off a WH isn't the same as turning down the house
heat at night.

In article , Smitty Two wrote:
In article ,
(Doug Miller) wrote:

In article , Smitty Two
wrote:

A house is not a water heater. The overwhelming majority of the energy
used to maintain a water heater comes from *using* the hot water and
heating the replacement cold water. You aren't using the air in your
home, it's leaking out.

How is warm air leaking out of a house -- and consequently being replaced by
colder air leaking in -- meaningfully different from warm water being
withdrawn from a water heater and being replaced by colder water?

The only one who coughed up anecdotal numbers from the real world in
this thread said his electric bill went down by $40 when he switched
from electricity to NG to heat his water.

Plausible IMHO.

Let's say 90% of that money went to heating cold water coming in, which
replaced the warm water going out. And 10% of that money went to making
up for "unintentional" heat loss.

Also plausible.

That's $4, total cost of unwanted heat loss. And let's say that turning
off the WH at night saves, oh, maybe 5% of the energy that leaving it on
all night uses. The OP defined all night as 10 hours.
(10/24)(0.05)($4.00) = $0.08.

I wonder at your guesstimate of 5% ...

I stand corrected. I said the OP couldn't save a plug nickel. My new
position is, he could save *eight cents per month.*

... just off the cuff, I'd regard 20% as a more plausible figure -- which
brings the savings all the way up to a penny a day. Those pennies add up, you
know. ;-)

On second thought, I bet the timer costs .08 to run every month. I'm
going back to my plug nickel assertion.

Depends on which guesstimate is closer to correct: your 5%, or my 20%. I just
had a look at the Dayton Electric Timer which was left here by the previous
owner; it has a 3-watt motor. 3w * 24 hrs/day * 30 days/mo = 2160 watt-hrs/mo
= just over 2 kwh per month. Assume ten cents / kwh; at 5%, you're wasting
money, but at 20% you're saving. Not much, admittedly, but still non-zero.

I'll let you work out how long it takes to recoup the cost of the timer. :-)

You seem like a smart guy, Doug. I think you can figure out what I mean
when I say turning off a WH isn't the same as turning down the house
heat at night.

If by that you mean -- yes, the two situations operate on the same principle
exactly, but the amount of money saved on the water heater is so small as to
be not worth consideration -- then we agree. If you mean something other than
that, then we probably disagree.

"Jordan" wrote in message
. ..
I just started thinking about getting an electric water heater timer for my
3 year old 30 gallon water heater. I checked some of the reviews for the
Intermatic timers and it looks like everybody loves them and they say they
practically get their $40 bucks back each month.

Are timers all they seem to be cracked up to be and will turning off the
water heater from 10 PM to 8 AM really save a family of 4 a big chunk of
change each month?



I tried the timer, elec bill went UP. The water was cooling too much in the
off cycles, then the WH had to run like hell to catch back up.