This is a new issue for me. Daughter bought new home this summer, a
two-story brick 4500 sq ft. Gas heat, two separate systems, with
laundry and gas heater on second story. Washer and dryer on second
story, in bonus room above garage. Busy with t-giving and didn't look
hard enough for trouble, but when she told me what was going on I got
alarmed.....garage still has stuff not moved into the house yet, and is
good path for three dogs in and out of house so it stays open. Not real
detail oriented cause they are more into bigger projects ) So,
daughter tells me her washer won't work when it is real cold
out....commercial type, brand unknown. Well, did you try running water
upstairs first? Adjust temp setting on washer? Nothing worked until it
warmed up outdoors. So, we go exploring....in corner of garage, back
side of fireplace, is inset covered with pegboard...all utils to 2nd
story apparently go up there. At base of pegboard are two happy little
water shutoff valves! There appears to be a water stain all the way
down from top to the valves........good grief.....brain cells start
firing......the house two doors down, same size and design, has had a
dumpster parked out front for months, repairing flood damage from broken
pipe. So, questions....is heat tape a good idea on these water pipes?
Matter whether copper or pvc? Different types of heat tape? I've read
of alarms...go on a main line or just appliance? Recommendations from
experience would be appreciated. (Yeah, she is leaving the heater on in
the garage....might have to have one or two teenagers go without food.
They have four.)

On Thursday, December 4, 2014 7:47:24 AM UTC-5, NorMinn wrote:
This is a new issue for me. Daughter bought new home this summer, a
two-story brick 4500 sq ft. Gas heat, two separate systems, with
laundry and gas heater on second story. Washer and dryer on second
story, in bonus room above garage. Busy with t-giving and didn't look
hard enough for trouble, but when she told me what was going on I got
alarmed.....garage still has stuff not moved into the house yet, and is
good path for three dogs in and out of house so it stays open. Not real
detail oriented cause they are more into bigger projects ) So,
daughter tells me her washer won't work when it is real cold
out....commercial type, brand unknown. Well, did you try running water
upstairs first? Adjust temp setting on washer? Nothing worked until it
warmed up outdoors. So, we go exploring....in corner of garage, back
side of fireplace, is inset covered with pegboard...all utils to 2nd
story apparently go up there. At base of pegboard are two happy little
water shutoff valves! There appears to be a water stain all the way
down from top to the valves........good grief.....brain cells start
firing......the house two doors down, same size and design, has had a
dumpster parked out front for months, repairing flood damage from broken
pipe. So, questions....is heat tape a good idea on these water pipes?
Matter whether copper or pvc? Different types of heat tape? I've read
of alarms...go on a main line or just appliance? Recommendations from
experience would be appreciated. (Yeah, she is leaving the heater on in
the garage....might have to have one or two teenagers go without food.
They have four.)

The first obvious thing to do is keept the garage door closed when it's
cold outside. Even if it's used to let the dogs out, it can be opened,
then closed again. Having it open must also be adding to the heating costs
for the living space.

Heat tape is an option. I'd get the better, self-regulating type, where
the resistance changes according to temperature, so it uses more power
when it gets real cold, less when it's warmer. They also have small plug-in
thermostats designed to turn on when the temp gets close to freezing.
Google EH38. But I've seen reports that they may not be real reliable, so
use diligence. I've got some experience, less that a year with one, and
it's working OK. For that application, probably better to just plug it
in and leave it on, with the self-regulating, it's not going to use that
much energy.

You might also replace that section of pipe with PEX. Apparently PEX
can also freeze and burst, but I understand it's more resistant than
copper or PVC. The problem you have of course is that the pipe is
apparently behind a wall. So, it's not too attractive to put heat tape
on something and then seal the wall back up. IDK what the climate is
there. You say there is a fireplace on the other side, so it's apparently
facing the living space on that side? If so, depending on how cold it
gets, just putting insulation between the pipes and the garage sheetrock
might be sufficient.

On 12/4/2014 8:46 AM, trader_4 wrote:
On Thursday, December 4, 2014 7:47:24 AM UTC-5, NorMinn wrote:
This is a new issue for me. Daughter bought new home this summer, a
two-story brick 4500 sq ft. Gas heat, two separate systems, with
laundry and gas heater on second story. Washer and dryer on second
story, in bonus room above garage. Busy with t-giving and didn't look
hard enough for trouble, but when she told me what was going on I got
alarmed.....garage still has stuff not moved into the house yet, and is
good path for three dogs in and out of house so it stays open. Not real
detail oriented cause they are more into bigger projects ) So,
daughter tells me her washer won't work when it is real cold
out....commercial type, brand unknown. Well, did you try running water
upstairs first? Adjust temp setting on washer? Nothing worked until it
warmed up outdoors. So, we go exploring....in corner of garage, back
side of fireplace, is inset covered with pegboard...all utils to 2nd
story apparently go up there. At base of pegboard are two happy little
water shutoff valves! There appears to be a water stain all the way
down from top to the valves........good grief.....brain cells start
firing......the house two doors down, same size and design, has had a
dumpster parked out front for months, repairing flood damage from broken
pipe. So, questions....is heat tape a good idea on these water pipes?
Matter whether copper or pvc? Different types of heat tape? I've read
of alarms...go on a main line or just appliance? Recommendations from
experience would be appreciated. (Yeah, she is leaving the heater on in
the garage....might have to have one or two teenagers go without food.
They have four.)

The first obvious thing to do is keept the garage door closed when it's
cold outside. Even if it's used to let the dogs out, it can be opened,
then closed again. Having it open must also be adding to the heating costs
for the living space.

Heat tape is an option. I'd get the better, self-regulating type, where
the resistance changes according to temperature, so it uses more power
when it gets real cold, less when it's warmer. They also have small plug-in
thermostats designed to turn on when the temp gets close to freezing.
Google EH38. But I've seen reports that they may not be real reliable, so
use diligence. I've got some experience, less that a year with one, and
it's working OK. For that application, probably better to just plug it
in and leave it on, with the self-regulating, it's not going to use that
much energy.

You might also replace that section of pipe with PEX. Apparently PEX
can also freeze and burst, but I understand it's more resistant than
copper or PVC. The problem you have of course is that the pipe is
apparently behind a wall. So, it's not too attractive to put heat tape
on something and then seal the wall back up. IDK what the climate is
there. You say there is a fireplace on the other side, so it's apparently
facing the living space on that side? If so, depending on how cold it
gets, just putting insulation between the pipes and the garage sheetrock
might be sufficient.

The space with the pipes is brick on the living side (interior of living
room) and open in the garage and with the open side covered with peg board.

Of course it will be kept closed, now that the problem is apparent.
With water stains on the pegboard, I'm hoping the feezing hasn't caused
a leak already. Heating the 3car garage will definitely help keep
upstairs warmer.

On 12/4/2014 7:47 AM, Norminn wrote:
This is a new issue for me. Daughter bought new home this summer, a
two-story brick 4500 sq ft. Gas heat, two separate systems, with
laundry and gas heater on second story. Washer and dryer on second
story, in bonus room above garage. Busy with t-giving and didn't look
hard enough for trouble, but when she told me what was going on I got
alarmed.....garage still has stuff not moved into the house yet, and is
good path for three dogs in and out of house so it stays open. Not real
detail oriented cause they are more into bigger projects ) So,
daughter tells me her washer won't work when it is real cold
out....commercial type, brand unknown. Well, did you try running water
upstairs first? Adjust temp setting on washer? Nothing worked until it
warmed up outdoors. So, we go exploring....in corner of garage, back
side of fireplace, is inset covered with pegboard...all utils to 2nd
story apparently go up there. At base of pegboard are two happy little
water shutoff valves! There appears to be a water stain all the way
down from top to the valves........good grief.....brain cells start
firing......the house two doors down, same size and design, has had a
dumpster parked out front for months, repairing flood damage from broken
pipe. So, questions....is heat tape a good idea on these water pipes?
Matter whether copper or pvc? Different types of heat tape? I've read
of alarms...go on a main line or just appliance? Recommendations from
experience would be appreciated. (Yeah, she is leaving the heater on in
the garage....might have to have one or two teenagers go without food.
They have four.)

Not sure about your specifics, but I've seen pipe
foam wrap sold in hardware stores. It's possible
that self regulating heater tape inside of foam
wrap can help. Heater tape needs contact with the
pipe (I think?; read the package). So figure for a
lot of nylon tie wraps, or a lot of tape.

If the hot and cold pipes close to each other, may
be able to bind them together and use one heat tape,
and one foam wrap.

Your small town hardware guys likely to know all
this kind of thing.



--
..
Christopher A. Young
Learn about Jesus
www.lds.org
..

Norminn wrote:
This is a new issue for me. Daughter bought new home this summer, a
two-story brick 4500 sq ft. Gas heat, two separate systems, with
laundry and gas heater on second story. Washer and dryer on second
story, in bonus room above garage. Busy with t-giving and didn't look
hard enough for trouble, but when she told me what was going on I got
alarmed.....garage still has stuff not moved into the house yet, and is
good path for three dogs in and out of house so it stays open. Not real
detail oriented cause they are more into bigger projects ) So,
daughter tells me her washer won't work when it is real cold
out....commercial type, brand unknown. Well, did you try running water
upstairs first? Adjust temp setting on washer? Nothing worked until it
warmed up outdoors. So, we go exploring....in corner of garage, back
side of fireplace, is inset covered with pegboard...all utils to 2nd
story apparently go up there. At base of pegboard are two happy little
water shutoff valves! There appears to be a water stain all the way
down from top to the valves........good grief.....brain cells start
firing......the house two doors down, same size and design, has had a
dumpster parked out front for months, repairing flood damage from broken
pipe. So, questions....is heat tape a good idea on these water pipes?
Matter whether copper or pvc? Different types of heat tape? I've read
of alarms...go on a main line or just appliance? Recommendations from
experience would be appreciated. (Yeah, she is leaving the heater on in
the garage....might have to have one or two teenagers go without food.
They have four.)
Hmm
What a big house. How old? Location? I hate any room above garage, never
had one in every house I built.

"Norminn" wrote in message
...
This is a new issue for me. Daughter bought new home this summer, a
two-story brick 4500 sq ft. Gas heat, two separate systems, with laundry
and gas heater on second story. Washer and dryer on second story, in
bonus room above garage. Busy with t-giving and didn't look hard enough
for trouble, but when she told me what was going on I got
alarmed.....garage still has stuff not moved into the house yet, and is
good path for three dogs in and out of house so it stays open. Not real
detail oriented cause they are more into bigger projects ) So, daughter
tells me her washer won't work when it is real cold out....commercial
type, brand unknown. Well, did you try running water upstairs first?
Adjust temp setting on washer? Nothing worked until it warmed up
outdoors. So, we go exploring....in corner of garage, back side of
fireplace, is inset covered with pegboard...all utils to 2nd story
apparently go up there. At base of pegboard are two happy little water
shutoff valves! There appears to be a water stain all the way down from
top to the valves........good grief.....brain cells start firing......the
house two doors down, same size and design, has had a dumpster parked out
front for months, repairing flood damage from broken pipe. So,
questions....is heat tape a good idea on these water pipes? Matter whether
copper or pvc? Different types of heat tape? I've read of alarms...go on
a main line or just appliance? Recommendations from experience would be
appreciated. (Yeah, she is leaving the heater on in the garage....might
have to have one or two teenagers go without food. They have four.)


Just move somewhere it doesn't freeze.

On Thu, 04 Dec 2014 07:47:29 -0500, Norminn
wrote:

water shutoff valves! There appears to be a water stain all the way
down from top to the valves........good grief.....brain cells start
firing......the house two doors down, same size and design, has had a
dumpster parked out front for months, repairing flood damage from broken
pipe. So, questions....is heat tape a good idea on these water pipes?

It cudn't hoyt.

Take the same care with the hot water pipes you do with the cold. It
turns out hot water pipes can freeze sooner than cold water.


Matter whether copper or pvc? Different types of heat tape? I've read
of alarms...go on a main line or just appliance? Recommendations from
experience would be appreciated. (Yeah, she is leaving the heater on in
the garage....might have to have one or two teenagers go without food.

They grow too tall these days anyhow. Less food will do them good.

They have four.)

On Thursday, December 4, 2014 10:42:17 AM UTC-5, NorMinn wrote:
On 12/4/2014 8:46 AM, trader_4 wrote:
On Thursday, December 4, 2014 7:47:24 AM UTC-5, NorMinn wrote:
This is a new issue for me. Daughter bought new home this summer, a
two-story brick 4500 sq ft. Gas heat, two separate systems, with
laundry and gas heater on second story. Washer and dryer on second
story, in bonus room above garage. Busy with t-giving and didn't look
hard enough for trouble, but when she told me what was going on I got
alarmed.....garage still has stuff not moved into the house yet, and is
good path for three dogs in and out of house so it stays open. Not real
detail oriented cause they are more into bigger projects ) So,
daughter tells me her washer won't work when it is real cold
out....commercial type, brand unknown. Well, did you try running water
upstairs first? Adjust temp setting on washer? Nothing worked until it
warmed up outdoors. So, we go exploring....in corner of garage, back
side of fireplace, is inset covered with pegboard...all utils to 2nd
story apparently go up there. At base of pegboard are two happy little
water shutoff valves! There appears to be a water stain all the way
down from top to the valves........good grief.....brain cells start
firing......the house two doors down, same size and design, has had a
dumpster parked out front for months, repairing flood damage from broken
pipe. So, questions....is heat tape a good idea on these water pipes?
Matter whether copper or pvc? Different types of heat tape? I've read
of alarms...go on a main line or just appliance? Recommendations from
experience would be appreciated. (Yeah, she is leaving the heater on in
the garage....might have to have one or two teenagers go without food.
They have four.)

The first obvious thing to do is keept the garage door closed when it's
cold outside. Even if it's used to let the dogs out, it can be opened,
then closed again. Having it open must also be adding to the heating costs
for the living space.

Heat tape is an option. I'd get the better, self-regulating type, where
the resistance changes according to temperature, so it uses more power
when it gets real cold, less when it's warmer. They also have small plug-in
thermostats designed to turn on when the temp gets close to freezing.
Google EH38. But I've seen reports that they may not be real reliable, so
use diligence. I've got some experience, less that a year with one, and
it's working OK. For that application, probably better to just plug it
in and leave it on, with the self-regulating, it's not going to use that
much energy.

You might also replace that section of pipe with PEX. Apparently PEX
can also freeze and burst, but I understand it's more resistant than
copper or PVC. The problem you have of course is that the pipe is
apparently behind a wall. So, it's not too attractive to put heat tape
on something and then seal the wall back up. IDK what the climate is
there. You say there is a fireplace on the other side, so it's apparently
facing the living space on that side? If so, depending on how cold it
gets, just putting insulation between the pipes and the garage sheetrock
might be sufficient.

The space with the pipes is brick on the living side (interior of living
room) and open in the garage and with the open side covered with peg board.


It seeems a bit odd that it's a new house with a garage wall covered with
just peg board, ie no sheetrock? The brick wall would provide a fire block
to the living space on the other side of that wall. But then pipes obviously
runup through it to the living space above the garage and the holes for those pipes would provide a path for fumes, fire, etc from the garage to get to the
living space. I don't think it would pass code here.


Of course it will be kept closed, now that the problem is apparent.
With water stains on the pegboard, I'm hoping the feezing hasn't caused
a leak already. Heating the 3car garage will definitely help keep
upstairs warmer.

What heating? And the ceiling of the garage should be insulated.

On Thursday, December 4, 2014 5:12:54 PM UTC-5, micky wrote:
Take the same care with the hot water pipes you do with the cold. It
turns out hot water pipes can freeze sooner than cold water.


I'm familiar with the Mpemba effect, but didn't know it applied to water pipes. Is there evidence for this?

On Friday, December 5, 2014 8:53:57 AM UTC-5, TimR wrote:
On Thursday, December 4, 2014 5:12:54 PM UTC-5, micky wrote:
Take the same care with the hot water pipes you do with the cold. It
turns out hot water pipes can freeze sooner than cold water.


I'm familiar with the Mpemba effect, but didn't know it applied to water pipes. Is there evidence for this?

I can think of an easy way for a hot water pipe to freeze before a
cold water pipe. In the case we have here, where the living space is
pulling water through a cold garage, if a hot water faucet hasn't been
turned on for 6 hours, while the cold water faucet has drawn water every
hour, then if the garage is say 20F, the hot water pipe will freeze first.

The Mpemba effect may exist, in some special cases, but I think most of
the reported Mpemba effect examples are the result of anecdotal stories and
poorly constructed experiments.

On Fri, 5 Dec 2014 05:53:54 -0800 (PST), TimR
wrote:

On Thursday, December 4, 2014 5:12:54 PM UTC-5, micky wrote:
Take the same care with the hot water pipes you do with the cold. It
turns out hot water pipes can freeze sooner than cold water.


I'm familiar with the Mpemba effect, but didn't know it applied to water pipes. Is there evidence for this?
I doubt there is any solid evidence to back up this "old wive's
tale"

On Friday, December 5, 2014 12:20:31 PM UTC-5, wrote:
On Fri, 5 Dec 2014 05:53:54 -0800 (PST), TimR
wrote:

On Thursday, December 4, 2014 5:12:54 PM UTC-5, micky wrote:
Take the same care with the hot water pipes you do with the cold. It
turns out hot water pipes can freeze sooner than cold water.


I'm familiar with the Mpemba effect, but didn't know it applied to water pipes. Is there evidence for this?
I doubt there is any solid evidence to back up this "old wive's
tale"

I'm a born skeptic, but this time there might be something to it. There are a lot of anectdotal reports from plumbers and homeowners who say their hot water pipes froze first.

The Mpemba effect is proven, there is no doubt about hot water freezing faster in certain circumstances. My question was whether those would include domestic water pipes.

There certainly is a suggestion they can.

There are several hypotheses for why. The hot water heater removes dissolved gases as well as minerals, causing the freezing point to be lower; the hot water pipes are not often used during the night whereas most people are up to the toilet or sink and run the cold water occasionally; the hot water has more temperature gradients within it and transfers heat better. Nobody is sure. I would certainly protect both sets of pipes during cold weather.

Or, add a recirculation pump. That ought to make you immune.

On Fri, 5 Dec 2014 05:53:54 -0800 (PST), TimR
wrote:

On Thursday, December 4, 2014 5:12:54 PM UTC-5, micky wrote:
Take the same care with the hot water pipes you do with the cold. It
turns out hot water pipes can freeze sooner than cold water.


I'm familiar with the Mpemba effect, but didn't know it applied to water pipes. Is there evidence for this?

I think I first heard about it on this ng, wrt water pipes. It wasn't
called by any special name then, so to search for the post one would
have to look for freeze or frozen and hold and cold water and pipe, and
it's probably not worth it. I don't remember for sure if the poster was
telling about what he heard or what he had happen at his own home.

I think it's for real. Wikip gives a bunch or reports for this as far
back as Aristotle and including Francis Bacon and Descartes.

Wikip things the definition of freezing is important. Agreement on what
is freezing would be important to duplicate these earlier reports, but
it's not important otherwise. Whatever definition is used for hot water
should be used for cold water, Duh.

Of course if you leave the cold water running and don't run the hot
water until it freezes, the hot water will freeze first. No one is
talking about that. It certainly seems possible to me that when water
is heated it changes physically so that it then cools more quickly.
That's a lot less strange than 1000 other things that happen on earth.
I've never been close enough to a bunch of water molecules to see what
happens.

How long the Mpemba effect would last I don't know. If the water bursts
from the pipe, fills the yard, seeps into the drit, makes its way to the
stream, the river, the ocean, and is evaporated by the sun, and then
falls as rain, would that water drawn from a spring, lake, or well still
freeze more quickly than water which had never been heated? We should
use radio transmitters like they use for wild animals to track
individual molecules of water so we can be sure. And how much of the
water in the world has been heated artificially, with fire or electric
heat, above the maximum outdoor temperature. Doesn't someone know what
fraction of all the water that is?

On 12/5/2014 1:47 PM, TimR wrote:
On Friday, December 5, 2014 12:20:31 PM UTC-5, wrote:
On Fri, 5 Dec 2014 05:53:54 -0800 (PST), TimR
wrote:

On Thursday, December 4, 2014 5:12:54 PM UTC-5, micky wrote:
Take the same care with the hot water pipes you do with the cold. It
turns out hot water pipes can freeze sooner than cold water.


I'm familiar with the Mpemba effect, but didn't know it applied to water pipes. Is there evidence for this?
I doubt there is any solid evidence to back up this "old wive's
tale"

I'm a born skeptic, but this time there might be something to it. There are a lot of anectdotal reports from plumbers and homeowners who say their hot water pipes froze first.

The Mpemba effect is proven, there is no doubt about hot water freezing faster in certain circumstances. My question was whether those would include domestic water pipes.

There certainly is a suggestion they can.

There are several hypotheses for why. The hot water heater removes dissolved gases as well as minerals, causing the freezing point to be lower; the hot water pipes are not often used during the night whereas most people are up to the toilet or sink and run the cold water occasionally; the hot water has more temperature gradients within it and transfers heat better. Nobody is sure. I would certainly protect both sets of pipes during cold weather.

Or, add a recirculation pump. That ought to make you immune.


HW pipes freeze first because there is less water in them?

On Friday, December 5, 2014 1:47:54 PM UTC-5, TimR wrote:
On Friday, December 5, 2014 12:20:31 PM UTC-5, wrote:
On Fri, 5 Dec 2014 05:53:54 -0800 (PST), TimR
wrote:

On Thursday, December 4, 2014 5:12:54 PM UTC-5, micky wrote:
Take the same care with the hot water pipes you do with the cold. It
turns out hot water pipes can freeze sooner than cold water.


I'm familiar with the Mpemba effect, but didn't know it applied to water pipes. Is there evidence for this?
I doubt there is any solid evidence to back up this "old wive's
tale"

I'm a born skeptic, but this time there might be something to it. There are a lot of anectdotal reports from plumbers and homeowners who say their hot water pipes froze first.

The Mpemba effect is proven, there is no doubt about hot water freezing faster in certain circumstances. My question was whether those would include domestic water pipes.


AFAIK, there is no agreement in the scientific community that this effect
is real and repeatable. It's kind of like cold fusion, some people report something, others can't repeat it, etc. Certainly the broad, general claims
that Mpemba himself made, that hot liquids generally freeze faster, that it's easily demonstrated, is BS. I just tried a simple experiment myself. I took two shot glasses,filled one with tap temp water, the other with water from a pan on the stove that was just starting to steam, but not boiling yet. I put
them both in the freezer, which do you think froze first?




There certainly is a suggestion they can.

There are several hypotheses for why. The hot water heater removes dissolved gases as well as minerals, causing the freezing point to be lower;

It would be trivial to conduct an experiment to rule this in or out,
as well as many other hypothetical causes. It's hard to imagine that in
many decades it hasn't been done.




the hot water pipes are not often used during the night whereas most people are up to the toilet or sink and run the cold water occasionally;

Now you're conflating easily explainable everyday effects with
the M effect. I suspect that's what's happening in the vast majority of the
alleged M effect instances and probably what happened in the original
M case to begin with.



the hot water has more temperature gradients within it and transfers heat better. Nobody is sure.





I would certainly protect both sets of pipes during cold weather.

Of course, that's what everyone does anyway.



Or, add a recirculation pump. That ought to make you immune.

On Friday, December 5, 2014 4:52:30 PM UTC-5, micky wrote:
On Fri, 5 Dec 2014 05:53:54 -0800 (PST), TimR
wrote:

On Thursday, December 4, 2014 5:12:54 PM UTC-5, micky wrote:
Take the same care with the hot water pipes you do with the cold. It
turns out hot water pipes can freeze sooner than cold water.


I'm familiar with the Mpemba effect, but didn't know it applied to water pipes. Is there evidence for this?

I think I first heard about it on this ng, wrt water pipes. It wasn't
called by any special name then, so to search for the post one would
have to look for freeze or frozen and hold and cold water and pipe, and
it's probably not worth it. I don't remember for sure if the poster was
telling about what he heard or what he had happen at his own home.

I think it's for real. Wikip gives a bunch or reports for this as far
back as Aristotle and including Francis Bacon and Descartes.


Go repeat the shot glass experiment in my previous post. Let us know
the results.


Wikip things the definition of freezing is important.

Maybe. But so far, I haven't seen an agreed on reference experiment
that reliably shows the effect, that many other credible scientists
have been able to then reproduce and agree, verify that it is happening.
Have you?


Agreement on what
is freezing would be important to duplicate these earlier reports, but
it's not important otherwise. Whatever definition is used for hot water
should be used for cold water, Duh.

Agree, that's why I said maybe, above.



Of course if you leave the cold water running and don't run the hot
water until it freezes, the hot water will freeze first. No one is
talking about that. It certainly seems possible to me that when water
is heated it changes physically so that it then cools more quickly.

But what is hard to fathom is how such small changes could overcome
the fact that the hot water still has so much more energy to lose before
it can freeze. If we were talking about some special conditions, where
one is just a few degrees different, I could see that happening. But the
M effect is alleged to occur with a big temp difference, eg like that
between hot tap water and cold being talked about here.



That's a lot less strange than 1000 other things that happen on earth.
I've never been close enough to a bunch of water molecules to see what
happens.


But modern science pretty much has been to that level and way beyond.
The problem here, AFAIK, is that the proponents of the M effect don't
have a simple reference experiment, reproduceable, verifiable by the
scientific community to show that the effect is real. Certainly not
with water at 140F and 70F, in a beaker or similar, placed into a
0F, controlled freezing environment, that's for sure.

On Sat, 06 Dec 2014 06:50:06 -0500, Norminn
wrote:

On 12/5/2014 1:47 PM, TimR wrote:
On Friday, December 5, 2014 12:20:31 PM UTC-5, wrote:
On Fri, 5 Dec 2014 05:53:54 -0800 (PST), TimR
wrote:

On Thursday, December 4, 2014 5:12:54 PM UTC-5, micky wrote:
Take the same care with the hot water pipes you do with the cold. It
turns out hot water pipes can freeze sooner than cold water.


I'm familiar with the Mpemba effect, but didn't know it applied to water pipes. Is there evidence for this?
I doubt there is any solid evidence to back up this "old wive's
tale"

I'm a born skeptic, but this time there might be something to it. There are a lot of anectdotal reports from plumbers and homeowners who say their hot water pipes froze first.

The Mpemba effect is proven, there is no doubt about hot water freezing faster in certain circumstances. My question was whether those would include domestic water pipes.

There certainly is a suggestion they can.

There are several hypotheses for why. The hot water heater removes dissolved gases as well as minerals, causing the freezing point to be lower; the hot water pipes are not often used during the night whereas most people are up to the toilet or sink and run the cold water occasionally; the hot water has more temperature gradients within it and transfers heat better. Nobody is sure. I would certainly protect both sets of pipes during cold weather.

Or, add a recirculation pump. That ought to make you immune.


HW pipes freeze first because there is less water in them?
The only one of those that really makes sense to me is the hot water
doesn't get used as much - which has nothing to do with the
temperature of the water (hot or cold)

For years I listened to plumbers at work complain about hoses causing outdoor faucets to freeze.

They said the hose sucks the cold air up to the faucet and freezes it.

That never made any sense to me but we did have quite a few freezups in the housing units.

I eventually found out the occupants were leaving the faucet turned on and a sprayer on the end of the hose to stop the water. So I guess it made sense the water froze all the way up the hose to the faucet and beyond.

When I first worked in a plant a senior engineer pulled me aside and gave me some advice. He said always listen to the mechanics when they tell you what happened. They are on the scene first and they're good observers. When they start to tell you why it happened, stop listening and just pretend, tune them out quick. They are probably going to tell you something that is impossible by the laws of physics. You are at risk of ignoring what they really did see just because their explanation of why doesn't make sense.

On Sat, 6 Dec 2014 09:54:14 -0800 (PST), TimR
wrote:

For years I listened to plumbers at work complain about hoses causing outdoor faucets to freeze.

They said the hose sucks the cold air up to the faucet and freezes it.

That never made any sense to me but we did have quite a few freezups in the housing units.

I eventually found out the occupants were leaving the faucet turned on and a sprayer on the end of the hose to stop the water. So I guess it made sense the water froze all the way up the hose to the faucet and beyond.

When I first worked in a plant a senior engineer pulled me aside and gave me some advice. He said always listen to the mechanics when they tell you what happened. They are on the scene first and they're good observers. When they start to tell you why it happened, stop listening and just pretend, tune them out quick. They are probably going to tell you something that is impossible by the laws of physics. You are at risk of ignoring what they really did see just because their explanation of why doesn't make sense.
Frostproof "hydrants" self drain when shut off. Frostproof hose bibs
will drain if they are not installed on an upward slope. The actual
valve is at the inner end - generally in heated area like basement.
If a hose is left connected, water remains in the hosebib and they
WILL freeze - generally pulling the extension tube out of the faucet
which is in the heated area -and pulling the washer off the seat,
causing the water to try to flow - when the ice melts you have water
EVERYWHERE.

Don't ask how I know!!!!