Hello Everybody,
Merry Christmas from Pittsburgh, PA

It is getting cold here! And I just started a new job with a company that
does plumbing, heating, and cooling (I am not the plumber for I studied the
heating and cooling and refrigeration)

Big question!
When the outside temps cause the various inside pipes to freeze and there are
both hot and cold pipes that have similar exposure, is the hot pipe going to
freeze first?

Rettgerinc wrote:
Hello Everybody,
Merry Christmas from Pittsburgh, PA

It is getting cold here! And I just started a new job with a company that
does plumbing, heating, and cooling (I am not the plumber for I studied the
heating and cooling and refrigeration)

Big question!
When the outside temps cause the various inside pipes to freeze and there are
both hot and cold pipes that have similar exposure, is the hot pipe going to
freeze first?

If there are significant periods of time when water is not flowing
through the hot pipes, i.e. no "hot" faucets are opened and the system
does not use a circulating pump or a thermosyphon loop to provide
"quicker hot water", then there will be no difference in the freezing time.

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"As long as there are final exams, there will be prayer in public
schools"

Hello Everybody,
Merry Christmas from Pittsburgh, PA

It is getting cold here! And I just started a new job with a company that
does plumbing, heating, and cooling (I am not the plumber for I studied the
heating and cooling and refrigeration)

Big question!
When the outside temps cause the various inside pipes to freeze and there are
both hot and cold pipes that have similar exposure, is the hot pipe going to
freeze first?


Hmm...I don't know what the scientific answer is going to be but last
year we had a burst and *both* the hot *and* cold pipes split in almost
the same places (they were side by side). These pipes ran along an
outside wall and ran to the washer hook-up. We had only been living in
the house for 2 weeks when they burst and I didn't know where the shut
off valve was. Water was jetting up from the splits, hitting the roof
and coming down again like a waterfall! At first I thought it was the
upstairs neighbour who had the leak until I plunged under the waterfall
to discover the splits in both pipes.

I found the hot water shut off close to the hot water tank but the cold
water eluded me for a while and finally I had to call the landlord and
ask him where it was. It turned out to be located under a false 'floor'
in the bathroom 'cupboard'! By the time I got the cold water shut off we
had 2-3" of water on the floor.

So from my experience they can both go at the same time...lol.


--
Larry Green

http://math.ucr.edu/home/baez/physic...hot_water.html


"Rettgerinc" wrote in message
...
Hello Everybody,
Merry Christmas from Pittsburgh, PA

It is getting cold here! And I just started a new job with a company
that
does plumbing, heating, and cooling (I am not the plumber for I studied
the
heating and cooling and refrigeration)

Big question!
When the outside temps cause the various inside pipes to freeze and there
are
both hot and cold pipes that have similar exposure, is the hot pipe going
to
freeze first?

"Larry Green" wrote: (clip) the cold water eluded me for a while and
finally I had to call the landlord and ask him where it was. (clip)
^^^^^^^^^^^^^
And did the landlord take care of the repair, or were you stuck for it.

"Larry Green" wrote: (clip) the cold water eluded me for a while and
finally I had to call the landlord and ask him where it was. (clip)
^^^^^^^^^^^^^
And did the landlord take care of the repair, or were you stuck for it.



He was there within 5-10 minutes of my call along with his wife and both
are retirement age. He made the repairs *after* he and his wife helped
'bail out' the utility room using buckets, mops and snow shovels!
Thankfully the floor in there is about 3" lower than the rest of the
house so most of the water was contained to the floor of the one room.

My biggest concern was the 'waterfall' of water was spraying all over
the rather old electrical panels located directly above the breaks but
once the leak was stopped I checked the panels and they were bone
dry......PHEW!

It turns out the exhaust duct for the dryer only had a plastic shopping
bag stuffed in it and an icy wind had been 'funnelled' directly over the
pipes freezing them solid and splitting the copper pipes. Obviously the
water then burst through when they thawed. As we did not have a machine
hooked up at the time we never noticed they were frozen in the first place.

--
Larry Green

Pipes don't freeze. It's the water in them that does. If the water in both
pipes becomes stagnant then it will freeze if pipe temperature falls
significantly below freezing long enough. As to which water in which pipe
will freeze first and you're into splitting hairs, then I guess if the last
usage pattern was identical (both hot and cold water used simultaneously at
same pressure levels) then theoretically the water in the cold water pipe
should freeze first since it was originally at a lower temperature. I'm not
a plumber so something could be missing in my reply. What I do know is that
allowing just a trickle of water to flow in either pipe will prevent
freezing and many less fortunate take advantage of this since water bills
are lower than heating (gas, oil or electricity) bills.

"Rettgerinc" wrote in message
...
Hello Everybody,
Merry Christmas from Pittsburgh, PA

It is getting cold here! And I just started a new job with a company
that
does plumbing, heating, and cooling (I am not the plumber for I studied
the
heating and cooling and refrigeration)

Big question!
When the outside temps cause the various inside pipes to freeze and there
are
both hot and cold pipes that have similar exposure, is the hot pipe going
to
freeze first?

Yup.
The hot water heater reduces the dissolved minerals slightly, mainly
carbonates; enough to make a slight difference in the freezing point.
Bugs

I think that article gives an explanation as to why if ever the "hot water"
freezes faster. Yes, it's news to me but it's not categorically stating that
water in the "hot" pipes will always freeze faster.

"Bugs" wrote in message
ups.com...
Yup.
The hot water heater reduces the dissolved minerals slightly, mainly
carbonates; enough to make a slight difference in the freezing point.
Bugs

In article 5Hhzd.6464$h.4018@trnddc04, says...

Bill

I beleive you about your water freeze comparison. It surprized me. I
tried it with my water here at home. My results are much different than
yours.

I half filled two identical drinking glasses with water.and placed them in
the freezer. one glass had 60 degree water and the other had 80 degree
water. It took a little over an hour for the "cold tap filled" glass to
form crystals while the "warm water filled" was still without crystals. The
odd part was that both waters were at the same temperature after 1 hour and
15 minutes, yet the cold water filled was much more crystalized. Go
figure!!


Toying with us again, Jerry, or just trolling? g

Ned Simmons

"Ned Simmons" wrote in message
...
In article 5Hhzd.6464$h.4018@trnddc04, says...

Bill

I beleive you about your water freeze comparison. It surprized me. I
tried it with my water here at home. My results are much different than
yours.

I half filled two identical drinking glasses with water.and placed them
in
the freezer. one glass had 60 degree water and the other had 80 degree
water. It took a little over an hour for the "cold tap filled" glass to
form crystals while the "warm water filled" was still without crystals.
The
odd part was that both waters were at the same temperature after 1 hour
and
15 minutes, yet the cold water filled was much more crystalized. Go
figure!!


Toying with us again, Jerry, or just trolling? g

Ned

I must have been obscure with my explanation about testing the theory that
"hot water" will freeze more quickly than "cold water".
I assume the theory is correct, but only under special-limited conditions.

Tell me what I made obscure, or 'trolllike'.

Jerry

Ned Simmons

Ah, the old canard about hot water freezing before the cold water will!

Here's how the canard got started.
If you take some hot water and cold water and put them into the freezer, the
hot water will lose heat faster than the cold water will. This is indeed
true as the hot water has a lot higher temp differential than the colder
water will. As a result of this heat loss, the typical idiot will conclude
that the hot will freeze before the cold water will because it will be
losing heat faster than the cold water will. The reason he's an idiot is
that the hot water when it gets colder, will lose heat at the same rate that
the cold water was losing it. As a result, the hot water will always be
behind the cold water in getting to the freezing point.
The curve of heat loss isn't a linear slope but rather a curved slope
depending upon the instantenous temp differential between the water and the
air surrounding it.
I'll note that when playing this game in the freezer, you can make it turn
out differently depending upon how much of the glass is touching the cold
stuff inside and which glass it is. Touching some cold meat or such will
increase the transfer of heat out of the glass and that will drastically
affect the actual point at which the freezing begins.
--
Why isn't there an Ozone Hole at the NORTH Pole?

"Bob May" wrote: (clip) As a result of this heat loss, the typical idiot
will conclude that the hot will freeze before the cold water will because it
will be losing heat faster than the cold water will. (clip)
^^^^^^^^^^^^^^^^
But how would an idiot know how fast the water is losing heat?

I suppose the same idiot will conclude that a car will coast farther from 30
MPH than from 60 MPH. I met that guy once. He was low on gas, so he drove
really fast, so he would get home before he ran out. G

On Sat, 25 Dec 2004 22:45:24 GMT, "Leo Lichtman"
wrote:


"Bob May" wrote: (clip) As a result of this heat loss, the typical idiot
will conclude that the hot will freeze before the cold water will because it
will be losing heat faster than the cold water will. (clip)
^^^^^^^^^^^^^^^^
But how would an idiot know how fast the water is losing heat?

I suppose the same idiot will conclude that a car will coast farther from 30
MPH than from 60 MPH. I met that guy once. He was low on gas, so he drove
really fast, so he would get home before he ran out. G

I knew a milk driver that did that because his brakes were bad and he
had to hurry home to fix them...
Garry

PS
I have heard of hot water freezing so fast the ice was still hot...

In article i9kzd.5978$1U6.1462@trnddc09, says...

"Ned Simmons" wrote in message
...
In article 5Hhzd.6464$h.4018@trnddc04, says...



I half filled two identical drinking glasses with water.and placed them
in
the freezer. one glass had 60 degree water and the other had 80 degree
water. It took a little over an hour for the "cold tap filled" glass to
form crystals while the "warm water filled" was still without crystals.
The
odd part was that both waters were at the same temperature after 1 hour
and
15 minutes, yet the cold water filled was much more crystalized. Go
figure!!


Toying with us again, Jerry, or just trolling? g

Ned

I must have been obscure with my explanation about testing the theory that
"hot water" will freeze more quickly than "cold water".
I assume the theory is correct, but only under special-limited conditions.

Tell me what I made obscure, or 'trolllike'.

Jerry


I got the feeling you were being coy about the reason the two glasses
were stuck at the same temperature -- the large heat of fusion of water.
Was I mistaken?

Ned Simmons

"Ned Simmons" wrote in message
...
In article i9kzd.5978$1U6.1462@trnddc09, says...

"Ned Simmons" wrote in message
...
In article 5Hhzd.6464$h.4018@trnddc04, says...



I half filled two identical drinking glasses with water.and placed
them
in
the freezer. one glass had 60 degree water and the other had 80 degree
water. It took a little over an hour for the "cold tap filled" glass
to
form crystals while the "warm water filled" was still without
crystals.
The
odd part was that both waters were at the same temperature after 1
hour
and
15 minutes, yet the cold water filled was much more crystalized. Go
figure!!


Toying with us again, Jerry, or just trolling? g

Ned

I must have been obscure with my explanation about testing the theory
that
"hot water" will freeze more quickly than "cold water".
I assume the theory is correct, but only under special-limited
conditions.

Tell me what I made obscure, or 'trolllike'.

Jerry


I got the feeling you were being coy about the reason the two glasses
were stuck at the same temperature -- the large heat of fusion of water.
Was I mistaken?

Ned

I was real doubtfull that warm water from the hot water tap would freeze
before cooler water taken from the cold water tap, so I tested it. I
began the test with one glass at 60 degrees and the other at 80 degrees.
It took about an hour and a quarter for the 1/2 full 'glass of water'
began to develop crystals. Both glasses were placed close together and in
the same environment. I measured the water temperature at about every 15
minutes. As you'd expect, the water from the warm water tap was always
warmer than the water from the cold water tap. But after about an hour the
difference between the two temperatures was undetectable with my
thermometer. But crystals did form in the glass that had been filled from
the cold water tap.

I wouldnt br surprized to,learn that there is a chemical difference in the
two waters. Something probably boils out of the water in the hot water
heater.

It actually surprized me that *my* water freezed the water from the cold
water tap first. I suspect Bill's water from the warm water tap has had
changed in some way thats different from the change in *my* water.

I have heard about this "Hot water freezes before cold water" in 1949 when
I was in the USAF, in Alaska. I never could accept the validity of that
statement. But I do know that there are conditions where the convection
currents within the hot water container serve to distribute the temperature.
And, it might be that the hot water had some gasses boiled out thereby
providing a better condition for freezing.
I had always thought the "hot water freezes quicker" was restricted to
special labroatory experiments, till Bill said he freezes warm water more
quickly than cooler water in his "refrigerator freezer". So, I tried it
today. I dont know any more now than when I started.

Jerry

On 25 Dec 2004 06:05:22 GMT, Ignoramus10474
wrote:

a hot pipe never freezes.

Technically you may be right - but the hot water pipe, when it cools
down, most definitely does.
And what a mess it makes when it does!!!!
The heaters in my brother's shop went out one extremely cold winter
weekend. The water pipes, back then, were strapped directly to the
concrete block wall (they are now strapped out about 2 inches) and
when the pipes froze and split a SMALL amount of water worked it's way
down the pipes. The water heater was only a matter of a few feet away
- and as soon as SOME water started to move, hot water got to the
split and soon there was a spray of VERY hot water shooting in all
directions - little more than a geiser of wet steam - which froze in a
veil over EVERYTHING.
I think it was breaking ice setting off the alarm that caught his
attention.

i

On 25 Dec 2004 02:02:35 GMT, Rettgerinc wrote:
Hello Everybody,
Merry Christmas from Pittsburgh, PA

It is getting cold here! And I just started a new job with a company that
does plumbing, heating, and cooling (I am not the plumber for I studied the
heating and cooling and refrigeration)

Big question!
When the outside temps cause the various inside pipes to freeze and there are
both hot and cold pipes that have similar exposure, is the hot pipe going to
freeze first?

In article 0wrzd.3958$Y57.2782@trnddc08, says...

I have heard about this "Hot water freezes before cold water" in 1949 when
I was in the USAF, in Alaska. I never could accept the validity of that
statement. But I do know that there are conditions where the convection
currents within the hot water container serve to distribute the temperature.
And, it might be that the hot water had some gasses boiled out thereby
providing a better condition for freezing.

Another explanation that seemed to work in my freezer a few years ago.

I put a glass of hot water and a glass of cold water on my freezer
shelf, and the hot water froze first. When I put the glasses on the
plastic bottom shelf, the cold water froze first.

If your freezer's cooling coils are built into the shelf, and if you
have't defrosted the freezer recently, then the cooling coils will be
isulated with a good layer of frost. A glass full of hot water will
melt through more of this layer of isulation, so the coil will cool it
faster.

--
is Joshua Putnam
http://www.phred.org/~josh/
Braze your own bicycle frames. See
http://www.phred.org/~josh/build/build.html

I had always thought the "hot water freezes quicker" was restricted to
special labroatory experiments, till Bill said he freezes warm water more
quickly than cooler water in his "refrigerator freezer". So, I tried it
today. I dont know any more now than when I started.

Jerry
Jery I found this to happen when I fill my bicycle water bottle with hot
water and went on a bicycle ride in sub freezing weather. I assume that the
cold air moving over the bottle has an effect. My origianal post is below.
As a bicycle riders who has filled my water bottle with water from the hot
water tap, I found that the bottle fill with warm water freezes before the
bottle filled from the cold water tap.
--
www.billcotton.com
N40° 3.744' W75° 6.180'

Interesting link there, kklein! I'm surprised more posters
have not
paid more attention to the phenomena of supercooling! That
is
more interesting to me. I have seen this _many_ times in my
sauna,
a separate building out back, in the water pails. The temp
can go
down into the upper twenties and the water in the pails is
not frozen
but all it takes is the slightest movement and the water
crystallizes
completely to the bottom! When it's cold I'll check the
pails to see
if they are ice and if not I'll swirl the bucket with a
kauhaa and within
minutes it is possible to invert the pail leaving a block of
solid ice on
the bench! The thing is the water must cool very slowly and
in total
calm conditions, even vibrations will trigger the freezing.
I've been
told that even dropping in a single grain of sand is enough
to do it
but I haven't tried that yet.
Phil Kangas
N 46 d 53.045'
W 88 d 51.717'

"kklein" wrote in message
http://math.ucr.edu/home/baez/physic...hot_water.html


"Rettgerinc" wrote in message
Hello Everybody,
Merry Christmas from Pittsburgh, PA

It is getting cold here! And I just started a new job
with a company
that
does plumbing, heating, and cooling (I am not the
plumber for I studied
the
heating and cooling and refrigeration)

Big question!
When the outside temps cause the various inside pipes
to freeze and there
are
both hot and cold pipes that have similar exposure, is
the hot pipe going
to
freeze first?

Bill, does that put you on the West side of Rolling Green??

I have thought about that "freezing of water for over 55 years and never
took time to test it. Then, when I tried several days ago, I realized how
difficult it is to control all parameters in a test like this. I might have
been better off if I'd not tried to test the theory.

Jerry


"Bill Cotton" wrote in message
...
I had always thought the "hot water freezes quicker" was restricted to
special labroatory experiments, till Bill said he freezes warm water more
quickly than cooler water in his "refrigerator freezer". So, I tried it
today. I dont know any more now than when I started.

Jerry
Jery I found this to happen when I fill my bicycle water bottle with hot
water and went on a bicycle ride in sub freezing weather. I assume that
the
cold air moving over the bottle has an effect. My origianal post is below.
As a bicycle riders who has filled my water bottle with water from the
hot
water tap, I found that the bottle fill with warm water freezes before
the
bottle filled from the cold water tap.
--
www.billcotton.com
N40° 3.744' W75° 6.180'

"Jerry Martes" wrote in message
news:STLzd.8454$hc7.8310@trnddc06...
Bill, does that put you on the West side of Rolling Green??
East side, but the coordinates are from Topo USA, I haven't check with the
gps since SA was removed.
--
www.billcotton.com
N40° 3.744' W75° 6.180'

Bill
I used Street USA. I cant get this computer to accept my Topo USA
My lap top accepts both *and* both hook up with the Earthmate GPS.
Jerry



"Bill Cotton" wrote in message
...


"Jerry Martes" wrote in message
news:STLzd.8454$hc7.8310@trnddc06...
Bill, does that put you on the West side of Rolling Green??
East side, but the coordinates are from Topo USA, I haven't check with the
gps since SA was removed.
--
www.billcotton.com
N40° 3.744' W75° 6.180'

I don't know about the physics but I was once in the property management
business. When we had a really hard freeze down here the company got
several hundred broken pipe calls. 80% of them are on the hot water side.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Rettgerinc" wrote in message
...
Hello Everybody,
Merry Christmas from Pittsburgh, PA

It is getting cold here! And I just started a new job with a company
that
does plumbing, heating, and cooling (I am not the plumber for I studied
the
heating and cooling and refrigeration)

Big question!
When the outside temps cause the various inside pipes to freeze and there
are
both hot and cold pipes that have similar exposure, is the hot pipe going
to
freeze first?

There the hot water pipes are more eroded than the cold water ones are as
the heat assists in the corrosion of the pipe material. It ain't that the
hot water froze first but rather that the pipes just weren't strong enough
to withstand the forces on the pipe from the ice.

--
Why isn't there an Ozone Hole at the NORTH Pole?

In article ,
Bob May wrote:
Ah, the old canard about hot water freezing before the cold water will!

Here's how the canard got started.
If you take some hot water and cold water and put them into the freezer, the
hot water will lose heat faster than the cold water will. This is indeed
true as the hot water has a lot higher temp differential than the colder
water will. As a result of this heat loss, the typical idiot will conclude
that the hot will freeze before the cold water will because it will be
losing heat faster than the cold water will. The reason he's an idiot is
that the hot water when it gets colder, will lose heat at the same rate that
the cold water was losing it. As a result, the hot water will always be
behind the cold water in getting to the freezing point.
The curve of heat loss isn't a linear slope but rather a curved slope
depending upon the instantenous temp differential between the water and the
air surrounding it.
I'll note that when playing this game in the freezer, you can make it turn
out differently depending upon how much of the glass is touching the cold
stuff inside and which glass it is. Touching some cold meat or such will
increase the transfer of heat out of the glass and that will drastically
affect the actual point at which the freezing begins.
--
Why isn't there an Ozone Hole at the NORTH Pole?



The one thing that no one has mentioned yet here is mass transfer.

The hot water will loose heat faster at first, until it reaches the same
temperature as the cold water, at which point they cool at the same rate.
This implies that they should either freeze together or the cold water
should win (depends on starting temperatures, surface areas, etc.)

This assumes that all other things are equal... and they never are...

If the containers are open (like an ice cube tray) the hot water is
evaporating off much faster than the cold water. It is loosing mass and with
it energy. Once it reaches the same temperature as the cold sample the
formerly hot sample now has less mass than the cold sample and will cool
faster.

Try the experiment again with a cover over the containers.

Of course, the next post I read will say the same thing...

-- Joe

--
Joseph M. Krzeszewski Mechanical Engineering and stuff
Jack of All Trades, Master of None... Yet