S Davis

Western WA

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Lantley wrote: S Davis wrote: Wadcutter wrote: Lantley wrote: wa8yxm wrote: J&R wrote: Hot water will freeze before cold water.
That is a myth
It's not a myth. It's basic high school chemistry
Then you slept thru your high school chemistry class.
Still water freezes at 32 deg F. Remember that from your high school chemistry. So what it takes to freeze water is to drop the temp from its existing temp to 32 deg. That requires a transfer of heat away from the water. If the beginning temp of the water is 60 deg then it requires a transfer of 28 deg to drop the water to freezing. If the water is 200 deg then it requires a transfer of 168 deg. That is simple high school chemistry.
You flunked your class. Stay after school. Re-read the chapter on heat transfer. Do some extra credit work and maybe you'll pass chemistry this semester.
So what happens if there is less water, does it freeze faster?
I won't even bother to explain why hot water freezes faster because I don't think you would understand anyway. The idea that hot water freezes faster is a known phenomenon. It's not an idea that just came along within this thread.
Aw come on my small brain might grasp it if you talk slow. A smaller mass will lose heat quicker and freeze faster as it will have less stored energy than a larger mass. I have seen and learned a lot in 32 years in plumbing and hydronic heating, most of the time hot water lines freeze faster and first. I have thawed and fixed hundreds of frozen pipe jobs so that is real world experience.
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Wadcutter

IL

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Lantley wrote:
I won't even bother to explain why hot water freezes faster because I don't think you would understand anyway. The idea that hot water freezes faster is a known phenomenon. It's not an idea that just came along within this thread.
It's called the Mpemba Effect. It's actually not a proven, verified experiment. If you had actually studied chemistry then you would know that.
It was a theory postulated by a 13 year old school boy in Tanzania. He witnessed an ice cream mix frost over on the top and then went on to postulate that the mix had frozen quicker than cold mix. He did not understand what he was seeing and his conclusion was based on things he didn't understand.
In controlled experiments the Mpemba Effect hasn't been replicated. All the 13 year old boy saw was a frosting of the surface and he then jumped to the conclusion, erroneously, that the mix had frozen. It had not. It was frost he had witnessed, not freezing of the mix. His theory has not been verified in controlled experiments since 1963.
But this myth keeps getting repeated by those who have no knowledge of science. It's something they read on the internet and repeat it not understanding what it is.
There - that's the simple explanation that is not complicated so you can understand what you think you know.
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Lantley

Ellicott City, Maryland

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S Davis wrote: Lantley wrote: S Davis wrote: Wadcutter wrote: Lantley wrote: wa8yxm wrote: J&R wrote: Hot water will freeze before cold water.
That is a myth
It's not a myth. It's basic high school chemistry
Then you slept thru your high school chemistry class.
Still water freezes at 32 deg F. Remember that from your high school chemistry. So what it takes to freeze water is to drop the temp from its existing temp to 32 deg. That requires a transfer of heat away from the water. If the beginning temp of the water is 60 deg then it requires a transfer of 28 deg to drop the water to freezing. If the water is 200 deg then it requires a transfer of 168 deg. That is simple high school chemistry.
You flunked your class. Stay after school. Re-read the chapter on heat transfer. Do some extra credit work and maybe you'll pass chemistry this semester.
So what happens if there is less water, does it freeze faster?
I won't even bother to explain why hot water freezes faster because I don't think you would understand anyway. The idea that hot water freezes faster is a known phenomenon. It's not an idea that just came along within this thread.
Aw come on my small brain might grasp it if you talk slow. A smaller mass will lose heat quicker and freeze faster as it will have less stored energy than a larger mass. I have seen and learned a lot in 32 years in plumbing and hydronic heating, most of the time hot water lines freeze faster and first. I have thawed and fixed hundreds of frozen pipe jobs so that is real world experience.
Lets just start with the premise that if you wanted to due a test/comparison you would start with equal amounts of the substance in question.
I'm not sure if you are agreeing or dis agreeing. But yes I believe hot water will freeze before the cold does.
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GDS-3950BH

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LOL.......Bored are we? Maybe go help the guy in that other thread get the stripped screw out of his 10 yr old laptop, or perhaps argue over how many inch pounds it was torqued to by Hewlett Packard and what the temperature was at the time in the factory?
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wa8yxm

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Regarding a smaller mass will lose heat quicker. That is the false item
A smaller SURFACE area will lose heat slower
That's why i said like a cup of water v/s a 5 gallon pail
The ratio of mass to surface area is what determines how fast the large/small mass freezes for at any given temperature of water and air the water will loose heat at the same rate PER SQUARE INCH OF SURFACE AREA .
Put that same cup of water in a narrow neck vacuum container (Thermous) and it will take a lONG time to freeze for there is very little exposed surface.
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noteven

Turtle Island

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Do any of youse hot vs cold freezing experts know why a frozen water line gives me a pain in my ass?
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StirCrazy

Kamloops, BC, Canada

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noteven wrote: Do any of youse hot vs cold freezing experts know why a frozen water line gives me a pain in my ass?
was your hotwater heater running all night? if it wasn't then I could see the water in the tank freezing. can you turn your bypass valve for winterizing? that will let youi know if it is a localized issue to the hotwater heater or the rest of the plumbing.
for the other guys arguing about weather hot water will freeze faster or not....
the same volume of cold and hot water exposed to the same input of heat the cold water will freeze faster. in some circomstances it can be made to freese faster though, this is the principle used in a skating wring where most of the colling is on the bottom of the water surface this allows the top to remain hot and hot water will evaporate faster than cold water, so as the bottom is freezing the surface is evaporation making it seam like it is freezing faster. but let me introduce a new wrinkle to this, if you put deoxygenated water in the mix it will freeze even faster. this is why NHL hocky rinks use deoxygenated hot water, plus it freezes clear and the lines show up better.
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time2roll

Southern California

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noteven wrote: Do any of youse hot vs cold freezing experts know why a frozen water line gives me a pain in my ass? I use a circulating pump on the hot water line. Pump is activated when the furnace is cycled on or with a manual switch.
Heated water does not freeze.
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wing_zealot

East of the Mississippi

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noteven wrote: Do any of youse hot vs cold freezing experts know why a frozen water line gives me a pain in my ass? I'm m not sure why, did you sit on it?
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