Buried water pipes freeze-has been cold-the sun comes out

In summary, the conversation discusses a phenomenon where buried water lines suddenly freeze solid after a few days of cold weather and the sun comes out. Contractors believe that the heat from the sun drives the cold down, causing the pipes to freeze. However, this idea is questioned by others who suggest that the pipes may have just coincidentally frozen at the same time. The conversation also touches on the questionable validity of websites as sources of scientific information and the effects of urban myths and common practices in the industry.
  • #1
WVBrady
3
0
Hi: I am a EE, but I have a question that I have searched for on the Internet and not found an answer. Contractors tell me that when it has been cold for several days and the sun comes out, that buried water lines that have not frozen all winter will suddenly freeze solid. It must be a real phenomenon, because they all have the same description: "The heat drives the cold down". I would like to know if anyone has a reason that is based on the laws of physics.

I have asked on another forum where there are some smart guys of various technical backgrounds, but they don't believe it. Most of them also don't believe that warm water can freeze before cold water, even after I posted to link that claims to verify it (known as the Mpemba effect".

http://www.businessinsider.com/a-new-theory-explains-why-warm-water-freezes-faster-than-cold-2013-11

Any ideas?
 
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  • #2
Welcome to PF!

No, the heat does not drive the cold down. What probably happens is that the cold continues to travel down for a little while after the sun comes out.
 
  • #3
WVBrady said:
Hi: I am a EE, but I have a question that I have searched for on the Internet and not found an answer. Contractors tell me that when it has been cold for several days and the sun comes out, that buried water lines that have not frozen all winter will suddenly freeze solid. It must be a real phenomenon, because they all have the same description: "The heat drives the cold down". I would like to know if anyone has a reason that is based on the laws of physics.

I have asked on another forum where there are some smart guys of various technical backgrounds, but they don't believe it. Most of them also don't believe that warm water can freeze before cold water, even after I posted to link that claims to verify it (known as the Mpemba effect".

http://www.businessinsider.com/a-new-theory-explains-why-warm-water-freezes-faster-than-cold-2013-11

Any ideas?

Yes. You shouldn't expect to get valid scientific theories from a website called businessinsider.com. :frown:

It can take several days for the temperature below ground to change in response to changes in the ambient temperature. After all, Earth does have some insulating effect. It was probably coincidental that the buried water pipes froze just as the weather turned sunny. :wink:
 
  • #4
SteamKing said:
Yes. You shouldn't expect to get valid scientific theories from a website called businessinsider.com. :frown:

It can take several days for the temperature below ground to change in response to changes in the ambient temperature. After all, Earth does have some insulating effect. It was probably coincidental that the buried water pipes froze just as the weather turned sunny. :wink:
Maybe you would like this reference better: http://arxiv.org/abs/1310.6514

Also, it wasn't just a one-time occurrence; it was common knowledge among contractors, as was the other effect referenced above.
 
  • #5
WVBrady said:
Hi: I am a EE, but I have a question that I have searched for on the Internet and not found an answer. Contractors tell me that when it has been cold for several days and the sun comes out, that buried water lines that have not frozen all winter will suddenly freeze solid. It must be a real phenomenon, because they all have the same description: "The heat drives the cold down". I would like to know if anyone has a reason that is based on the laws of physics.

I have asked on another forum where there are some smart guys of various technical backgrounds, but they don't believe it. Most of them also don't believe that warm water can freeze before cold water, even after I posted to link that claims to verify it (known as the Mpemba effect".

http://www.businessinsider.com/a-new-theory-explains-why-warm-water-freezes-faster-than-cold-2013-11

Any ideas?
What is the symptom of the "pipes freezing solid." Is it (a) that the pipes burst or (b) that no water flows through them any more?

Chet
 
  • #6
WVBrady said:
Maybe you would like this reference better: http://arxiv.org/abs/1310.6514

Also, it wasn't just a one-time occurrence; it was common knowledge among contractors, as was the other effect referenced above.
That's a sperate issue to the OP. If the pipes froze earlier in the winter after a warmer summer it might apply. Warming the Earth above a pipe will raise the temperature of that pipe, there's no two ways about it.
I'd guess urban myth along with coincidence. Unless flow rate has some correlation to the sun in which case flow would drop enough for the pipe to freeze..
 
  • #7
WVBrady said:
Contractors tell me that when it has been cold for several days and the sun comes out, that buried water lines that have not frozen all winter will suddenly freeze solid

You have to explain what pipes the contractors are talking about. Common practice would be to bury the pipes below the frost line, where the soil never freezes. A cold snap will drive the frost line farther down, sometimes overlapping the pipes.
http://en.wikipedia.org/wiki/Frost_line
 
  • #8
Chestermiller said:
What is the symptom of the "pipes freezing solid." Is it (a) that the pipes burst or (b) that no water flows through them any more?

Chet
I'm not sure.
 
  • #9
WVBrady said:
common knowledge among contractors
Big red flag.
256bits said:
Common practice would be to bury the pipes below the frost line, where the soil never freezes.
Properly backfilled, this is great. "Common practice of 'Industry standards' " is not so great. Snow melt soaking into loose backfill and freezing raises thermal conductivity of "soil" over pipes and you ARE in trouble.
 
  • #10
Bystander said:
"Common practice of 'Industry standards' " is not so great.
I was a little hesitant to put it down that way, which is why I asked the question about the contractors and their pipes, but I wanted to get the frost line out there. Loose granular fill, instead of a more clayish fill might be standard in that area. With salted roads, and that leaking down spells more trouble.
 
  • #11
There is also the complexity that when things start to warm, pipes on the surface thaw and water starts to flow again. A layer of ice on the inside of a pipe may break away in warming weather and become mobile. That mobile ice may move into places where it can plug the flow for some time.
 

1. Can buried water pipes freeze?

Yes, it is possible for buried water pipes to freeze if the temperature drops below freezing and the pipes are not properly insulated.

2. How cold does it have to be for buried water pipes to freeze?

The temperature typically needs to drop below 32°F (0°C) for buried water pipes to freeze, but this can vary depending on factors such as insulation and depth of the pipes.

3. What can I do to prevent my buried water pipes from freezing?

To prevent your buried water pipes from freezing, you can insulate them with foam or other materials, install heat tapes, and keep the water running at a slow drip during freezing temperatures.

4. What should I do if my buried water pipes freeze?

If your buried water pipes freeze, you should shut off the water supply and call a plumber to thaw the pipes and assess for any potential damage. Do not try to thaw the pipes yourself as this can cause further damage.

5. Will the sun coming out after a cold spell thaw my buried water pipes?

No, the sun coming out after a cold spell is not enough to thaw frozen buried water pipes. You will likely need to use a heat source or call a professional plumber to thaw the pipes. It is important to take preventive measures to avoid frozen pipes in the first place.

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