OT - frozen pipes

[Dekonick]

My last few shifts at work I have seen many frozen and broken water pipes. The north east states are having some unusually cold weather and I thought I would pass this on to help prevent anyone from having similar issues. The killer is the wind as a cold wind on an exterior wall can be enough to freeze what otherwise would be well insulated pipes. The key is to keep the water moving. Make sure you have turned off any outside spigots and drained them. If you have a fire sprinkler system in your house, make sure the pipes in the attic have insulation covering them. It is a good idea to have some extra insulation blown into your attic anyway as it will save you $$ in the long run. Many of the broken pipes I have seen lately have had just a small section of insulation missing, or not enough covering them. Find the longest run of pipe you have and have that faucet/spigot drip - the dripping should be enough to prevent freezing.

OK - so what if you go to take a shower and no water comes out? Should you get a hair dryer and heat the pipes??? BE CAREFUL! This can cause steam buildup and burst the pipe. So what do you do? Open the faucets, and run water. Warm the area around the pipes (NO DIRECT HEAT!) It may take some time but eventually it will start to drip, then run. GO CHECK and look for water leaking where the pipe runs!

OK enough - just try'n to save everyone some headaches and $$$

Dek.

The

[Volant]

Thank you for the advice. :)

[wc1934]

Do you happen to know which freezes first - the hot water pipe or the cold, or do they freeze at the same rate?

[hookookadoo]

Very helpful. I am in North Carolina but we are still seeing temps in the 20s consistently at night these days. One a second or more?

[Peter P.]

Another tip; some people wrap an electrical device around certain pipes which heats the pipe and prevents freezing.

One local residence recently suffered a catastrophic fire due to a malfunctioning pipe heater. So read and follow the directions closely, and inspect your pipe heating devices at least once a season.

[veggieburger]

If it's in a high risk area, run hot-air duct work to/past the pipes, and be sure to insulate. For egs, any pipes that run through an unfinished basement should DEFINITELY be insulated, at the very least.

[regularguy412]

Do you happen to know which freezes first - the hot water pipe or the cold, or do they freeze at the same rate?

In my experience, the hot seems to always freeze first. Mebbe it's because the hot water is less dense, so it takes less to freeze it. Hopefully, the engineers on the forum can lend some insight.

Mike in AR:beer:

[Louis]

Mebbe it's because the hot water is less dense

More seriously, it's really neat how the blip in water density at 4* C is so important out in the environment, where it results in lakes "turning over" as the surface temp changes.

Temp (°C) Density (kg/m3)
+100 958.4
+80 971.8
+60 983.2
+40 992.2
+30 995.6502
+25 997.0479
+22 997.7735
+20 998.2071
+15 999.1026
+10 999.7026
+4 999.9720
0 999.8395
−10 998.117
−20 993.547
−30 983.854

[chuckroast]

One more thing, and probably you know this anyway.....

Be sure to disconnect the hoses from any of your outside hose bibs/ spigots.

[Louis]

One more thing, and probably you know this anyway.....

Be sure to disconnect the hoses from any of your outside hose bibs/ spigots.

I also use those hose-bib covers to try to minimize the temp loss in the pipe inside the house. Depending on the location of the valve itself it can still get pretty cold where the water itself is, even if the spigot is off.

[rnhood]

Hot water generally freezes faster since it is less dense and, there is a greater temperature differential thus greater energy transfer rate. However, this assumes there is no thermal conductivity path to a warm or hot water source.

On a hockey rink, after the warm water is squeegeed on the ice by the Zamboni, there is no thermal path to a warm or hot water source so it quickly freezes. At home in the refrigerator, your ice maker water supply valve automatically cuts the flow of water off once the ice binge is full of water - so it freezes quickly.

This is not the case with a hot water pipe in a house though. There is a maintained conductivity path and that is the water column in the pipe going back to the hot water heater. The longer the path, the less the thermal conduction (more thermal resistance) but, the conduction path is there to some extent. Whether it freezes quicker than the cold water pipe is dependent on the variables associated with this column of water (water temp, cross sectional area of the water column and its length). My guess is that in the case of water pipes at home, the cold water pipe ends up freezing first.

[Lifelover]

In my experience, the hot seems to always freeze first. Mebbe it's because the hot water is less dense, so it takes less to freeze it. Hopefully, the engineers on the forum can lend some insight.

Mike in AR:beer:


I'm a engineer but you don't need to be one to figure it out. This is a classic question that is always over analyzed.

Hot water has to become cold water before it freezes. Thus, all other things equal, cold water will ALWAYS freeze faster.

If it is true that hot water pipes freeze more in homes, it is simply because they are not insulated as well. Nothing more scientific than that.

[gasman]

I'm a engineer but you don't need to be one to figure it out. This is a classic question that is always over analyzed.

Hot water has to become cold water before it freezes. Thus, all other things equal, cold water will ALWAYS freeze faster.
If it is true that hot water pipes freeze more in homes, it is simply because they are not insulated as well. Nothing more scientific than that.


Exactly !!!

Dek-Good words of wisdom

[Louis]

This is a classic question that is always over analyzed.

The premise was so silly I assumed the whole thing was in jest.

[Dekonick]

One more little pearl...

READ your insurance policy - I can almost guarantee that it will have a broken water pipe clause hidden somewhere... so if one breaks, you will foot the bill. Let me tell you that water damage can be significant.

[Louis]

Here's another good one: Zeno's Paradox of the Tortiose and Achilles

http://www.mathacademy.com/pr/prime/articles/zeno_tort/index.asp

"Zeno of Elea (circa 450 b.c.) is credited with creating several famous paradoxes, but by far the best known is the paradox of the Tortoise and Achilles. (Achilles was the great Greek hero of Homer's The Iliad.) It has inspired many writers and thinkers through the ages, notably Lewis Carroll and Douglas Hofstadter, who also wrote dialogues involving the Tortoise and Achilles.

The original goes something like this:

The Tortoise challenged Achilles to a race, claiming that he would win as long as Achilles gave him a small head start. Achilles laughed at this, for of course he was a mighty warrior and swift of foot, whereas the Tortoise was heavy and slow.

“How big a head start do you need?” he asked the Tortoise with a smile. “Ten meters,” the latter replied. Achilles laughed louder than ever. “You will surely lose, my friend, in that case,” he told the Tortoise, “but let us race, if you wish it.” “On the contrary,” said the Tortoise, “I will win, and I can prove it to you by a simple argument.” “Go on then,” Achilles replied, with less confidence than he felt before. He knew he was the superior athlete, but he also knew the Tortoise had the sharper wits, and he had lost many a bewildering argument with him before this.

“Suppose,” began the Tortoise, “that you give me a 10-meter head start. Would you say that you could cover that 10 meters between us very quickly?” “Very quickly,” Achilles affirmed. “And in that time, how far should I have gone, do you think?” “Perhaps a meter – no more,” said Achilles after a moment's thought. “Very well,” replied the Tortoise, “so now there is a meter between us. And you would catch up that distance very quickly?” “Very quickly indeed!” “And yet, in that time I shall have gone a little way farther, so that now you must catch that distance up, yes?”

“Ye-es,” said Achilles slowly. “And while you are doing so, I shall have gone a little way farther, so that you must then catch up the new distance,” the Tortoise continued smoothly. Achilles said nothing. “And so you see, in each moment you must be catching up the distance between us, and yet I – at the same time – will be adding a new distance, however small, for you to catch up again.” “Indeed, it must be so,” said Achilles wearily.
“And so you can never catch up,” the Tortoise concluded sympathetically.
“You are right, as always,” said Achilles sadly – and conceded the race.