Frozen pipes. ..

[countryguy]

I remember in my grade 13 Physics class, the teacher asked if hot or cold water froze quicker. When a student yelled out hot, the teacher almost took a hissy fit and whipped his rubber hose at the student LOL I remember him saying that the hot water has to cool down to below the freezing point so how can it possibly freeze quicker than cold water?

Gary

 

[iheartmaytag]

Did I miss that day of physics class?

Must have.
Hot flows to cold at a faster rate that cold/cold.

Cold water will boil faster too because it will absorb the heat transfer more quickly.

http://https//medium.com/the-physics-arxiv-blog/d8a2f611e853

 

[jeffg]

Kevin, heat tape is good in cases like yours, where the problem is limited to one pipe.

One can easily be made with regular 15-amp outdoor extension cord and oversized pipe insulation. Wrap the cord around the pipe, secure with ties or duct tape, put the insulation on and plug any 10-amp load into the cord. As mentioned a timer or thermostat can be attached if you want it automatic.

 

[davey7]

Rooftop pipes

My building has heat tape on our rooftop water supply pipes wrapped in heat tape and insulation. My neighbor turns the heat time on around the end of October. No frozen pipes as yet.

And yes, we have rooftop supply lines in Chicago.... (they were originally embedded in concrete)

 

[westie2]

On our farm growing up we had a big Forney welder that dad would hook up to thaw pipes it worked good. Used it for our underground pipe from the well to the barn and on to the house.

One of my grand mothers had her kitchen pipes freeze every winter and she would use an electric iron set on medium heat up against the pipe to thaw it. Work good.

 

[wayupnorth]

I used to live in a very old house and every time it would go sub zero the kitchen pipes froze to the sink. Problem was the pipes were on an inside wall in the middle of the kitchen. A hairdryer would get them thawed quickly but I never could figure how the cold was getting to an inside wall when bathroom pipes in an outside wall never caused a problem.

 

[wayupnorth]

Thawing frozen pipes

The local News tonight had a lead in with 2 places that had bad fires because some idiots used some sort of open flame when they had frozen pipes, probably a blow torch. I always used a hairdryer and it worked a little slower, but safer. One of my neighbors does damage restoration after frozen pipes, fires, and he said this winter has been absolutely nuts. We have been below zero more days this month than barely being above.

 

[NYCWriter]

WOW Kevin ...

... that is EXACTLY the same stove my Mom has.

Same color, too.

She's looking to replace it as part of a kitchen renovation. I'm trying to talk her out of it. That sucker has cooked HUNDREDS of meals, baked thousands of batches of cookies, cakes, brownies, etc. since she bought it in 1983, and has shown no signs of slowing down.

 

[vintagekitchen]

Don't let her Matt! !

It's a great stove, and nothing made today is going to be nearly as well built, last half as long, or be so easy to repair. The tappan will accept a standard calrod unit, standard infinite heat burner control, and most basic oven controls, all available SUPER CHEAP at the local hardware store or appliance parts house.

These new stoves all have electronic controls, even if it looks like a standard knob, behind it is an electronic control. Should one of those beasts stop working, the replacement part can be nearly as costly if not just as costly as replacing the stove. And they do fail. Especially on self cleaning models, since the high heat of the cleaning cycle leads to early failure in the control boards. When my grandmothers stove which cost 300 dollars suffered control board failure, the replacement board was going to cost 200 dollars.

 

[toploader1984]

Prevents frozen pipes

I found this one, it recirculates hot water into the cold lines bsck to the water heater when the valve senses cold water, it keeps water moving so pipes never freeze, it is all mechanical and requires no electricity, best of all you dont need a plumber to install, designed to be put under a sink that is furthest from your water heater, it basically creates an open loop in your plumbing system. I might get one, my hot water is frozen, im sick of boiling water to take a bath lol

Hot Water Lobster Intant Hot Water Valve Home Page

Hot Water Lobster Instant Hot Water Valve is an eco friendly circulation system for faster hot water, saving water, saving energy and pipe freeze prevention.

www.hotwaterlobster.com

 

[davey7]

TOH had something like this on recently...

I think Ask TOH had something like this on the show recently.

 

[philr]

I have a hard time believing that cold water boils faster than hot water. When I leave hot water in the electric kettle, even after an hour when I turn it on again, it boils almost immediately while it takes a few minutes for cold water to do the same!

 

When I was a kid, my father also told me hot water freezes faster than cold water to explain me why they used hot water to resurface the ice with a Zamboni at the arena. I didn't believe him and I told him it probably helped melting a part of the rough ice surface to do a better resurfacing... 

 

I thought about that again when I noticed that a hot water pipe I ran next to a cold water pipe would often freeze and not the cold one, but I thought that there must have been a better explanation...  I figured that the hot water pipe when unused dropped to the same temperature as the cold one since the water doesn't circulate and being just two inches away from the cold water pipe, nearer to a concrete floor and some air leak from outside was enough to make it freeze. The pipe would freeze even with a room temperature of 80°F.

That problem was quickly fixed with a can of foam insulation that did away with the small air leak!  A friend of mine has the same problem in the kitchen of his old house with "piece-on-piece" construction (I'm not sure how to say that in English, I hope you understand what I mean!). He needs to remove the lower panel on his dishwasher to let the air circulate and leave the cabinet doors open to avoid freezing. Otherwise, even the drain pipe of his KDSC-18 freezes...  He thinks the problem comes from a former kitchen remodel where they relocated the vent hood exhaust and didn't care re-insulating the hole adequately at the former location.  That makes sense but to correct that, he'd need to remove the cabinets and ceramic tiles on the wall and he's not ready for that yet... I suggested to simply cut holes in the floor under the cabinets/dishwasher as the basement is well insulated with urethane foam and he keeps it hot to have a warmer floor. He didn't bother doing that either so he just leaves the cabinet doors open and the faucet dripping...

 

[kb0nes]

Phil,

You are correct, cold water in NO way boils faster then water from a higher temperature. Yes it is true that heat flows through a thermal resistance faster if the temperature difference across that resistance is greater. But the higher temperature water has such an energy head start that any tiny thermal transfer advantage is moot. I ran a couple cycles with a recording thermocouple bringing 2 Kg of water to a boil, the 120 F water boiled in a fraction of the time the 50 F water took... Myth busted

My hunch is that freeze testing will prove out that any possible Mpemba effect is tiny and fleeting. I'm running some tests now on hot vs cold water freezing currently. I will post the results in a different thread once freezing tests are done. I'd have responded to my father in the same manner as you did regarding the Zamboni statement too.

In the case of household plumbing, with all variables normalized, I still believe there is no practical difference between the time either line would take to freeze. And given a tiny amount of flow, the hot will be less likely to freeze due to the additional heat energy the incoming water has.

If I had the issue of freezing in long lines running through an unheated crawlspace I'd install one of the hot water recirculation pumps as was posted up thread. Heat tape would work too but the recirculation system would be useful anytime as it reduces time to get hot water. Of course since it flows back through the cold line it would prevent freezing in both lines! The pump is simpler to install too as it is done under the sink, although the lines should be insulated too so I'd still have to get dirty if they weren't already insulated.