Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Vincent Magno on 06/02/2011 23:30:03

Title: How can I stop an outside tap from freezing?
Post by: Vincent Magno on 06/02/2011 23:30:03
Vincent Magno  asked the Naked Scientists:
   
This winter has been very cold and I'm concerned about my pipes freezing.  I saw an inexpensive outdoor tap cover at my local hardware store. 

The cover appears to be no more than a small insulated box that goes over the outdoor tap handle and fits snuggly against the exterior of the house. 

The cover will obviously protect the tap from snow and wind, but can the temperature inside the cover be any higher than the temperature outside?

Vinnie from New Jersey, USA

What do you think?
Title: How can I stop an outside tap from freezing?
Post by: yor_on on 08/02/2011 04:32:18
Well let's assume that you have flowing water in your pipes, to be flowing they should be above freezing although how much I don't know, you can have water not becoming ice being under the normal freezing point too. "the “temperature alert threshold” is 20 degrees F. This threshold is based upon research conducted by the Building Research Council at the University of Illinois. Field tests of residential water systems subjected to winter temperatures demonstrated that, for uninsulated pipes installed in an unconditioned attic, the onset of freezing occurred when the outside temperature fell to 20 degrees F or below." You can also use old newspapers to insulate and wrap them around 'whatever it is' with some tape or string.

The idea generally speaking should be too use the heat coming from the running water, and other heat factors, transported in the metal, combined with what insulation you use, storing the heat instead of loosing it to wind chilling effects, that can be quite strong. If it gets really cold try to empty the pipes outside, closing it of inside and then open outside. I don't know what the temperature of the cold water you have is. It also depend on the pressure how long water will keep flowing/running.
Title: How can I stop an outside tap from freezing?
Post by: Geezer on 08/02/2011 04:52:52
You should get a frost free faucet. Here you go

http://www.ehow.com/about_4743025_frostfree-outside-faucets.html
Title: How can I stop an outside tap from freezing?
Post by: syhprum on 08/02/2011 16:16:44
A frost free faucet does not really solve the problem, the purpose of an outside tape is to have a supply of water when you have no access to the inside of the house.
I see two solutions you must have a source of heat coming down the pipe controlled by a thermostat that maintains the pipe above freezing regardless of the outside temperature.
This is a rather expensive solution the other way is to have an electrically controlled valve that can be operated from outside that will allow water into the pipe after it has been electrically heated to above freezing point.
These solutions might seem over complex but might be justified if the purpose of the outside water supply is to put out fires. 
Title: How can I stop an outside tap from freezing?
Post by: Geezer on 08/02/2011 18:31:27
A frost free faucet does not really solve the problem, the purpose of an outside tape is to have a supply of water when you have no access to the inside of the house.

That's what a frost free faucet does.

The actual valve is inside the heated space inside the house. You can obtain water any time by opening the valve from outside the building. When you close the valve, the water drains out of the pipe so that it can't freeze up.

I have one in in my garden. The valve is about four feet underground - well below the frost line - and it never freezes up.
Title: How can I stop an outside tap from freezing?
Post by: syhprum on 08/02/2011 18:52:29
Trust me to devise a complex solution to a simple problem, I should have read the brochure more carefully.

I notice they perpetuate the old myth "bursting the pipe upon thawing", of course the pipe bursts when it freezes it is just that we notice it when it thaws !! 
Title: How can I stop an outside tap from freezing?
Post by: Geezer on 08/02/2011 18:54:45
Trust me to devise a complex solution to a simple problem, I should have read the brochure more carefully.

 [;D]

Actually, I don't remember seeing anything like them in the UK - probably because it never gets below freezing there  [::)]
Title: How can I stop an outside tap from freezing?
Post by: syhprum on 08/02/2011 19:00:23
We had -10°C in Kent back in December, -20°C in parts of Scotland.
Pretty mild by some standards but enough to burst pipes
Title: How can I stop an outside tap from freezing?
Post by: yor_on on 09/02/2011 19:49:37
It's a deceptively simple solution to a complex problem Geezer. I liked the idea of letting Earth warm the valve.