Should I turn it off? (Water valve in wall)
 

I own a condo in a 28 unit strata. The main water tap outside runs off my main water valve. I live in a fairly mild climate so pipes don't often freeze but should I turn the exterior water off to prevent any loss of heat to my unit? I have already insulated the shut off by notching an abs threaded cap around the pipe and filled it with expanding foam. before I did this you could feel cool coming out of the hole. Will the cold water running through the pipes cool the interior of the wall enough for me to worry about? the wall is an interior wall so no insulation. Some people may get cranky if I shut off the water?

if the water isn't being used it should sit in the pipe and gradually come up to the same temp as inside by stealing the heat from inside. This is a trivially small amount of energy compared to that air leak that you sealed up. I wouldn't bother turning it off.

It actually will cool off the interior of the wall... some. If you are worried about it, you could tear off the sheet rock and insulate the pipe with some really good foam pipe insulation (don't use the cheap stuff). It might cost you over $500 to have it done or you could do it your self for maybe $100 in materials and a couple of days of disaster.

On the other hand, if you're concerned about very small heat losses, you might consider investing in a cat as a source of heat to offset the cold-pipe losses.

Best,

-AC

:D Haha thanks! Has anybody done the math to figure out how many BTU a cat is worth? I have two but cat food is a pretty expensive heating fuel :D

At least here they sell foam caps that you can put over outside water taps in the winter to keep the heat loss down.

Looks like thst faucet is not a freeze proof one so you might want to shut water off to it then open outside faucet to let it drain. Do people use the outside faucet in winter and that is way they will be mad? If you install a frieze proof your problem is solved

thanks everyone, I will look for a cap that sounds like a good idea. If it does get cold enough to freeze then it would be in my unit so I should do something just incase. The water doesn't get used often but people still use it occasionally, washing cars and stuff. It is actually more annoying in the summer! it is constantly on with sprinklers and car washing. insulating the pipe might be worth it just for the sound. I am sure the strata would pay for material if I complained.