Why isn't cold water room temperature?

The water that comes out of the tap when I turn on the cold tap is cold. It’s really cold. I don’t find much of a difference between summer and winter - it’s always really cold. Why? Shouldn’t it be more in line with ambient temperature outside? Sure, the pipes delivering it are underground, so it’s not like it will heat up to outside warm temperatures when it’s hot out, but should it really be difficult-to-keep-your-hand-in-the-stream-because-it’s-so-cold cold?

Yes, if you live in the Frozen North. :smiley: Water comes out of the tap at “ground temperature”, because the water pipes that bring it from the water treatment plant through the city into your house are buried in the ground. Water pipes are buried below the frost line, so they won’t freeze and burst. So this means that in the winter, water traveling through the pipes up into your kitchen can be as low as 33 degrees. “Ground temperature”.

If your water pipes were designed to be at outside ambient temperature, most of the year they’d be frozen, and inoperative.

And the water pipe only comes up out of the ground right at your house, usually through a water main down in the basement, so in the moments that the water takes to travel through the few feet of pipe through your house between the entry point in the basement and your kitchen tap, it doesn’t have enough time to warm up to your home’s ambient temperature.

And you live in Calgary (heh–gloat), where the water pipes are probably buried at least 6 feet deep, and where the ground doesn’t get much of a chance to warm up during your pathetically brief and chilly summer. (* snerk *) :smiley: So the water that comes out of the tap is always difficult-to-keep-your-hand-in-the-stream-because-it’s-so-cold cold.

Just wait til global warming drys out the water supply in Illinois.
Then the smirking will flow in the opposite direction ! :stuck_out_tongue:

The earth is a great heat modulator. If you’ve ever visited a cave the guides will tell you caves are about 50F all year, regardless of the weather above. Same for your buried pipes.

I’m in Calgary too, so I know exactly what the water feels like now. If you leave your taps off for a few hours, the water will be warm for a few seconds when you turn it on. Within 15-20 seconds all that volume of water from the piping in the house is gone, and replaced by water from the mains in the ground outside, which is probably around 5C or less.

Stick your head outside right now, and it’s not hard to figure out why the water’s so cold; you heard on the news about some big water mains bursting recently due to freezing? That tells you how cold the ground is even at the depth those pipes are buried at. Add to that the source of your water - it’s either from the Glenmore reservoir or the Bear’s Paw reservoir, both of which are covered by tons of ice right now… and they don’t heat that water up before they send it down the lines to us.

And actually there is quite a difference in water temperatures from winter to summer; I run a dozen big fish tanks in my basement so I’ve measured the temp during both seasons. In summer the water’s about 15C, and now it’s about 10C colder. That pretty much does reflect mean ambient outdoor water temps.