On Sun, 26 Dec 2010 21:22:32 +0000, Tim Streater
wrote:

In article
,
MM wrote:

On Dec 25, 4:000m, Tim Streater wrote:
In article
,


M wrote:
I've been puzzling how modern pipe insulation works. If the
temperature in a room is constantly at 0 dec C, then surely EVERYthing
in the room - pipework, insulation etc - is at the same temperature?
(Given that there is no hot water flowing through the pipes.)

So what actually does the foam insulation around pipes do to protect
them?

1) Why would the temperature in the room be at 0C constantly?

Why not? It was only an assumption.

2) Water flowing through the pipes will be hotter than that, and the
insulation thus prevents heat loss in the situation that the room is in
fact at a low temperature.

I couldn't care less about *hot* water pipes. It's the cold ones that
worry me.

What makes you think I was talking about hot water? I just said that
water flowing through the pipes will be hotter than that.

You're talking about a temperature differential of around 3 deg C as
"hotter", I suppose? Anglian Water have been saying they've never
experienced such low temperatures of their piped water as this
December. However, no water is flowing while I'm away. Maybe it's a
good idea to turn on some taps a little so that the water in the house
is not static for long periods.

MM