On 04/03/2020 10:02, Dave Liquorice wrote:
On Wed, 4 Mar 2020 09:10:07 +0000, Chris B wrote:

However on the cold side the entire volume of the cold supply pipe
inside the house (2 or perhaps 3 litres) will be warmed from 5C to house
ambient - say 20C. This must cause some expansion (volume increase may
only be an egg-cup full) and I am curios as to how this is dealt with.

The coefficient expansion of Water is highly nonlinear but from 10 to
20 C it's about 0.0001 / deg C. So 1 litre of water warmed by 10 C
expands by about 1 ml.

I'd be surprised if your incoming underground fed mains water is as
cold as 5 C even in a severe winter. 10 to 15 is much more likely.

No.

underground is seldom more than 9C and surprisingly stable year round

But it depends on how deep the pipes are and where the water in fact
comes from ... Borehole water is obviously colder than recycled London
urine...

--
Future generations will wonder in bemused amazement that the early
twenty-first centurys developed world went into hysterical panic over a
globally average temperature increase of a few tenths of a degree, and,
on the basis of gross exaggerations of highly uncertain computer
projections combined into implausible chains of inference, proceeded to
contemplate a rollback of the industrial age.

Richard Lindzen