"David W.E. Roberts" wrote in message
...

"IMM" wrote in message
...

snip
First choices for a hosue should be:
- combi, or two combi's.
- heat bank (can combine the full kW/hr outputs of a boiler and the heat
banks stored water)

Assuming the mains pressure is adequate for the above.

Surely that is the point.
There must be a level of demand (mainly judged on house size and number of
bathrooms) which cannot be satisfied by the average mains water supply
(and
possibly gas).

Once into very large domestic houses you are in a grey area of commercial
systems. Many large houses do have Commercial gas supplies and
water/heating systems.

BTW, there are commercial combi boilers, which give 40 litres/minutes and
above, etc. Some are fitted in banks. The reason they are used is that the
users have a continuous demand for hot water. Take a health centre for
e.g., people are coming and going all the time, so having stored water
would entail a "very" large space consuming cylinder and boiler(s) for the
showers. Having combi's which will produce 80,100-120 litres min for the
showers is ideal as they never run out of hot water. the control system can
be arranged to bring in boilers as demand rises. The ideal solution for that
problem.



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