On Tue, 26 Aug 2003 00:09:34 +0100, "IMM" wrote:



For this, you could use a combi boiler, except that at the flow rate
you need, even a large one is going to fall short in cold weather and
you would be running the showers at lower than normal flow.
Two boilers could be used, but you need to watch out for the total
heat input requirement. A domestic gas meter (IIRC) is able to
deliver a supply for up to 62kW of heat equivalent and large combi
boilers are in the 28-30kW range,

Large? They can be much larger than that.

Typo, I meant 50kW.

Even at that heat input, e.g. a Micromat EC38 which has 46kW input for
DHW the flow rate for 35 degree temperature rise is only about 19
litres/minute, which is probably not enough for this application.



If using two combi boilers one can supply heating for downstairs and one for
upstairs giving natural zoning and both zones on separate timeclocks.


True, but two large boilers are going to require an upgraded gas
supply, I suspect. The issue is producing a large enough flow of hot
water to run a multihead and a normal shower simultaneously....

19-20 litres/min is probably not going to be enough.





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..andy

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