Electric Showers - KW and relation to pressure/flowrate

[TheCat13]

Hi Guys and Gals,

Something that always keeps me guessing is the relationship between an electric showers KW and whether you get a higher water pressure. I know that the higher KW showers heat the water up quicker but is that where it ends.

Is there a calculation relating the the KW difference for advising as to the difference in pressure if any. Is an 9.5kw 10%(ish) more powerful than an 8.5 for example

Is it really worth upgrading a cable from 6mm to 10mm (plus fuses etc.) and installing a higher KW shower, will the customer notice much of a difference?

Customers often ask me, my electric shower pressure is crap, what can I do. I know there are several options of varying cost and work(i.e. mixers with pump off gravity), but can it be simple matter of upgrading the cable/fuses and shower KW.

There we go, knock yourselves out on the answers folks, hopefully some will match up! l

 

[simond]

If you are in the trade I would expect you to know that the larger the Kw input, the greater flow rate of water can be heated through a given temperature rise.

The pressure is not specifically affected by the Kw heater rating, that is another rather surprising comment from someone in the trade. At a higher Kw, a proportionally greater flow rate can be delivered at the same temperature rise.

Until you get a 24Kw electric shower, you are not going to rival a shower off a gas combi. The would be 100amps, single phase, on 24mm tails.