10-04-2017, 10:28 AM
You can't avoid the laws of physics. You need certain amount of power to heat a given amount of water to a given temperature in a given amount of time. The sums are easy enough once you've you've looked up the specific heat capacity of water. The result also depends on how cold the water is to start with. However I can tell you from experience that a 7kW electric shower is a pretty dismal thing. Not much more than a little squirt of really hot water or a somewhat better flow of lukewarm water. The 9kW and 10kW ones are a bit better. If you want a hot shower with a decent flow of water you really need 20kW+, something you can't really do with electric showers. Combi gas boilers usually give at least 20kW and so can give decent showers.
Of course if you can heat your water in advance of having a shower then you can do it with much less power, just takes longer. This is how traditional stored domestic hot water systems work.
Of course if you can heat your water in advance of having a shower then you can do it with much less power, just takes longer. This is how traditional stored domestic hot water systems work.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
