Flow rate of new shower

[Adrian]

I mean, we don't use the hallway just inside the front door for much. It'd be just fine...

[Johnny B Good]

Using the more useful data from the #10 setting (4.0 litres per minute) we have 9000 x 60 joules heating 4 litres per second's worth of water or

9000x15 joules per litre. divide this by 1000 to get a joules per cc of water figure and then divide the result by the 4.2 conversion from calories per cc to each deg of temperature rise and we get... 9x15/4.2 = 32.1428 degree temperature rise. A mere 3% departure from your measured temperature rise! I'd say the answer, as far as setting #10 is concerned, is a resounding YES! :-)

When you consider parasitic heat losses, your data seems remarkably consistent with an exact 9KW consumption by the heater cartridge before even taking into account any tolerance errors introduced by your test measuring equipment.

You should be proud of yourself. I'd say you're now ready to measure the temperature rise of a half litre of water in a plastic measuring jug to check the efficiency of your microwave oven (also needs an accurate wattmeter if you want to go by actual consumption rather than what's on the rating plate). :-)

[Johnny B Good]

====snip====

Or, put more simply, "It is what it is." :-)

[Tim Lamb]

But you would then have to route that slightly warmer than ambient water to somewhere it could be usefully used!

[pamela]

Your calculations have lost me but they seem to accord with what others have found by different approaches.

I would never have guessed that my readings were so accurate because the bucket was on the slight slope of the shower floor and I wa s abit vague to myself about whether I measured the fill to the mark on the near or far edge of the bucket.

The microwave suggestion sounds interesting but I am not sure I am up to the challenge at the moment.

In fact I do measure things and it's become so much easier in recent years with bargain price digital thermometers, weighing scales, thermometers, multimeters, and so on. Oooh, arrrh, the kids of today don't know how hard it was in the old days to weight something accurately because now they can get a semi-decent scale which will weight accurately enough to the nearest gramme for under a tenner including delivery.

I remember reading some discussion online by an unhappy a poster because his two digital thermometers read the same temperature 0.5 degree apart. He didn't know he was born! Measuring temperatures at home to within half a degree in the old days was the stuff of dreams.

[tabbypurr]

£50 is very little trouble. There is really no upside to lagging it, the total heat loss is trivial, and lost into the room anyway.

NT

[tabbypurr]

e total heat loss is trivial, and lost into the room anyway.

In winter, heat loss to the room doesn't matter, it's not loss. In summer i t is. Incoming water maybe 10C, shower head temp about 40, so with a 50% ex changer you get a cold feed to the shower of - brain not working but it's l ukewarm only. And it operates for what, 20 minutes in every 24 hours = 1.

33% of the time. If you're going to lag something, putting the lagging on t he DHE is a lousy choice.

NT

[Brian Reay]

The laws of physics haven't changed. If you were happy with 3kW, then it is difficult to understand why you are unhappy with 9kW. Logically, your being able to notice a change between a 3kW shower and a 9kW shower is far more feasible that your noticing any minor loss in efficiency of a 9kW shower. Or even the difference between a 9kW shower and a 7 or 8 kW one.

We have a 9kW shower and, even though I like a hot shower, I only set it to about 2/3 of the maximum temp setting.

[Tim+]

Sense of humour failure. I strongly suspect that the comment "plenty ample" was tongue in cheek.

Good for you. We used to think that the performance of a Morris Minor was adequate too. People's expectations move on. I doubt the OP is interested in what you consider adequate.

Tim

[pamela]

Nowadays I like a powerful shower and for years I used a non-electric shower fed direct from a large combi boiler. By comparison the new 9kW shower is not bad but it leaves me wanting a better flow.

Elsewhere in this thread Graham said if you are used to a "proper" shower, a 10kW electric one will seem barley adequate. I agree with him.

Last year's luxury is this year's necessity.

[Tough Guy no. 1265]

I can burn my skin off with a 7kW shower, but then the flow rate is VERY low on that setting. If you want a torrent, live near a waterfall, now that's a shower.