It would in a busier household. With a hot water tank we'd be wasting heat, end up with hot water hotter than we (my wife) wants, though it would limit the time she would spend in the shower :)
Have you a product in mind? That was an idea I had in another post I made today (missed out on the Patent obviously).
There is nothing stopping you from running a cylinder with a combi - heating it as a separate zone on the heating. A small unvented cylinder can be feed from the mains cold directly.
If you want that and weather compensation then it gets slightly more complicated since you need split temperature operation - harder to find in a combi, but could easily enough be "faked" with a relay to swap the temperature sensor return with a fixed resistor that would tell the boiler it is very cold out so that it ramps up the CH temp to give hot enough water in the cylinder.
nah, more than that
You could also use 22m with microbore inside so it returns along he same pipe.
When power flushing or mains water flushing it is common to clomp each rad with a rubber hammer to help shift sludge into the circulating water. (you can also get a rubber nose to go on the end of a SDS that speeds up the process)
Stick a TMV on the output of the cylinder, and then it does not matter so much how hot it actually gets.
(Although running very hot in a hard water area will deposit more scale).
Might even be less - depends on the ground water temp.
Say incoming water is only 5 deg, and your target shower temp is 40 (what I would call a warm shower rather than hot!), that is:
(40-5) x 4200 = 147 kJ of energy required per litre.
A 3kW heater will transfer 3000J x 60 sec = 180 kJ per min.
180 / 147 = 1.22 litres/min.Even with incoming water at 10 degrees, it is still less than 1.5 lpm
yup you could... also lots of hassle unless installing a return pipe any other way is particularly difficult.
and you still have the problem of how to get the combi to re-heat it since many have a maximum cold water inlet temperature that is not particularly high.
40 is excessive for a shower, 30 is ok.
from 10 to 30C is 20deg rise which permits 2.1lpm
The hw doesn't return to the inlet, it returns to the tank, whether that's an external tank or a baby one in the combi.
Most people say body temperature is best:
I dug up my test temps. 39C at the shower head, 34C where water hits plastic. This felt a bit too hot, so nearer 35 sounds about right. You can cut it further with a drain heat exchanger. Good for showers, not for baths. You could play other games too if you want, like a hot harry preheater. And this was a standard shower, not aerated or pulsed jet. A comfortable 1kW shower should be quite doable.
and still way short of even adequate.
Unless it is specifically a storage combi (not that common in the UK), there is unlikely to be any way of connecting another inlet to its tank.
With an external tank sure no problem...
nonsense. The fashion for high flow showers is pointless.
Heh, return the HW back into the same connection you get it from, microbore inside 22mm. I shouldn't need to pont out that the ubore should be a little longer.
I think you need your flow rate recalibrated! High flow showers would be
15+ lpm - and possibly significantly more with larger soaker heads or body jets etc. Most folks idea of a "normal" shower would be something in the range 6 to 8 lpm.Very few people buy 7kW electric showers unless supply constraints rule out anything bigger, because they know the performance is so dire.
Screwfix have ~125 electric showers listed, the lowest power ones being
7.5kW - and they only have 2 models at that output.Perhaps I am missing something, but I can't wee what that would achieve with a combi.
The idea of a circulation loop is to ensure that hot water is available at the point of use with no delay. With some stored hot water you can pump hot water from the cylinder, round the loop and back to another tapping a bit lower down the cylinder. You are circulating hot water past the point of use so it will be hot when required.
If you are proposing that you tee into the DHW *output* of the combi, and pump back to that, all you will be doing is circulating cold water, since the combi will only fire when it sees an actual flow of hot water.
Mine is 42°C as it leaves the shower head.
Hotter the better I say - up to physical damage anyway.
My mum always used to say I had lily-livered skin
In a hotel I stayed at the other day the thermostat (detent peg) was set to 35C which I found to be cool. I raised the control to 45C which was comfortable BUT I don't actually know the actual temperature of the water, just what the control indicated.
Best bathwater is about 38 or 39C (by thermometer).
nib
Shower droplets cool pretty quickly in air
And the water entering a metal bath.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.