Input water temperature for electric shower

[PEG]

Can i ask why you are not using the mains fed HW for a mixer shower set-up?

 

[jouleflow]

Hi - In theory, increasing the input water temp will mean the output water can be hotter for the same flow and power, or any combination of these depending on the heater controller’s capability. However, as has been said at some point it might just trigger the unit’s thermal protection and shut it down. If you can advise the make / model we might be able to be more specific.

This one lists max input water temp as 28C, for example.

View attachment 49166

That is a brilliant answer to my post, it confirms that it is not impossible to do, providing the input temperature is not excessive. I will now try to find similar details for my unit a Triton T80 easy fit.

 

[jouleflow]

Hi - In theory, increasing the input water temp will mean the output water can be hotter for the same flow and power, or any combination of these depending on the heater controller’s capability. However, as has been said at some point it might just trigger the unit’s thermal protection and shut it down. If you can advise the make / model we might be able to be more specific.

This one lists max input water temp as 28C, for example.

View attachment 49166

That is a brilliant answer to my post, it confirms that it is not impossible to do, providing the input temperature is not excessive. I will now try to find similar details for my unit a Triton T80 easy fit.

 

[jouleflow]

Can i ask why you are not using the mains fed HW for a mixer shower set-up?

We don't have a gas boiler so I can't guarantee there will be sufficient hot water available 100% of the time, especially using solar.

 

[Wilko]

Hi - here’s the Triton T80 spec, if that’s your unit. It shows 28 C as the maximum input water temperature on page 4.
https://www.tlc-direct.co.uk/Technical/DataSheets/Triton/T80Z_FF_Instructions.pdf

Just to say - I’ve not seen this done before.
The mixer will be key to keeping within the shower manufacturers specs. Perhaps confirm all flows and temps with power to the heater properly switched off.

Let us know how you get on

 

[jouleflow]

Hi - here’s the Triton T80 spec, if that’s your unit. It shows 28 C as the maximum input water temperature on page 4.
https://www.tlc-direct.co.uk/Technical/DataSheets/Triton/T80Z_FF_Instructions.pdf

Just to say - I’ve not seen this done before.
The mixer will be key to keeping within the shower manufacturers specs. Perhaps confirm all flows and temps with power to the heater properly switched off.

Let us know how you get on

Thanks Wilko. My plumber has a mixing valve that he uses for residential homes that is locked at 55 deg C. It is adjustable downwards & hopefully we can get it set to around 20/25 deg C. I expect this valve would not be affected by variations in flow as it is constantly adjusting to the conditions at the time. This lukewarm feed setup could also be used for other cold feed appliances such as dishwashers & washing machines. If you have excess hot water either from solar, gas or solid fuel then you could probably save money on these appliances too.

 

[PEG]

I do not know if you will gain any massive savings....the two inputs,to your mixer,will have to be the same pressure,to regulate accurately,at lower temperatures.
The element,for the higher setting,will still require the same usage,you will just get an increased flow,as it heats the warmer input,at a faster rate. You are then using more water,for the same length of shower.

You can calculate,the amount of energy required,to raise a known flow rate,at a known temperature,to the desired shower level. If the lower capacity element,can do this,then that may be worth it.

After a hard day's graft,i just want my standard flow and temperature,when in the shower,and i wouldn't be concerned about a saved penny.....in truth,i would not care,if the heat was generated,by two endangered species,being rubbed together...

 

[sam400]

I am not a fan of electric showers I don’t find the temperature control very good and they look ugly.

Can’t you use the solar circuit to heat water indirectly in an unvented then boost the final water temp using an immersion heater?
That way you can supply a mixer shower which will have far better temperature control and possibly flow rate.

 

[Zerax]

Jouleflow... it sounds like your 'energy storage tank' is a thermal store type solution, which is fantastic ! The idea with these is that they hold a large amount of water (water has a high 'specific heat capacity' so is ideal for this) that stores heat energy from a number of sources (log burners, solar pv and tubes, off peak grid etc etc.) that is then used for whatever it needs to be used for. The tank is designed to 'stratify', i.e. very hot at the top and cooler as you go down. Therefore, heat is taken out at the appropriate height depending for the temperature required. E.g. underfloor heating uses low temperatures, so it takes heat low down, but traditional wall hung radiators need high temps, so they should take heat higher up.

A coil of pipe inside is used to input or extract heat.

Therefore... what you want is 'technically' achievable as you just want to run your shower supply from a very low level in the thermal store, with some temperature control attached to it, so as not to have water >28°C

This is really a plumbing question rather than an electrical...

 

[jouleflow]

Jouleflow... it sounds like your 'energy storage tank' is a thermal store type solution, which is fantastic ! The idea with these is that they hold a large amount of water (water has a high 'specific heat capacity' so is ideal for this) that stores heat energy from a number of sources (log burners, solar pv and tubes, off peak grid etc etc.) that is then used for whatever it needs to be used for. The tank is designed to 'stratify', i.e. very hot at the top and cooler as you go down. Therefore, heat is taken out at the appropriate height depending for the temperature required. E.g. underfloor heating uses low temperatures, so it takes heat low down, but traditional wall hung radiators need high temps, so they should take heat higher up.

A coil of pipe inside is used to input or extract heat.

Therefore... what you want is 'technically' achievable as you just want to run your shower supply from a very low level in the thermal store, with some temperature control attached to it, so as not to have water >28°C

This is really a plumbing question rather than an electrical...

I agree that the post relates to plumbing but thought that solar pv users with free hot water would be more likely to have tried, researched or considered this, so I posted in the solar pv forum.