Unvented hot water cylinder

[trevorbayliss]

I am renovating a flat and it will be all electric.

I was thinking about using electric shower and water heaters for the two sinks.

But i am thinking a better solution will be an unvented HW cylinder.

Any idea on what size i might be needing ? I was thinking max 90L.

The flat will be a holiday let, have two bedrooms and have one shower. There is a kitchen sink and a bathroom sink. So it is not a big place and it is only going to be used for max 140 days per year.

Also can these cylinders be controlled by the internet ? There seems no point in heating water if the place is going to be empty say mon-thursday.

 

[ianmcd]

yes can be controlled by the internet , 90 L is a bit skimpy though to be honest, if that requirement is because of space restrictions, then you are stuck with that, but if simply because of price go larger, better to let your tenants have a good experience and recommend the place or return than just skimp on a 10 minute shower and waiting to reheat before anyone else can have a shower, most modern cylinders are extremely efficient, if you are going to control by internet though, be aware of legionella regulations, some internet controllers incorporate this

 

[oldbutnotdead]

Yes unvented dhw will give a much better shower experience than an electric shower, long as the water pressure and flow are up to it. And go a bit bigger if you have the space-150 or 200l.
There are shedloads of controllers that will do the job. I'd suggest putting in a chunky relay to power the immersion heater(s), some of the smart things I've fitted are allegedly rated to 13A but get very hot and bothered at that load.
Whichever smart thing you get, make sure it includes a manual override (ideally an integrated pushbutton rather than a latching switch) so if the device loses connection your tenants can get some hot water.

 

[trevorbayliss]

This is to be our flat as well, so dont want to skimp. I have checked a 10 min shower uses about 100L water. So really need a bigger unit. 150L is probably the size to go for. Space is not great.

 

[flameport]

I have checked a 10 min shower uses about 100L water.

Not all of that water will be hot.

 

[oldbutnotdead]

If space for a cylinder is really tight you could put a separate instant water heater in for kitchen sink so the cylinder was just for the bathroom. And as above re the heat, if you keep the cylinder at 65 (legionella killing temperature) then about 30% or more of the shower water used will be cold