There is a company making these, with a relay controlled 80amp set of immersion heaters.
I recall the storage capacity was around 3000 litres and it had, unsurprisingly, thick insulation. I was asked to quote for removing it and fitting an oil condenser. We didn't get the job; frankly, I was relieved because this thing was enormous and the house had been reconstructed around it.
The customer found the running costs crippling even on Eco7 (which is of course what it was designed for), and the heat, as Mr Hailsham suggests, on colder days was used up by 7pm. At this point you can switch the immersions over to peak rate, and start paying 3-4 times more for the electricity. I was the only heating person round who could explain how it worked, which was worrying.
Anyway, mr cowboy Plumber, you are reinventing something and I think you would not be able to buy an unvented with a large enough capacity. Furthermore an unvented would be fabricated to withstand high pressures, which would be incredibly expensive for a unit of this size, and would not have enough immersion heater bosses. So just use an insulated tank, forget the unvented, that is ridiculous. Then you would need to build the contactors for the control system.
And the house would still be cold after 7pm.
I suggest you transfer your thoughts to inventing something we could fit under heavy loads to avoid carrying them.
I recall the storage capacity was around 3000 litres and it had, unsurprisingly, thick insulation. I was asked to quote for removing it and fitting an oil condenser. We didn't get the job; frankly, I was relieved because this thing was enormous and the house had been reconstructed around it.
The customer found the running costs crippling even on Eco7 (which is of course what it was designed for), and the heat, as Mr Hailsham suggests, on colder days was used up by 7pm. At this point you can switch the immersions over to peak rate, and start paying 3-4 times more for the electricity. I was the only heating person round who could explain how it worked, which was worrying.
Anyway, mr cowboy Plumber, you are reinventing something and I think you would not be able to buy an unvented with a large enough capacity. Furthermore an unvented would be fabricated to withstand high pressures, which would be incredibly expensive for a unit of this size, and would not have enough immersion heater bosses. So just use an insulated tank, forget the unvented, that is ridiculous. Then you would need to build the contactors for the control system.
And the house would still be cold after 7pm.
I suggest you transfer your thoughts to inventing something we could fit under heavy loads to avoid carrying them.
