LG monobloc and solar panels losing half tank

[stuartg]

I have a head height problem for the storage tank and needed a solution that would allow the monobloc to heat from the bottom of the tank
I have now sorted the issue with 2 tanks in series, both single coil
The smaller one has solar heating and this then provides cold, warm or hot water to the larger one that then uses the monobloc to raise the temperature if required
Comments would be very welcome
This solution also allows solar to be simply added later to an existing installation.

 

[oz-plumber]

All looks ok as long as you have necessary check valves, pumps and temperature sensors and controllers set up correctly.

 

[stuartg]

All looks ok as long as you have necessary check valves, pumps and temperature sensors and controllers set up correctly.

Yes I've had temperature bypass valves in the past to ensure hot water gets priority over heating circuit
I installed the existing system with a plumber installed boiler
My aim is to eliminate gas completely next year with all electric cooking, and I'm investigating using the garage roof for electric solar panels as wel,l to reduce electricity purchase

 

[RoryD]

I have a head height problem for the storage tank and needed a solution that would allow the monobloc to heat from the bottom of the tank
I have now sorted the issue with 2 tanks in series, both single coil
The smaller one has solar heating and this then provides cold, warm or hot water to the larger one that then uses the monobloc to raise the temperature if required
Comments would be very welcome
This solution also allows solar to be simply added later to an existing installation.

Is there not a compatible twin coiled cylinder that could accommodate solar and the heat-pump?I appreciate that the temp sensors wold be an issue but using relays to close off would be an option. If you have 2 x unvented cylinders what issue are you having with the head?

 

[stuartg]

When I say head height, I mean that the available ceiling height under the stairs is less than any dual coil tank where there are 120 litres of hot water at the level of the heat pump coil, assuming that the solar coil is only warm or cold even. I have nowhere else that I can put the tanks in my bungalow, and it is central which means that the hot water doesn't have far to go to any of the hot water outlets, bath, 2 basins, utility sink and kitchen sink. I have redrawn the picture to make it clearer

 

[oz-plumber]

Without getting overly technical, your system will work fine when the sun is shining and you don't have much requirements for heating.
But in he throws of winter, without any Solar Gain, you may be needing.
ASHP's reduce outputs significantly when the ambient temp drops below 7C, and reduce dramatically as the temp gets lower.

Before you rely totally on your system, have a deeper look into the ability of your heat pump system when temps are >7C.
See if your system can maintain the requirements to keep you warm and adequate hot water

Don't want you to spend a winter with minimal heating and tempered hot water.

 

[stuartg]

From experience of other people who we know and trust, they do not suffer that way using such a system
The recommended size for our property is less than 8kW and the pump we are buying is 9kW
Our house is well insulated in cavity, loft and underfloor.
We have a solid fuel burner in the sitting room and both tanks have backup immersion heaters
The cost of electricity is not a major problem, but we intend putting electric solar panels on half our garage roof, which is south facing, in the next 18 months.
We only had three days of frost (scraping windscreen first thing in the morning) last winter, and none the previous one.
So on balance, I will take the risk. I don't want to be in an almighty rush in a few years time. And I really don't want air polluting gas any more.

 

[Ant87]

Just check the drop off temperatures for your LG, I have never had much to do with LG but manufacturers such as Samsung, their 8kw heat pump will not give 8kw when it's -3 outside, it will only give around 6kw (@50degC).