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Optimising LG Therma V R32 using AI

AndyJ · 2023-12-29T23:58:41Z

This is my first post, so please be gentle. System is LG Therma V R32 (14kW). House detached 2 floors 2700 sqft, self built - mid-90's. Well insulated for it's age, underfloor heating downstairs, radiators upstairs. Solar Thermal panels for hot water (sunlight permitting). Location Hampshire. Installed around 2 years ago - initially set with flow temp around 55C and controlled by 2 separate Nest thermostats - one for downstairs ufh and the other for the upstairs radiators. In practice only the uf/h is used for heating, as although its a 5 bed house - we're now empty nest, so only 2 people and prefer bedroom to be cool at night. Haven't paid much attention to the system since it was installed, although have reduced the flow temp to mid 40's (as hot water is set to 43C - so had assumed flow temp needed to be set to slightly higher). Getting fed up with high winter electricity usage (£20 per day), have started to look at ways to optimise. My initial thought was to introduce individual control for each ufh zone (room), with smart thermostats controlling each zone via actuators (currently all ufh loops are balanced and operate as one controlled by the single Nest in the central hallway. However, after reading a number of posts on this forum and studying online manuals and some videos, have started thinking using the Therma V's AI weather compensation and optimisation functions might be a better (and more cost effective) approach. I.e. the system is best optimised by allowing it to run continuously and adjust the flow temps automatically. However, finding some straightforward and simple to follow instructions is proving challenging. Hoping someone on here can perhaps fill in some gaps. I have activated AI, and also entered the installer set-up, and followed basic set up instructions, but not really understanding what I'm doing. I'm normally quite tech savvy (IT background) but at the moment this has me at a loss. The ASHP controller is upstairs in the hallway so could potentially be used as a temp sensor (air?). I initially set for water sensor only, and input some values for Outdoor and indoor temps for Auto mode, and also LWT settings. However, I have found nothing that explains how setting these values affects the operation of the ASHP. I'm presumaing the idea is that the configuration sets up a rel;ationship between the water flow temperatures and the outside air temperature. (I.e. as the temperature decreases outside, heat loss increases and so more energy is required to keep the house at the required temperature (i.e. increased flow temps). What I'm unclear about is where, if anywhere, is the controller set with a target house temperature value? After activating AI mode, the flow temperatures have ranged between 32C and 37C and is holding the house at 18C but not increasing to the required temperature of 19.5C. I'm unclear where or how to change settings to increase the flow temps (or other settings) to create the desired outcome. Suggestions and any clarifications on how the AI settings actually work on this would be much appreciated. Thanks.

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Air Source Heat Pumps (ASHPs)

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Tim441

(@tim441)

Prominent Member Contributor

Joined: 3 years ago

Posts: 327

07/01/2024 5:20 pm

My Grid import for last week:

1 Jan 41.5kwh

2 Jan 25.21kwh

3 Jan 30.1kwh

4 Jan 37.1kwh

5 Jan 39.55kwh

6 Jan 44.2kwh

we wfh so in all day.

Grid import:

2022: 10158 not using weather comp/AI

2023: 8225 using wc/AI

Also note:
we used a hot tub quite a lot in 2022 but used less in 2023. Impacted grid import and solar export.
we have an elec car since June 2023 so actual comparative for 2023 will be under 8000

Its complex making exact comparisons even though i try and keep a spreadsheet. so many variables! e.g. We sometimes import from grid to fill batteries and sell back to Octopus for profit in Saving Sessions and also in 2022 when prices were all over the place.
hot tub usage
e/v

Overall I'm absolutely certain our usage is reduced by WC/AI

Listed Grade 2 building with large modern extension.
LG Therma V 16kw ASHP
Underfloor heating + Rads
8kw pv solar
3 x 8.2kw GivEnergy batteries
1 x GivEnergy Gen1 hybrid 5.0kw inverter
Manual changeover EPS
MG4 EV

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Tim441

(@tim441)

Prominent Member Contributor

Joined: 3 years ago

Posts: 327

07/01/2024 5:28 pm

with regard to tariffs etc.... I do not have any Home Automation and have not looked into it a lot. Can the LG be integrated easily?

My tariffs are:

Import: Octopus Tracker (daily tracker not Agile)

Export: Octopus Fixed (15p)

I use Tracker for a number of reasons:
1. My inverter is only 2.6kw so I can't fill batteries very fast during cheap periods and can't draw from batteries very fast. So i need to use grid at all times.
2. With maximising WC/AI I prefer to keep constant running and not be having to control for tariff reasons

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Tim441

(@tim441)

Prominent Member Contributor

Joined: 3 years ago

Posts: 327

07/01/2024 5:39 pm

On solar...

I have 2 systems:

Original 7 panels 2kw. Pitched roof - south facing
on FIT but now transferred to actual export payment instead of assumed. Produces circa 1500kw pa

New system: 20 panels 6kw. 6deg/flat roof - east facing. Good sun until mid afternoon
Produces circa 5000kw pa

New system includes 3 x 8.2kw GivEnergy batteries
1 x GivEnergy Gen1 hybrid 5.0kw inverter

newer kit has advantage of ability to import/export at higher rates than mine

recommend looking at utilising emergency power supply - preferably with a gateway such as Tesla, Solaredge or Givenergy All in one so that it auto changes over.

Many installers don't bother to point you at EPS options!

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IanS

(@ians)

New Member Member

Joined: 2 years ago

Posts: 1

10/01/2024 12:41 pm

@derek-m If you navigate to the UK LG Therma V heat pump owners group on facebook you will find a complete setup doc for AI I pulled together after my own struggles to get this right. Look in files section V2.

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Derek M

(@derek-m)

Illustrious Member Member

Joined: 5 years ago

Posts: 4427

10/01/2024 6:03 pm

Posted by: @ians

↑

@derek-m If you navigate to the UK LG Therma V heat pump owners group on facebook you will find a complete setup doc for AI I pulled together after my own struggles to get this right. Look in files section V2.

Hi Ian,

Thanks for the link but I am not a facebook user, have never been and doubt that I ever will be. Just a friendly old dinosaur. 😋

👍

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