Chris Bottomley

Mike, I have sent you a reply to your message.

Steamy Tea: Regarding electricity demand: The total house demand: logged from the house smart meter by optical pulse counting over a two minute time period- kWh. ASHP and immersion electricity usage - measured by meters, meter readings read approximately every two minutes by the MMSP monitoring system installed with the ASHP- kWh. Solar generation: logged from the solar export meter by optical pulse counting over a two minute time period- kWh ReedRichards: The reference point for the 20% reduction was the ASHP as left by the installers: running unsheduled for heating at 45deg and hot water at 55deg, house temperature demand 20deg. Since then I have arrived at the following through various experiments: Hot water on a timer schedule to heat first thing in the morning. I may change this to late afternoon/ early evening to get most benefit from residual solar energy in the summer being diverted to the immersion. I know that this is less efficient in real world terms but it will end up cheaper for me due to the way that the FIT scheme works. House demand temperature reduced to the minimum we can live with (19deg) during the day and dropped by 0.5deg overnight. The heating is controlled by a wireless thermostat, we will move this to the coldest room when needed. We also use the short term temperature boost facility. Adjusting the thermostat to give longer on periods for the ASHP. Setting the ASHP to AI mode at the zero setting- the ASHP running between 30 to 40 deg. We were running it at AI +5 last year for a period but the default setting seems to heat the house reasonably well although the radiators barely feel warm. Essentially I followed the usual advice- to cut down on the heating cost reduce the house temperature to the minimum you can live with. The house is an extended detached 1960s chalet bungalow insulated as well as possible without extensive works. It has a 175m2 floor area and a combined heating and hot water energy requirement of about 20,000kWh according to our last EPC. The measured electricity usage of the 12kW ASHP was around 5,500kWh for the last year (February 21 to January 22), for the first full year of use (July 19 to June 21) the usage was around 7,100kWh. The caveats are this winter has been significantly milder here than last year and as there are only two of us in a relatively large house the heating in unused rooms is minimal.

Not sure what you mean by demand data, I log the time that the 2 way valve on the ASHP circuit is switched from the default heating position to hot water that gives me hot water demand. The time that the zone control valve on the radiator circuit is energised which gives the heating demand. I haven't found a way to monitor the demand signal for the ASHP directly but you can see it's on/off periods from its electrical usage data. MMSP is the Metering and Monitoring Service package that is an option when you sign up for the RHI scheme, it is an additional package that adds a degree of monitoring on the ASHP. I had the momitoring unit put in but the installers failed to follow up with the support package. From what I understand the take up of the MMSP option is very low. It, together with my additional monitoring, has proven useful as I have managed to reduce the ASHP consumption by around 20% by tweaking temperatures and schedules over my second year of ownership with little impact on comfort. Having said that it has been a releatively gentle winter so far in Somerset compared to last year.

Steamy Tea, sorry for the delay in replying- I only look at this board occasionally and the notifications I have set up don't seem to work. Yes it is a Raspberry Pi based monitor- I looked at the OpenEnergyMonitor system but decided that I couldn't get the combination of sensors and logging inputs that I wanted (mainly due to having an MMSP monitor already installed that I wanted to grab data from) without a lot of code hacking so I decided to build one myself. If I remember correctly it is a Pi 3B+, it runs a python program that executes a data logging cycle at two minute intervals storing the logged data in a MySQL database. The 2 minute cycle time was mainly driven by the MMSP monitor that also works on a 2 minute cycle, it seemed a reasonable compromise between resolution and data storage requirements as most of the parameters are slow changing. The data logged can be accessed as a plot via a web page using the HighChart plotting software and can be downloaded to a PC for analysis using SQL commands. All the sensors are home made as I didn't want to spend too much on it in case I couldn't get it to work. The data logged is: ASHP Energy Output, ASHP Energy Consumed, ASHP Flow Termperature, Internal Air Temperature and Immersion Energy Consumed: grabbed from the MMSP monitor. House Smart Meter and Solar Energy Generation Meter: optical pulse counters. Water Heating and Central Heating Demand: mains optical sensor on pump and zone valves. Heating Flow, Heating Return, Hot Water and External Temperature: DS18B20 one wire temperature sensors An example of the output is attached as well as a simple system outline drawing. My main reason for installing the monitor was to understand how the LG AI system worked as I now have the internal and external temperatures as well as the ASHP flow temperature available and can see how they vary. It was also useful in understanding the operation of the Honeywell Thermostat.

Steamy Tea- the smart meter and solar panel meter have LEDs that flash 1000 times per KwH usage or generation. I use a phototransistor over the LED to sense the pulses and count them over a two minute period and then convert to kWh.

ReedRichards- thanks have tried that and will see if that improves operation.

@Shark sorry for the delayed response I don't look at this forum too often. I have a PassivLiving MMSP unit installed. This was when the system was put in. As far as I know it has no direct connection to the LG Therma V unit, it only uses its own sensors. It uses the following metering: Sontex SuperCal 531 metering unit for ASHP output, flow rate? and temperatures Eastron SDM230-Modbus meter for ASHP power usage Eastron SDM130-M meter for immersion power usage Remote wireless internal air temperature sensor On top of this I have a home brew Raspberry Pi system that grabs data from the PassivLiving unit. It also has the following sensors: Heating and hot water demand Home power usage (Smart meter) Solar power generated ASHP flow and return temperatures Heating flow and return temperatures I have a Honeywell T3R wireless thermostat that was included in the installation and as noted in the discussion above it is debatable whether it is particularly suited to ASHP as it operates in a pulsing control mode rather than a pure on/ off as for old fashioned themostats. This has the impact of the ASHP only being on for short bursts (a minute or so) unless there is a big differential between the demanded and actual temperatures.

Going back to the note in my post about the time for the house to warm up and to reinforce SteamyTeas's comments. We had most of the radiators replaced when the heat pump was installed. The sizes were selected based on a full house thermal survey and in most cases the radiators were doubled in size. The slower house warm up time is probably based on two factors, the oil boiler was around 30Kw output, would run more or less continually while heating and ran the heating circuit at around 80 degrees. If nothing else the radiator temperature meant the house started feeling warm quickly. The heat pump is rated at 12kw and from the data I have probably very rarely runs at that output probably due to the reasons noted in the posts above and is running the radiators at say 35 to 45 degrees so at a delta of 16 to 26 degrees above nominal house ambient temperature. I know from the monitoring setup I have that the heat pump takes around one to two hours to raise the house temperature one degree. I don't know how quickly the oil system raised the temperature but looking back subjectively it felt that it could warm the house up much quicker. We would have the oil system on for three or four hours in the morning and again in late afternoon to late evening. It could warm the house within about an hour and recover the over night temperature drop. Using the heat pump to have the house at a comfortable temperature the most we feel we can get away with is to drop the demanded temperature by one degree overnight. This is not an issue, I was expecting the operation to be different when I installed the system and to be fair the installer's advice was to leave the heating on all the time. The point is that you have to run the system differently from an oil system and experiment to get the best balance between comfort and energy usage. With regard to the ASHP warmup time with our system is the heating is turned on and set on a schedule the heat pump will maintain the temperature in the buffer tank. This means that it will run approximately once an hour to warm up the tank even if the heating is scheduled to be off at that time. This gives you a quicker startup when heating is demanded as there is hot water in the buffer tank to pump around the radiators. The downside is that if the demand for heating is low there is a significant energy cost in keeping the buffer tank warm. I therefore turn the heating fully off once the outside temperature gets to the point that the need for heating is marginal. In theory this should be early April as we are in the South West but this May has been a bit of a challenge!

Ronny, Hello and welcome. We have had a 12Kw Therma V installed for a year now running a 15 radiator system and small underfloor loop in a reasonably well insulated 1960s chalet bungalow. As an indication our ASHP has used around 7800kWh over the last year with peak daily usage of of around 80Kwh on the really cold days. When heating the ASHP was set to run all day with a target internal temperature of 20 degrees during the day and 19 overnight. It is also providing hot water. The running costs are comparable with our old oil boiler feeding the heating and stored hot water. The ASHP consumption will vary dramatically with the outside temperature, as it gets colder the system has to provide more heat to the house but its efficiency also decreases as the outside air temperature goes down. Don't look at your smart meter on very cold days! I am hopeful of being able to reduce the running costs for the future by around 20% from what I have learnt in the use of the systems and controls in the first year. I hope that the efficiency improvements will come from: - Using the AI mode rather than a fixed temperature, this runs the radiators at between 35 and 45 degrees depending on the external air temperature rather than at 50 degrees all the time in normal heating mode as set by the installer. - Leaving the system running all day when heating to maintain the house at a set temperature. The ASHP has to run quite hard to increase the temperature of the house by one degree and it can take an hour or two to do this depending on the outside temperature. The controls have to be used on a very different way to the oil boiler as it could raise the house temperature farly rapidly. - When heating is not required over a period of time turning the heating off at the ASHP controller rather than relying on the timer thermostat. We have a heating buffer tank and the ASHP spends a significant amount of energy keeping this at temperature even when there is no heating demand. - Timing water heating to coincide with maximum sun energy, we have a solar panels.

@ReedRichards Interesting question about the benefit from the metering, we have the MMSP monitoring package but the supplier failed to support it so we don't get any money back from the RHI or the support that we should get from the supplier. On the plus side I think the supplier possibly got his pricing wrong in our benefit. The MMSP monitoring provides 2 minute readings of heat pump energy consumed and output, efficiency, flow temperature, internal and external air temperature (although as I note above I believe the external air temperature is from a local weather station not the data logger) and also immersion heater consumption. I also have logs of the solar panel output and can get can get downloaded data from the smart meter. What I do not have and would be very useful is heating and hot water demand logs so I can work out whether the heat pump is supplying radiators or hot water. Heating circuit flow temperature would be useful as would an actual outside air temperature reading for our location. Do we benefit from the extra monitoring? It has been useful to a certain extent in tuning the heat pump operation, for example you can see the energy used if the heat pump is just maintaining the temperature in the heating buffer tank when there is no heat demand. You can also see the correlation between the outside air temperature and the heating flow temperature which helps when trying to set the controller parameters for better efficiency. Due to the way the heat pump works you don't get nice smooth plots (see the attached screenshot) so you need to do a lot of eyeball estimation to work out average values and the impact of changes to the system parameters. I have done some manipulation on the data to smooth it and provide average values but I'm still working on the best way to use the data. In conclusion I think that we may get enough help out of the metering to reduce the consumption of the heat pump to get payback for the additional cost of the metering in 4 to 5 years as compared to what I would have been able to work out from just the basic energy consumption figures.

@ReedRichards I don't have any facility for remote operation of the system- being an ex-software engineer I like to keep things simple as I know that you can rapidly end up wasting time trying to get different systems working together. Not really something I have had to worry about as we have essentially been in lockdown since the ASHP was installed☹️ Like you I dont have any access to the LG temperature sensor, my external temperature readings come from the RHI Metering and Monitoring Service Package data we had installed however I'm pretty sure that there is no external temperature sensor in this, the readings probably come from the local weather station, Yeovilton in our case.

Apologies for the delay in replying, I haven't come back here recently. We had a heat loss survey done and the ASHP was sized by the installers based on that. The ASHP does run most of the time when the outside air temperature is near zero but it can heat the house well and acheive 20 deg plus internal temperatures if a high outlet temperature used (e.g. 50 deg). The interesting challenge is setting it up to get adequate heating at lower outlet temperatures to improve its efficiency, we can still get 20 degrees plus if required but it takes longer to get there. The sizing of the ASHP system seems OK as long as you don't expect to get the same sort of heating response as you would with an oil boiler rated at over twice the ASHP capacity and running a radiator circuit at 80 degrees rather than 40. The ASHP system is set to a more or less constant internal temperature demand when the heating is on as opposed to the oil system where the heating was off overnight, the oil system could of course raise the temperature back up in a couple of hours. You have to accept that if you have an ASHP the heating system has to be programmed differently and understand that the response time will be different.

@ReedRichards I don't know about the relevance historical records and how the AI mode works on the LG ASHP, hence my original post to see if anyone else had information. I'm basically trying to work out how best to set it up by making changes and looking at the impact on the flow temperature data and house temperature change response time. I have used the number settings on the AI mode, I'm not sure the numbers have any meaning they may be just increments as on a volume control e.g. turn the volume up to 10 (or 11 if you are Spinal Tap) . From memory setting the AI mode to +5 increased the flow temperature by around 4 degrees, going to -5 had the opposite effect. This was when the system was running at flow temperatures in the mid to high 30s at the AI 0 setting. If the operating temperature range is different the AI settings may have less or more effect Our system is set up to use the internal hot water temperature sensor and an external Honeywell programmable thermostat. The hot water is programmed as schedules in the LG controller to come on around mid day when there is the best chance of output from the solar panels. The heating schedule are controlled by the Honeywell themostat, it is essentially on all the time but we drop the demanded temperature overnight. Our controller Select Temperature Setting is set to Water I assume as we have the external temperature stat but I could be wrong. I haven't been able to find any firm information as to what this setting means. I wouldn't want to use the temperature sensor in the LG controller as it has been installed in a location in the house that get quite warm when it is sunny. The Honeywell stat is in a more representative position for the overall house temperature.

Hogboon, With regard to the data recorded by the LG system that is accessible via the remote controller see my reply to your posts in the LG Therma V Mono Block Air Source Heat Pump Thread. As far as I know you will not get a log of the heat pump output from the LG system, our remote controller is at the same software version as yours and I can't see any way to get it. I can get this information for our system but we have an external data logging package installed with a heat meter, temperature sensors, heat pump and immersion consumption meters (RHI MMSP). This gives a COP figure for our system but it can be quite sobering to actually see what the real world figure is- our system is in the region of 2 to 3 when heating. With regard to plugging a laptop directly into the ASHP I would expect that you would need an LG software app installed on the laptop to talk to the ASHP, I suspect this would almost certainly not be available to the general public unless some one has got hold of the interface protocol and written their own version..

Hogboon, We have a similar setup to you except that we have a Honeywell programmable thermostat controlling the heating. This overides the room temperature sensor in the remote controller. We have the heating set to on all the time and just drop the temperature 1 deg overnight. The Honeywell thermostat is not as clever as the Nest, the heating comes on when you set it, it doesn't try and anticipate the demanded temperature by starting the heating early. Our house has a similar thermal inertia to yours- on an average winter day it takes an hour or two for the ASHP to raise the remperature by 1 degree, over the recent cold spell it could take most of the day to come up one degree. This is with the radiator circuit running at around 45deg. When it was installed we had the system running at 50 deg for the ASHP heating flow, the house was warm enough but the electricity consumption was rather frightening. At the moment I am trying to find the best compromise between radiator temperature and electricity consumption- hence the playing around with the AI/ Auto mode on the LG remote controller rather than using a fixed heating circuit temperature. My understanding is that the AI mode uses an internal algorithm to adjust the ASHP temperature based on the outside and internal air temperatures. Basically I think that as the outside temperature goes down the ASHP flow temperature is increased to compensate, the internal house temperature may also have some influence on the flow temperature. Unfortunately with the way our system is configured the ASHP flow temperature was in the range of 30 to 40 deg which was too low for our radiator installation- I am currently trying to tweak the settings to give a higher maximum temperature. With regard to DannEvs post, as he says the data logging information is accessible through the remote controller but you have to be in the Installer Setting mode to get to it. To get to this you need to have the Setting icon (cogwheel) selected. With the "cogwheel" highlighted press and hold the up arrow key ( ^ ) for three seconds. An enter password screen with 4 boxes will be displayed. The password is the software version number, in your case I think this is 3055. Use the arrow keys to enter this and you should then be presented a long list of menu options. The data logging oprion is near the bottom of the list. This displays a list of around 50 lines of the latest data logged at what looks like about 12 minute intervals. The data appears to be: - Date/ Time - Operation Mode - Heating set temperature - ASHP in/ out temperatures - Hot water operation/ target and current temperatures - ODU- I don't know what this is, nothing is registered on my system. - Error- again blank My guess is that with a laptop plugged into the ASHP the installers will get a more detailed and a much longer history of data. A caveat on the above- I do not have much information on the operation of the LG Therma V system so much of the above has been worked out using a general control systems and engineering knowledge background based on the operation manual and observing the operation of the system. I have had no support from the company that installed the system- lesson learnt there. If you do go into the installer menu do not change anything unless you know what you are doing and make sure that you have a record of the original values as installed so that you can go back to them.