immortallt Posted January 17, 2022 Share Posted January 17, 2022 Thank you very much for sharing your experience. Though 4 MWh of electricity seem quite excessive having in mind its +12 degrees in Durnham now. Nonetheless, energy efficiency of the buildings probably differ (we have close to passive house) and only two people using hot water. Anyway, once again, thank you for sharing your experience! Link to comment Share on other sites More sharing options...
ReedRichards Posted January 18, 2022 Share Posted January 18, 2022 If you think 4 MWh is excessive, compare it with my 6.9 MWh used in a year. But I live in a bungalow built in 1980. I looked to see where Durnham was but could not find it except as Durham misspelled. Link to comment Share on other sites More sharing options...
immortallt Posted January 20, 2022 Share Posted January 20, 2022 On 18/01/2022 at 10:56, ReedRichards said: If you think 4 MWh is excessive, compare it with my 6.9 MWh used in a year. But I live in a bungalow built in 1980. I looked to see where Durnham was but could not find it except as Durham misspelled. Reed, in a year - that is understandable. I use pure electricity about 4 MWh and additional 3 MWh in solid fuel for the heating season for our 170 sq.m. (no heat pump, just pure electricity through boiler). Just it seems it is much warmer in your location, we get temperatures down to -30C Link to comment Share on other sites More sharing options...
ReedRichards Posted January 20, 2022 Share Posted January 20, 2022 3 hours ago, immortallt said: ... it seems it is much warmer in your location, we get temperatures down to -30C Indeed; typically we might only see temperatures as low as - 3 C on a few nights each year. Link to comment Share on other sites More sharing options...
shark Posted January 25, 2022 Share Posted January 25, 2022 On 07/03/2021 at 23:25, Chris Bottomley said: [...] 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. [...] @Chris Bottomley What metering equipment have you got installed for the MMSP and is it connected to the Therma V via PENKTH000? Our MCS installer is unfortunately not very clued up about MMSP but as we need metering for payment I wanted to get at correct meters installed and keep the option of joining the MMSP scheme in the future (once we find someone that is happy to sign a service agreement). Link to comment Share on other sites More sharing options...
markocosic Posted February 3, 2022 Share Posted February 3, 2022 What's the mmsp spec? District heading is my industry: Leccy meter with mbus £50 Heating/cooling meter with mbus £100 Gateway £250 Data service £3/meter/year Data sim £1/meter/year Mmsp should be easy enough! Link to comment Share on other sites More sharing options...
Chris Bottomley Posted February 8, 2022 Share Posted February 8, 2022 @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. Link to comment Share on other sites More sharing options...
ReedRichards Posted February 9, 2022 Share Posted February 9, 2022 8 hours ago, Chris Bottomley said: 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. Hold the Left Up arrow and the + button simultaneously for 3 seconds to enter the parameters settings menu. You can then set the number of cycles per hour ("2CR"), try 3 instead of the default 6. And the minimum on time ("3OT") - which unfortunately is limited to 5 minutes maximum but better than "a minute or so". https://livewell.honeywellhome.com/honeywell_wp/wp-content/uploads/Resideo_T3R_manual.pdf Link to comment Share on other sites More sharing options...
Chris Bottomley Posted February 9, 2022 Share Posted February 9, 2022 Quote Hold the Left Up arrow and the + button simultaneously for 3 seconds to enter the parameters settings menu. You can then set the number of cycles per hour ("2CR"), try 3 instead of the default 6. And the minimum on time ("3OT") - which unfortunately is limited to 5 minutes maximum but better than "a minute or so". https://livewell.honeywellhome.com/honeywell_wp/wp-content/uploads/Resideo_T3R_manual.pdf ReedRichards- thanks have tried that and will see if that improves operation. Link to comment Share on other sites More sharing options...
SteamyTea Posted February 10, 2022 Share Posted February 10, 2022 On 08/02/2022 at 22:57, Chris Bottomley said: 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 How do you grad the electrical data from the Smart Meter and PV. Link to comment Share on other sites More sharing options...
Chris Bottomley Posted February 14, 2022 Share Posted February 14, 2022 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. Link to comment Share on other sites More sharing options...
ReedRichards Posted February 14, 2022 Share Posted February 14, 2022 Does anyone use the Air and Water control option? I'm tempted to see what this does. I would have to set my third party controller to some high temperature so it loses control (except on/off). Link to comment Share on other sites More sharing options...
TonyP Posted February 17, 2022 Share Posted February 17, 2022 Therma V - minimising the water flow temperature My energy usage is very high (measured in kWh, rather than £s as obviously energy prices are crazy) as compared with my previous gas boiler heating system. Is it possible to reduce the flow temperature, since a lower flow temperature should improve the COP? I've spent many hours searching for information on this, but without success. My best guess is to select 'Auto/AI'. (The system had been set to 'Heat'). Then Auto will presumably lower the flow temperature whilst maintaining the desired room temperature. If so, what exactly do the AI values (which range from -5 to +5) do? What should be a starting value? (It seems to default to zero). If the room temperature is lower than the desired value, do I increase or decrease this AI value? Link to comment Share on other sites More sharing options...
ReedRichards Posted February 18, 2022 Share Posted February 18, 2022 "Auto/AI" is weather compensation. So it will tend to reduce the water flow temperature when the weather outside is warmer. This works because when it is warmer outside you house loses heat less quickly so can be heated less quickly also. The weather compensation parameters will have been set by your installer and can by changed if you access the installer settings. My installer was instructed to use very conservative settings. The ones I set myself are Outside Temperature: min -4 max 18 and Flow Temperature max 50 min 29. This means that the flow temperature will only be 50 C when the outside temperature is -4 C or less. -4 C is the temperature used for heat loss calculations on my MCS certificate (which assumes the flow temperature is 50 C). If, for example, the outside temperature is 10 C then the flow temperature will be about 37 C. The AI values add the set number of degrees to the calculated flow temperature. So if the calculated flow temperature was 37 C then AI +5 would make it 42 C and AI -5 would make it 32 C. Therefore in principle if the room temperature does not ever reach the desired value you should increase the AI number. However rather than flying blind I recommend that you check what values your weather compensation is using. Finally, your energy usage should be about 1/3 of the energy usage you would need to heat the same house with a gas boiler. But if you replaced an ordinary gas boiler with a heat pump and did not change all your radiators at the same time you would be likely to face the double whammy of very high heating costs yet not being able to keep the house warm enough. If you look back through all the posts on this thread you will find more information which may be of use. 1 Link to comment Share on other sites More sharing options...
TonyP Posted February 18, 2022 Share Posted February 18, 2022 Reed, Thanks - very useful, and pretty much as I expected. It's just so hard to locate all these in the installer settings, and then the exact meaning of each parameter is pretty obscure. However, when I change the User Settings from Heat to Auto the heat pump ceases to heat the house. I have a Honeywell Evohome controller, setting the on/off times and temperatures in 3 zones. Can I use Auto mode with this, or must I use the LG controller, which currently resides in the hot water cupboard, so is always very warm and would therefore will almost never ask for heat. Or, could the cause be the outside temperature thermometer was not installed or properly connected? In response to your comment about radiators: when we moved from the gas boiler to the heat pump we replaced all the double panel rads with triples, and all single panel with doubles, ensuring an oversize factor for heat output of between 3 to 4 (compared to the standard heat output value given by the rad manufacturer) in each room, so I'm hopeful the rads aren't the problem. Link to comment Share on other sites More sharing options...
ReedRichards Posted February 18, 2022 Share Posted February 18, 2022 I use Auto all the time with a third party controller and two zones so I see no reason why you should not be able to do that too. However if your heat pump is set to control by Air and Water rather that Water (as mine is) then your LG controller might possibly conclude it is hot enough already in the hot water cupboard (since I do't use that option I don't really know). A heat pump that could not accurately tell what the outside temperature is would get itself into all sorts of trouble so I doubt that that is your problem. The other way to proceed is to reduce the water temperature in the Heat setting and see how low it will go and still keep the house warm. You need to record the outside temperature and the water temperature and make a chart so you can construct your own weather compensation line. You should also look to see what your weather compensation settings actually are. Your radiators should be fine for the job. My installer used an over-size factor of 2.4 for 50 C output water flow. Link to comment Share on other sites More sharing options...
SteamyTea Posted February 18, 2022 Share Posted February 18, 2022 On 14/02/2022 at 10:06, Chris Bottomley said: 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. Is that on a Raspberry Pi. Saw a project online about it. Keep meaning to look into it more. I use an old CurrentCost with the optical pulse counter. Link to comment Share on other sites More sharing options...
paul_tanner Posted February 19, 2022 Share Posted February 19, 2022 Great topic, many thanks to all. Since we got our system 18 months ago we have had it on Heat mode with flow temp set to 40 C. However, I think we should be using Auto mode for outside temperature compensation. The remote controller was installed in a location where it will not be able to know the room temperature A 3rd party programmable thermostat is used to set the target air temperature and set it back during the night hours. The software version is 3.055a. In the installer menu I do not see anywhere to set the weather compensation curves (and I do not have a copy of the relevant installer manual). (The original installer is not local and is unresponsive.) I wonder if I the combination of a programmable thermostat and Auto mode is viable? If so I guess I'd need at least one more room sensor or move the remote controller to a better place. Any suggestions please? Link to comment Share on other sites More sharing options...
ReedRichards Posted February 19, 2022 Share Posted February 19, 2022 You only have to look back one page on this thread to see details (in a post by me) of how to change the Weather Compensation settings. I have a programmable thermostat and use Auto mode; there is no problem with that whatsoever. Auto mode does not need to know your room temperature . Link to comment Share on other sites More sharing options...
paul_tanner Posted February 20, 2022 Share Posted February 20, 2022 22 hours ago, ReedRichards said: You only have to look back one page on this thread to see details (in a post by me) of how to change the Weather Compensation settings. I have a programmable thermostat and use Auto mode; there is no problem with that whatsoever. Auto mode does not need to know your room temperature . Thx @ReedRichards Good to know that I can use both Auto mode and thermostat. I see above and in the user manual how to enable auto mode. If I do that I can no longer see what the flow temperature is - as I thought I could when using Heat mode. I don't think the compensation curves are set up and, as mentioned, I do not have doc on how to set them up. On a page above there is a video showing installer menus but evidently I have a different version. Link to comment Share on other sites More sharing options...
ReedRichards Posted February 25, 2022 Share Posted February 25, 2022 (edited) I thought I had commented but my comment has vanished (or I never completed it). You can see what the flow temperature IS in either mode by pressing the semi-circular arrow on the display. In AI mode you cannot see the target flow temperature and you can never see the outside temperature (from which you could calculate the target flow temperature). I would be surprised if you have a significantly different version of the software (go to Settings - Service - RMC Version Information to find out). But if so, ask your installer for an update next time you have the heat pump serviced. Edited February 25, 2022 by ReedRichards Extra comment Link to comment Share on other sites More sharing options...
Chris Bottomley Posted March 1, 2022 Share Posted March 1, 2022 On 18/02/2022 at 13:42, SteamyTea said: Is that on a Raspberry Pi. Saw a project online about it. Keep meaning to look into it more. I use an old CurrentCost with the optical pulse counter. 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. Link to comment Share on other sites More sharing options...
SteamyTea Posted March 1, 2022 Share Posted March 1, 2022 22 minutes ago, Chris Bottomley said: MMSP monitor Not got one of the as I only have storage heaters. Do you log electrical demand data? Link to comment Share on other sites More sharing options...
Chris Bottomley Posted March 2, 2022 Share Posted March 2, 2022 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. Link to comment Share on other sites More sharing options...
SteamyTea Posted March 2, 2022 Share Posted March 2, 2022 1 hour ago, Chris Bottomley said: Not sure what you mean by demand data, Your actual electricity demand, can be done as a total power draw or by individual devices. 1 hour ago, Chris Bottomley said: from its electrical usage data Is that in kWh, or just hours? Link to comment Share on other sites More sharing options...
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