The goal of the monitoring is to get it running well and save you money, so why spend £800 when £10 will do… A basic electricity CT meter won’t add much to that to give you better electricity input (esp tends to just report on compressor current and misses fans, pump, idle electronics etc).
Espaltherma will let you see all the behaviour and cycling and modulation you need to get it running well. It won’t be a truly reliable comparison to compare to others on the heatpumpmonitor site but then everyone’s house and situation is very different anyway.
I’m sure I’ve seen someone state a comparison between MID values and espaltherma somewhere and it was fairly close.
The DHW booster is normally just 13A resistive heater, so estimating that from the BSH on time is fairly straightforward, or you can adjust for the voltage if you have that value available, and measure resistance if you really want?
You’ve both made a very good job at putting it in perspective, thank you
I think I’ll do exactly that - go with ESPAltherma for now and see how I get on, although I’m sure I’ll curse myself if I end up going with the OEM kit later on as I assume the retrofit cost is significantly higher than having it installed with the pump.
In terms of cables between the pump and the ESP, I saw some people said they had used an Ethernet cable. Is this as simple as it sounds? Get an Ethernet cable, crimp the correct connectors on four of the wires (female dupont HP side, male ESP side if using M5StickC).
Is there a max length? I’d be tempted to ask them if they’d at least run an extra wire up to the airing cupboard as they will do for power to the cylinder anyway, unless that exceeds max lengths on the cabling. That way the ESP could live indoors. Otherwise I’ll just stick it in the outside consumer unit.
Would there be any value in running a separate Ethernet for the heat pump at the same time? I read something about a Daikin LAN module but I don’t really know the benefit of it.
I used some cat6 cable I had, it works.
Max length - it’s a serial cable, so maybe 10m to be safe?
M5Stick in case works ok if your WiFi signal is ok, otherwise in the cupboard might be better, because case is effectively a Faraday cage!
Daikin MMI only takes a WiFi adapter, if it’s Octopus they put one in anyway, there’s no Ethernet connection. It’s helpful because you can control your HP remotely using the Onecta app, via the Daikin cloud.
Had my 8kW Daikin installed on Thursday and have now got this running and logging. The ESPAltherma code has been updated for the M5StickC Plus 2. Got mine from RS as they seem out of stock everywhere else. I’ve not got a separate power meter so taking the data straight from the Daikin unit.
One question I have is why are there 2 fields for the current used (INV Primary Current and INV Secondary Current). It looks like everyone is using the Primary one for COP calculations. Why not the secondary one? Anyone know the difference?
I don’t recall if anyone here is using the ESPAltherma returned values for electricity power measurement. I think they are considered not very accurate, so most people are using some external measurement: a CT clamp hooked up to another device (an Eddi in my case) or another electricity meter like a Shelly
Which cable did you use to get the length? I am confused which wires and plugs I need to buy. I am hoping to use a M5StickCPlus2 when they are back in stock.
The EH connectors are stubby and if you try to crimp these remember you must leave the end exposed when crimping so as not to crush the connector (seen it a number of times).
Yeah the StickC uses 4 pins, but they’re not contiguous in a block of 8. I used a 2x5 & a 2x3 block connectors taped together with pins inserted to make it stable, I didn’t have an 8 way block.
The M5Stick, Ip68 enclosure and gland are all available from RS as well. All in stock now including the M5Stick (which despite the picture ships the latest model)
Another 9kW Altherma Octopus customer here, suspecting that the heat survey was Very Pessimistic and that our heat pump is…much larger than required. I’ve added a esp32altherma and installed a Emporia Vue2 whole home electricity monitoring system to look more closely at what’s going on.
A question for those that have already done this: where is the best location for signal strength inside the heat pump case? Even though I’m using a esp32 with an external antenna, I’m still only getting -88dBm to -95dBm signal strength, which isn’t great. I appreciate it’s sitting inside what amounts to a faraday cage…
I’m not going to modify the Altherma case in any way, so is there a location inside it that WiFi signals can more easily get in & out?
Hi Jonathon,
Welcome to the Daikin support / therapy group
Sorry, I’m not going to really answer your question but I figured it was better to get the ESP32 outside of the Althetma case, so I used some CAT5 to extend the DuPont cables and then fed the cable through one of the holes in the bottom of the unit.
The ESP32 is inside an external weatherproof box, which also contains my WiFi extender. Not the prettiest solution, but has been pretty reliable for 3 months now.
“…fed the cable through one of the holes in the bottom of the unit…”.
That might be my answer, except that I would look to get a (shielded if possible) aerial extension, so the esp32 could stay nicely protected inside while only the external antenna came out of the bottom of the air source unit and onto the top. #SilverDuctTapeForTheWin
I didn’t see any holes on the bottom of the Altherma case. Could I please have a hint where to look? (Thinking phone videoing & passing it around underneath to locate it).
If I’m understanding you correctly, that would involve drilling a hole through my external wall and running ethernet cabling through the house. Not going to happen in the short term. (Building a cat6a network is part of a future home renovation plan).
So for now I’ve ordered a double shielded 5m SMA Extension cable. https://amzn.eu/d/1g6rpt1 Yes, it’s longer than I need, but gives flexibility (and I couldn’t find anything shorter suitable priced ). I’ll play “hunt-the-opening-in-the-bottom-of-tye-case” when it arrives.
Separately, I’m a little… suprised at the lack of insulation on the large copper pipes in the Altherma 9kW. There’s a few bits of insulation here and there, but the lack of insulation on metal pipes in a metal box can’t be good for efficiency. It’s basically seems to be heating the great outdoors at our expense. :-\ Odd, given the careful attention paid to insulation in modern building techniques.
@EnergyExplorer You won’t hunt for long - the cover has space behind it, and around the frame to the left of the front opening. My cable just runs down from the X10A socket, towards the left, across the PCBs and out through the space, then loops back under the HP case towards the back and across to the box on the wall that holds my M5Stick. Not sure where you plan to put the external antenna, but it would work well on the top of the case to increase its effective power.
