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(@kev-m)
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5562 kWhs
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@ajdunlop 

What Derek said, and this:

I'm not sure why you get a spike after setback; if you look at my graph it ramps up the power very progressively.  I set my house to 21 and it always goes up to 1, occasionally 1.5 deg over.  Never falls below target though. And mine goes right down to its minimum and doesn't cycle. 

What is your thermo diff adjust set to?  From what others have said, this limits the variation from the WC target flow for the current ambient.  It looks like your flow temp limit is stopping the ASHP before your target is met.  A higher target and/or bigger thermo diff might stop it doing this when it's warmer outside.  Of course, that might not use less energy as the flow temp will go up. 

Screenshot 2023 02 21 19.24.16
This post was modified 1 year ago by Kev M

   
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(@gotaashp)
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This thread has some detailed conversations around the Ecodan's AA mode so thought I'd add some detail around a recent test in AA mode here.

I'm not sure I've seen anyone else(?) try this yet, but I wanted to see what happens when the 'thermo diff adjust' option is turned OFF.

In an attempt to understand how it behaves when off, I deliberately configured the flow temp range max value to 35C (the lowest configurable) and flow temp range min value to 25C.

Rather impressively I got a single cycle overnight that lasted some 4.5 hours (only stopped by the set temp at the thermostat hitting 1 degree higher).

MelcloudChart AAModeThermoDiffOFF 2

So far all sounds almost too good to be true, what gives? The flow temp range max value (35C) was completely ignored, and LWT wanted to get to 45C (which it appeared to hit and modulate lower a couple of times quite nicely). All in all I'd say I quite like it as it's the first time I've seen my Ecodan apparently modulate lower and hold it with success, however I could 'feel' the additional heat when the 45C peaks were hit (I'd prefer the heat to be a bit more even). Also what's the point of a configurable max limit if it's going to be ignored.

The above test was with the 'interval' set to 10 mins. I've repeated with it set to 60, it appears that results in a slower ramp up in the first hour, but ultimately it goes on to 45C. Also to note the curve is set to 38C at -5 (so I have no idea where 45C as an apparent target is coming from).


   
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(@kev-m)
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Posted by: @gotaashp

This thread has some detailed conversations around the Ecodan's AA mode so thought I'd add some detail around a recent test in AA mode here.

I'm not sure I've seen anyone else(?) try this yet, but I wanted to see what happens when the 'thermo diff adjust' option is turned OFF.

In an attempt to understand how it behaves when off, I deliberately configured the flow temp range max value to 35C (the lowest configurable) and flow temp range min value to 25C.

Rather impressively I got a single cycle overnight that lasted some 4.5 hours (only stopped by the set temp at the thermostat hitting 1 degree higher).

MelcloudChart AAModeThermoDiffOFF 2

So far all sounds almost too good to be true, what gives? The flow temp range max value (35C) was completely ignored, and LWT wanted to get to 45C (which it appeared to hit and modulate lower a couple of times quite nicely). All in all I'd say I quite like it as it's the first time I've seen my Ecodan apparently modulate lower and hold it with success, however I could 'feel' the additional heat when the 45C peaks were hit (I'd prefer the heat to be a bit more even). Also what's the point of a configurable max limit if it's going to be ignored.

The above test was with the 'interval' set to 10 mins. I've repeated with it set to 60, it appears that results in a slower ramp up in the first hour, but ultimately it goes on to 45C. Also to note the curve is set to 38C at -5 (so I have no idea where 45C as an apparent target is coming from).

It's hard to tell what's going on.  Like you say, where does the 45C come from? The way my AA works, it seems to be limited by the max value but that could be a co-incidence. 

I might try the same as you and see what happens.  But I'll have to think about whether I'm prepared to risk the consequences of a cold house if it goes wrong.  Mrs M is more sensitive to a drop in temperature than any thermometer I've come across! 

 


   
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(@derek-m)
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@kev-m

Hi Kev,

Didn't you buy her some wool and knitting needles for Christmas? 😋 


   
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(@gotaashp)
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Posted by: @kev-m

Like you say, where does the 45C come from? The way my AA works, it seems to be limited by the max value but that could be a co-incidence. 

H'mm I may well be looking for something that isn't there, but is this just a co-incidence I wonder...

45c

   
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(@gotaashp)
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Posts: 79
 

Posted by: @gotaashp

Posted by: @kev-m

Like you say, where does the 45C come from? The way my AA works, it seems to be limited by the max value but that could be a co-incidence. 

H'mm I may well be looking for something that isn't there, but is this just a co-incidence I wonder...

45c

I think I'm looking too hard, that's just the fixed flow temp default value so just a co-incidence. Just checked - my fixed flow was set at 36C.

 


   
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(@kev-m)
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Posted by: @derek-m

@kev-m

Hi Kev,

Didn't you buy her some wool and knitting needles for Christmas? 😋 

More than my life's worth!!

Anyway, I switched thermo diff adjust off last night so we'll see what happens.   

 


   
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 mjr
(@mjr)
Prominent Member Member
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Posts: 304
Topic starter  

It's possible that the AA program ignores low values as "broken" and starts its learning with a default value of 45 instead. We just don't know what's in their black box.


   
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(@ajdunlop)
Eminent Member Member
255 kWhs
Joined: 2 years ago
Posts: 17
 

I'm still trying to get my head around our office Ecodan 8.5kWh which is operating in Auto Adaptive mode using the main controller's thermostat.

Here is today so far as scraped from MelCloud using a script based on your excellent work @mjr :

image

There is a period from 06:00 to 09:00 where it looks like the HP is doing a very good job of a nice steady input of heat keeping the DT nice and even then it descends into its usual weird spikey behaviour. I can understand it cycling once it is nearing target temp and because the outdoor temperature has increased but why the big spikes in power and flow temp?

It has taken to nearly 13:00 today to hit the 21 degree target temperature.

Any thoughts about what is going on or could be ajdusted?

MelCloud's reported daily COPs vary considerably but are normally around the high 2.somethings. Although I guess this is a huge estimate if it isn't linked to proper energy meters.

Things to note (I am repeating earlier posts to bring all the information together):

  • I don't have the Energy Monitoring pack for MelCloud so the best I have is adding a multiplier to the compressor frequency value.
  • The night / weekend setback is 19 degrees and the daytime target temperature is 21 degrees from 08:00.
  • MelCloud is used to get between setback and target temperatures in 0.5 degree increases every 45mins from 05:45 (I turned this off a few weeks ago and just went straight to target in the morning but this resulted in huge spikes in energy when the target temp kicked in each morning).
  • Interval is set to 40mins.
  • The Thermo diff adj Upper Flow Limit is set to +5 and the Lower -1 (I found with the Lower limit reduced the HP would turn off for longer resulting in having to put lots of energy in at the start of the next cycle) 
  • System is all K3 rads.
  • Suspect the HP may be oversized.

   
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(@walkers-heatpump)
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Joined: 1 year ago
Posts: 23
 

Hi all. 

We had an Ecodan 6kw installed at the end of March and been trying to tweak it to run as efficiently as we can. I've been using autoadapt and had the same experience as others - it initially ramps up to the mid 40's and then stutters down to a better flow temp. I seem to be getting decent COPs (3.4 so far) but feel it could do better. 

What's been the key learning from it all? From what I can see it's:

- Increase the interval, potentially as high as 60mins

- Have smaller temperature changes from setbacks (?) I've just changed mine to half degree changes now every hour from 3:30am

- Make sure weather curve is set right and max flow temp - initially mine was shooting up to 50°, I've sorted that now with a 45° max and 43° at -2° curve. 

- Does the thermo diff adjustments make any difference? It doesn't feel like they affect it, I put a max of 3° over and it ran 6° or so to ver the curve point. I didn wonder if it delayed restarts on cycles though when using the minus adjustment

 

 

 

 

 

 

 

 

 

 

 


   
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(@steevjo)
Trusted Member Member
278 kWhs
Joined: 1 year ago
Posts: 42
 

Our experience with auto adaption has been and is good - 14kW Zubadan installed Nov 21.

BCBF4B05 AD82 4CA0 A852 195AF805F7BA

image shows last couple of days flow temp, room temp, outside temp and house power consumption. Data collected from MelCloud via Home Assistant MelCloud Integration, power from Powerwall again by HA integration.

Not seeing any of the less than optimal behaviour discussed in this thread - AFAIK all the settings discussed here have never been touched. Room temp profile is 17 C overnight, 18 during the day and 20C from 1600 - set in the FTC controller.

It’s not perfect - AA does let the room temperature rise above the set temp by about a degree before turning off heat pump - this could be a comfort thing, better to keep trickling in heat than switching off. It also takes a very leisurely attitude to warming things up in the evening - can take a couple of hours or more. It also seems to take 10 mins to react to temp profile changes. In general though pretty happy.

Has anyone tried speaking to Mitsubishi tech support. I’ve found them open and friendly when I have called - bit of a struggle to get put through to a techie, persist!

Good luck

Our experiences with solar pv, ASHP, battery, and EV: ourhomeelectric.co.uk


   
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(@walkers-heatpump)
Trusted Member Member
237 kWhs
Joined: 1 year ago
Posts: 23
 

I've not tampered with it for a few days and I feel like it's learning better without my interference, better at dropping flow temps and sticking to it so I'll give it a break for a while! It still seems a bit too alike my old boiler tho! On the auto setting, my old boiler would crank up to the max and then modulate down from there - that's what it feels like on auto-adapt at the mo, it spends best part of an hour getting up to 45°, before cycling and modulating to the flow temp it should be (or closer anyway)

I also get it going a degree over target temp - which again feels a bit too much like boiler boom and bust. It's tricky setting a temp because 20° is about right for us but 21° feels too warm - so we set to 19° knowing it will get up to 20° however we then have to wait for it to get down to 19° before it kicks in again


   
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