Renewable Heating Hub Heat Pump Forums

Search with Wattson
Forums
Renewable Heating
Air Source Heat Pum...
Mitsubishi Ecodan S...
 
Notifications
Clear all

Joining the Renewable Heating Hub forums is completely free and only takes a minute. By registering you’ll be able to ask questions, join discussions, follow topics you’re interested in, bookmark useful threads and receive notifications when someone replies. Non-registered members also do not have access to our AI features. When choosing your username, please note that it cannot be changed later, so we recommend avoiding brand or product names. Before registering, please take a moment to read the Forum Rules & Terms of Use so we can keep the community helpful, respectful and informative for everyone. Thanks for joining!

Mitsubishi Ecodan Stats Reporting - Accuracy Worsens In Auto-Adaptation Mode

 
Page 4 / 4
Air Source Heat Pumps (ASHPs)
Last Post by cathodeRay 2 months ago
38 Posts
5 Users
3 Reactions
2,299 Views
RSS
 Ecoste
(@ecoste)
Eminent Member Member
Joined: 7 months ago
Posts: 41
23/03/2026 5:50 pm  

@sheriff-fatman Thank you for the additional information. Your system seems to be very similar to mine and it produces very similar results. I have used the data from the Ecodan system as my measure of performance, this is provided by Mitsubishi and is their data not something that I have put together. The data for the heat pump specifies a COP of about 5 at 7C, you and I are achieving about 3, that's a big difference. I don't think that there is anything about routing the pipework that should impact the COP. I have had 4 visits from Mitsubishi, they have accepted that the COP is poor and have noted that the data provided is for specific laboratory conditions which are not met by a standard installation.

 



   
ReplyQuote
cathodeRay
 cathodeRay
(@cathoderay)
Famed Member Moderator
Joined: 4 years ago
Posts: 2939
23/03/2026 8:36 pm  

Posted by: @sheriff-fatman
↑

Whether or not it turns out to be statistically significant is another matter, but it's a good visual to show the difference between the two operating modes that caused me to post the findings.

...

I hadn't really studied the above graphs when I posted them, but the data within them is actually quite interesting.

That's why I like charts. The human brain can assimilate information very quickly from images. As I mentioned earlier, the easiest way to check whether the samples are statistically different is to plot the 95% confidence intervals for the regression line and checking whether they overlap or not. This can be done both in R and in python. Here's my infamous 2025 setback vs no setback energy in vs OAT data plotted in R with 95% confidence intervals:

 

image

 

It appears to show the daily energy use is significantly lower when running a setback, at least at lower OATS, but I think the data may be biased. For a start, spring is not the same as Autumn and winter. Other unknown unknowns could also be in play. This in turn led me to the idea of using 'matched pairs' ie match setback days to non-setback days where the variables we do know about are matched. For a start, that means from the same season. I already have the Spring 2025 data, which was a period of setback running, and I am still collecting this Spring's data, which is a period on non-setback running. Once I have all the data (around about the end of April) I will do the plots and see what appears.

 


Midea 14kW (for now...) ASHP heating both building and DHW


   
👍
2
ReplyQuote
Page 4 / 4
Forum Jump:
  Previous Topic
Next Topic  
Share:

Join Us!

Directory

Latest Posts

Click to access the login or register cheese
Protected By
Shield Security PRO