Hi. My first time on the forum. Please bear with me.
We had a Daikin Altherma 3 H HT W 18kW installed in Dec-2022. We’ve had a lot of problems with it so now we (the consumers) are trying to figure out COP and SCOP to see if its working within the range its supposed to.
In the information section on the ASHP menu, under Energy Data, Energy Input the figure since installation is 854576 kWh. Can that be right? It’s only been installed for 26 months.
Hi @matiga23.
Are you sure there isn’t a decimal point two digits from the right?
I could certainly believe ~8500kWh over that time period for an 18kW unit.
Sarah
Welcome @matiga23
No, it can’t be right.
854,576kWh across 26 months would mean running at an average of 45kW of input electricity. That’s far more than your heat pump is rated for / able to draw even running at maximum. In fact its at least double what you main house fuse will be rated for.
@SarahH suggestion of 8,545.76 is most likely.
The Daikin MMI doesn’t display decimal places so it can’t be as simple as you have misread it, there must be a mis-configuration.
If you go into the Energy Data and look at it in the graph, month by month, do you see high usage in the winter months and low usage in the summer months? You can also check this out on the Onecta mobile app by going to Insights > Clime Control > Year and then looking at 2024.
If you see the high winter, low summer then the unit is probably producing correct data, but off by a factor of 100. There is a setting for this which can be changed. If winter and summer usage is similar then there is probably a bigger problem.
The final thing that would be useful to know is what is the figure for total produced heat from the Daikin MMI Energy menu?
Hi.
Thank you both for your replies.
There’s no decimal point - I’ve looked at the number disbelievingly many times.
Had a look at the Energy Data and there’s something strange on the month by month screen. Last February (2024) the energy usage is 840060. We had two incidents last February, both EA-01 errors, and were without heat and hot water for 21 days. A Daikin engineer came and fixed the errors. I wonder if, in one of those visits, they did something to the data/settings?
Total produced heat is 48084 kWh.
We don’t have app access to the Daikin - an oversight by the installers and quite annoying!
Hi again.
That looks likely to be the problem - the Feb2024 is erroneous. If you subtract that figure from the reported total-to-date you get about 14500kWh, which gives a very plausible SCoP of 3.3 based on your energy produced figure.
I would simply discount the Feb2024 figures (produced as well as consumed), and make your CoP/SCoP calculations based on all the other months.
Thank you SarahH.
Is that possible? That erronous data can be inputted into the system?
I doubt the massive reading is caused by the Daikin technician entering data, its much more likely the system was getting incorrect readings before/during the failure that gave the EA-01 code. EA01 isn’t mentioned in the manual for my system (a different Daikin Altherma) but error codes in around that area indicate over-voltage or circuit board failure.