October and November update 

So my Daikin has had a good October and November (as at 16th). 
October SCOP was 3.87  Consumed 10.4kWh/day compared to predicted 13.8kWh/day

November SCOP was 4.06  Consumed 15.5kWh/day compared to predicted 31.6kWh/day

Good news. Happy ASHP owner. If you read back, I’m using weather compensation curve, with the Nest acting as a step up switch. 

My January SCOP was 3.97 or 30.52kWh/day. 
February SCOP was 4.46 or 16.48kWh/day

This is running weather compensation. With Nest control gradually increasing temperature during the day. H/w cycle is overnight on cheaper electricity.

I’m pleased with this performance. 

@julianc Likewise with my Daikin with Homely controller; figure of 3.8 to something over 5.5 ain’t bad as far as I am concerned! Regards, Toodles.

We used 8,891kWh of electricity in 2023. At face value this seems a big number. But that is all our energy usage. No gas or oil. And all the electricity for our EVs. So no petrol costs. 
Octopus Go tariff. 
And it’s roughly split 2/3rds at 29p & 1/3rd at 9p/kWh. Total cost £2000. 
And we have 4kW of solar PV from 2012 which generates about 3500kWh of electricity for which we are paid about £2k. So break even. 
We always try to undertake the Octopus electricity savings opportunities. There is an 1/2hr one tonight that will pay back. 
And I’m still waiting for Vehicle to Grid charging, so I can use my EV batteries to run the house during the day and charge them up on cheaper electricity overnight. 

Keep looking for ways to reduce my CO2 footprint. As Shaw Taylor used to say “keep ‘em peeled” 

Greetings RHH. Not posted for a while. Here are the scores from the Worcestershire ASHP.

At the end of the 3rd full year we achieved a SCOP of 4 using the Daikin weather compensation curve.  And some Nest control still in place. So we start at 8am at 18.5C. Raise to 19.5C at 5pm and then 20C at 7:30pm. Set back to 15.5C at 10:30pm or 11:30pm on a Friday & Saturday night. 
We are pleased. 

But I continue to seek improvements. Alex & Henri of Havenwise got in touch with me via X (twitter) to ask if I’d be interested in trialling their algorithm solution?  It works for all boiler types but were seeking some ASHP tests. 
Fantastic chaps with some government seed funding they are looking to improve ASHP efficiency and reduce costs thru time of day tariffs. 
So far, things are going well. We had to fit the Daikin internet gateway (a test in itself as Daikin seemed to offer a different answer as to what parts were required depending on the time you called tech support). Once sorted, they also supplied a Govee internet thermometer. I had to switch off the weather compensation curve and set the Nest to 23C. 
Havenwise took control nearly 3 weeks ago. After the first couple of weeks the COP was 4.35. Recently it hit 4.77 for 4 days as they tune the algorithm. Recent colder weather has reduced the COP to 4.5. Noting this is short term and a COP, not a SCOP, I’m still pleased with efficiency progress. I think I need to switch to Agile Octopus Go for better time of day tariffs. 
Currently only issue is the hot water which I used to heat overnight but there is some “interference” and it’s taking a lot longer to completely heat. This is included in the COP however. 
I will continue to report back. 

@julianc thanks for the update and good to hear from you again. It certainly has been a while. Interesting to hear about your HavenWise experience. Henri (@hcas) is active on the forums.

Havenwise continues to provide improved COP for my Daikin ASHP. 
Impressive. 
Achieved a COP of 3.73 over past 26 days. Used 36.5kWh / day during this quite cold weather. 
This compares to a predicted 54kWh / day. 
How have others been doing during January?

@julianc so far in January we’ve achieved 3.8 energy efficiency. Really pleased but we’ve not not a calibrated heat meter only the Vaillant predictions so slightly suspicious still.

@judith very good. What are your property dimensions?  How many total kWh?

On a connected by slightly different topic, I’ve switched from Octopus Go to Intelligent Octopus. This gives me 6hrs from 11:30pm to 5:30am at 7p/kWh and 25p at the other times. But my Zappi mk1 EV charger (and hub) enables Octopus to control my EV charging. You enter the target % and time when you want it charged and Octopus determines a charge schedule. Which can be during the day. Not had a full month yet but our average price was 15.5p/kWh at a cost of £257 7th Dec to 6th Jan. seems ok. 

@julianc 190m2 and not done a full year yet on ashp. Annual gas usage ~17,000kWh but efficiency unknown. We’ve used the wood burner a similar number of times and have similar room temperature.

That makes our pump just enough in power (exactly what we wanted, since we need the excuse to use the wood burner occasionally) and from your info above yours is oversized. Have you calculated how much over? Based on that Havenwise is doing a great job.

Your average pricing on intelligent go is less than ours on cosy (18p last month) due to us needing a fair bit (20%) of std rate in cold weather when the battery has emptied. That’s useful input for future EV choice, assuming they keep a similar tariff structure.

@julianc 853 kWh so far for January and that is for 22.5 degrees C 24/7 (according to Onecta). Regards, Toodles.