Posted by: @hughf

It’s not like a combustion appliance that might gas you to death. It’s a fridge, in your garden.

But it is also a fairly expensive fridge sat in your garden and a relatively small extra expense (I've been quoted £80 for our ecodan) hopefully to keep it running sweetly for longer before you have to buy another one.

Hi Julian,

How did the service go?

Interested to see a service check list if they had one. Thanks

Adam

@adam-c Afternoon. I was pleased with the service. Daikin chap was with us 1.5 hrs. I am waiting for the checklist report. 
He reviewed the installation and said it met Daikin standards. 
He did say I’d overpaid on the gold level contract as I have a 5 year parts and labour warranty. So I will step down at December to save a few quid for 4 years. 
He did switch on the legionella setting for the dhw, which now thinking about it, was unnecessary. With my diverter from solar PV, cylinder gets to v hot temps. Never had a legionella setting on the oil boiler. So I will switch off. 
I will report again when the checklist comes through 

Posted by: @julianc

@adam-c Afternoon. I was pleased with the service. Daikin chap was with us 1.5 hrs. I am waiting for the checklist report. 
He reviewed the installation and said it met Daikin standards. 
He did say I’d overpaid on the gold level contract as I have a 5 year parts and labour warranty. So I will step down at December to save a few quid for 4 years. 
He did switch on the legionella setting for the dhw, which now thinking about it, was unnecessary. With my diverter from solar PV, cylinder gets to v hot temps. Never had a legionella setting on the oil boiler. So I will switch off. 
I will report again when the checklist comes through 

Hey Julian,

Do you have an update yet for the last 6 months with the Daikin controller in comparison to last year with the Nest?

@watto my Daikin has been effectively switched off since May to September, as my h/w is heated via solar PV and a solic 200 diverter to the immersion.  The Daikin uses 1kWh ish per day just to keep it ticking over.  We turned the heating on at the ned of September, but it has only been running a bit.  Although I have switched on Daikin weather compensation, the on/off still seems to be controlled via the Nest.  So I need to talk to Daikin at ask how to switch it out of the circuit.

My current SCOP numbers are:  3.18 over the summer. (A lot of this energy will be solar PV).  April 21 to 22 my SCOP was 3.78.  So good, but I am trying to get to 4

@julianc

Try turning up your Nest to remove it from control.

During Spring and Autumn you will still probably get some cycling even on weather control, because the heat pump cannot pull back below minimum setting, but still produces too much heat energy.

Great thread, thinking of swapping my Gas boiler for the Daikin Altherma has anyone integrated the Daikin into Home Assistant? https://github.com/tadasdanielius/daikin_altherma

I have Tado TRV's also, I may be able to call for heat from the Daikin based on per room temp, rather than programmed schedules....and also heat the DHW tank based on temps…

Hi Julian/All,

Stumbled upon this and was inspired to write my first blog post ever.

I live in an urban town area and looking to acheive the same with minimum impact on neighbours. My conclusions so far.

1. 3kw solar system - maxeon or project solar (open for recommendations as I can only fit 8 panels on the roof) with iboost once batter is full

2. Givenergy hybrid inverter and 9.6kwh system (seems like best plug and play with AI to take advantage of economy 7/octopus go)

3. Daikin altherm 3 h h t 18kwh model due to its 38 decibels at standard mode (can't find anything that can match that, even the newer samsung model)

4. Mixergy tank - I'm think of this based on posts and it would be useful to heat smaller amounts of water in winter months.

House is renovation and insulated up to the hilt with triple glazing , large radiators and heat recovery on ventilation. 

Aim is to be mostly off grid in summer and use overnight economy 7 in winter only. 

Big question I have is would the above spec acheive this? And how would I set up the control system to only draw power from battery before going to grid?

My assumption is I heat the house overnight from ashp in winter at the same time as charging battery to full. 10kwh should then be sufficient ish to get to 11.30 when cheaper tariffs kick in. 

All info, help, insights greatly appreciated.

Best

Pat

@p-c-brown there is no chance you'll make it through the winter on economy 7 with 9.6kwh of storage. You'll only be able to use around 8kwh of that and the ASHP will gobble that up in no time. Your bills will be reduced for sure, but you won't be able to avoid peak power without bigger storage

Posted by: @p-c-brown

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Hi Julian/All,

Stumbled upon this and was inspired to write my first blog post ever.

I live in an urban town area and looking to acheive the same with minimum impact on neighbours. My conclusions so far.

1. 3kw solar system - maxeon or project solar (open for recommendations as I can only fit 8 panels on the roof) with iboost once batter is full

2. Givenergy hybrid inverter and 9.6kwh system (seems like best plug and play with AI to take advantage of economy 7/octopus go)

3. Daikin altherm 3 h h t 18kwh model due to its 38 decibels at standard mode (can't find anything that can match that, even the newer samsung model)

4. Mixergy tank - I'm think of this based on posts and it would be useful to heat smaller amounts of water in winter months.

House is renovation and insulated up to the hilt with triple glazing , large radiators and heat recovery on ventilation. 

Aim is to be mostly off grid in summer and use overnight economy 7 in winter only. 

Big question I have is would the above spec acheive this? And how would I set up the control system to only draw power from battery before going to grid?

My assumption is I heat the house overnight from ashp in winter at the same time as charging battery to full. 10kwh should then be sufficient ish to get to 11.30 when cheaper tariffs kick in. 

All info, help, insights greatly appreciated.

Best

Pat

The size of heat pump should be based upon the heat loss of your home, not which model is the quietest.

What is the heat loss?

Hi Pat!

We have a tiny 2.5kW(thermal, 660W elec) gshp, 4kWp solar, MVHR, 150mm EWI, 30kWh V2G car, 200l DHW tank, 4 bed highly insulated retrofit house, 4 people in it - not that far from what you're thinking of. 

My thoughts are:

If you need an 18kW ashp, then you will likely use a lot more than 10kWh of electricity during the day in winter.  We use 20kWh; 10 of those for laptops, telly, tea, coffee, fridge, another 10 for the heatpump typically.  The max we've used is I think 25kWh in a 20 hour window - and I would expect you to use quite a bit more unless your heatpump is hugely oversized.   Can you increase the size of the givenergy storage later?  If you stay with Octopus Go, it is only a 4 hour window - you'll want to fill the battery from flat to full in that 4 hours somehow. 

Do you have a peak heatloss figure, or a yearly heat demand figure?

Our solar is almost useless in winter - it gets horribly shaded.  Maybe 2kWh / day average winter, 20kWh/day average in summer.

In general I like the mixergy technology - but I think it is better suited to a gas/oil boiler than a heatpump.  I say this, as the inlet to a mixergy tank is at the top - always at the highest temperature, so always at the worst COP.  In contrast, a conventional DHW tank inlet is at the bottom - so the COP slowly falls from 4 down to 2 as the tank is heated.  I expect then that the DHW bill will be greater with a mixergy tank than a conventional one, for the same use pattern -if anyone has seen a study on this, it would be interesting.  We heat our DHW to 46degC by the heatpump during the "go" period, and for the last 30mins of "go" the immersion turns on.

@p-c-brown glad you enjoyed my thread. Derek’s point below is correct. Need to understand heat loss and heat demand before picking an ASHP version or model. However noise is an important consideration. But there are different sized Altherma 3H HT machines. 
Have you or potential installers undertaken heat loss analysis?

I can’t really comment on the “off-grid” idea. It’s seems ideal, but unlikely as when it’s -8C outside in December 22, my system was using 45kWh per day. Only for a couple of days. But even so. 
Good luck with your ongoing research and any questions, please ask.