Sorry to jump on this thread with my own question, but I've had a technical survey from Octopus and AIRA. I am now at a point where I need to decide. On paper, it feels like a no-brainer, but for some reason, I can't decide between the two.

Heat Loss for the relatively new build is about 3.5 kW.

Octopus Quote: £620... For the Daikin Altherma Monobloc - 4kW (R32 2022 Release) (EDLA04E2V3), a 180L Cylinder (in the loft), 4 new Rads and a years servicing thrown in (5yr Warranty).  I will need planning permission due to noise coming in at 43db versus 42db requirement...

AIRA Quote £6000...  Using their new (yet to be fitted in the UK) hydro box, they will fit the system into the current cylinder cupboard with the 'brains in the loft', propose 8 new rads, and offer a 15-year warranty.

Does anyone have experience with the Daikin Altherma? Is it £5400 worse than the Aira solution?

Because bizarrely, I am still drawn to the AIRA, and I do not know why (Maybe it's because it looks prettier).

Cheers Andy

@andy_e We have a Daikin EDLA08 and are very happy with the performance, efficiency, noise level and controlability via a Homely smart controller. The unit was installed in February 2023 and we had an annual service carried out by Daikin themselves in March this year. Very happy with the set up though we don’t have space for a DHW tank so our water is heated by a Sunamp Thermino ePV210 using solar or grid via a Myenergi Eddi.
Can’t compare with the Aira unit as I have no experience, but I can say that I think Octopus will look after you well with their installation if you go for it. Regards, Toodles.

@toodles Thank you for getting back to me so quickly. I've been a regular lurker on these forums and appreciate your opinion.

I think this may be the little push I need to make the sensible decision. I didn't mention it, but the AIRA route would have impacted my ability to go for solar, too. Now, I am convinced I'll push forward with Octopus and get me a roof full of solar, too.  

My next problem (for a different thread will be the Tesla Powerwall 3 or an alternative... 🤔).

Andy

Posted by: @andy_e

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Tesla Powerwall 3

You may want to check the business case for this.  Personally I can't get the business cas for a battery to work and the environmental argument is, so far as we have been able to tell on this forum, weak.

That said many are very satisfied with their batteries.

I would definitely suggest solar first though, not least because PV installers seem to make their margins on batteries, so if you already have one when you go to get solar you may find options restricted.

@andy_e That's quite a price difference. Octopus would not honour our quote of £4500 due to their heat loss calculation saying the heat loss was out of scope. So Aira's final price of £6100 was the next best price. I would have struggled to not accept Octopus if they would do it for £620. Quite a few less radiator changes though. I assume Octopus are designing to 50'c flow temp in comparison to Aira designing to 45'c? Aira would be fitting their smallest 6kW unit which may be a tad oversized for your heat loss. So I'd not assume the Aira would be cheaper to run and claw back savings over time. Are you also £500 out of pocket at this stage if you pull out of the Octopus install. I do like the look of my Aira unit but from where it's located I could literally not see it until spring If I wanted too. So do think how much you like the look of it and how much will you see it from the house.     

@jamespa Thanks for the response- I’ll do some additional digging before pressing the button on that large investment for sure!

@mikeh 
I’ve hit go on Octopus as the cost difference was massive - did like the look of the AIRA but not £5400 much.
Just put both proposals in the spreadsheet and Octopus have stated a flow temp of 50degress versus 45 with AIRA also like you mention the AIRA is 6kw v the 4kw from Octopus (Aira seems oversized and really not experienced enough to know how they’d perform side by side given the perceived ‘smarts’ with AIRA?).
Re the Rads AIRA were replacing 8 and Octopus 4 so not a massive difference and am now discussing with Octopus for additional rads (for more money of course).
 
Again thanks for the views and opinions - I’ve been stuck in a loop for weeks!
 
One final thing @toodles was the Homey something you had installed during the Octopus install or was it done post initial installation? Is is something I’d need a heating engineer to do? Or something a reasonable handy (completely uncertified) person could do?

@andy_e My Aira installation finally works quite well seemingly. However, the control (their app) is still very basic. It seems that established brands (like Daikin, Vaillant, etc.) have a lot of options for data monitoring and automation, if you're into those things. Re Aira, it's more of a set-and-forget system, and hope for the best 🙂

Posted by: @mikeh

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@andy_e ...Aira would be fitting their smallest 6kW unit which may be a tad oversized for your heat loss. So I'd not assume the Aira would be cheaper to run and claw back savings over time. ...

@trungdong I feel better now that the app shows energy consumption data. You can figure out roughly how it cycles from this. As we don't have COP data, I have been using energy usage to see if performance in similar to others heat pumps. I have found a similar sized house on open energy monitor that is a similar size with a similar sized heat pump. Most days we are about 1kwh above or below them and running similar flow temps (I've put temp probes on my buffer) They have decent COP when it's running so I'm happy enough.

@ivanopinion Heat pumps really should have labels standardised. IMHO if says 8kw on the model lable, it should hit 8kw at a standardised flow temp (maybe 45'c) no more no less.

Posted by: @mikeh

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@ivanopinion Heat pumps really should have labels standardised. IMHO if says 8kw on the model lable, it should hit 8kw at a standardised flow temp (maybe 45'c) no more no less.