@andy_e I requested OE to do a survey but in the end did not have an install from them as my job was ‘out of scope’ as they put it. I did have the same Daikin heat pump that OE would have used. At the time of installation, the Homely integration had not been completed for the Daikin model and so this was fitted by my installer some 7-8 months later.

I should mention that Octopus engineers (a plumber and an electrician) spent 3 hours with me carrying out the survey - very thorough and they were happy to explain everything and answered all my questions.

It was a shame that my requirements didn’t fall within their ‘scope’ as it was then and they did explain that, as their training evolved (it was very early days of them starting to install heat pumps then) they would be able to accommodate a wider range of installations, but that time might be some way away. I really felt they knew their subjects, that they worked as a team and was confident that they were competent. 

Homely supply to registered installers (there are training materials for this on their website) though the actual installation is fairly basic and the kit comes with all the necessary parts and instructions in the package. There is a review I wrote on the RHH reviews pages. Regards, Toodles.

@toodles Thanks for this info. I will look into the Homey and maybe discuss with OE to see if it's something they can install for the additional cost. 
Thanks again for the information and reassurance that OE is a good option.  

@andy_e 😊 Toodles

@andy_e  I faced the exact same dilemma recently (there's a post somewhere about it). I initially opted for Aira, but on the install day within 30 minutes the install team discover 3 major issues their surveyor didn't pick up on so install was aborted on the same day. That was some months ago and the issues were specific to my house, not their equipment per se (eg they had forgotten to add the legs to height of the heat pump calculations so it wouldnt fit under the window, and some cable runs through the house that would have been ugly, and the proposed pipe run didnt work). 

After that I opted for Octopus and they installed the Daikin Altherma 8kw 3 weeks ago. Ps the Daikin generally is seen as a good unit from what I could see - EDIT: It is very UGLY though compared to Aira, why can Daikin not get a designer in!. We required 3 surveys in the end (last one on the back of the failed Aira install as they then also wanted to double check, and indeed the pipe run needed more thought than the first 2 surveys indicated).

The install went brilliantly, the team really care and the unit is working great. I had to have Octopus come round to do some tweaking, the after service was excellent too. The price difference was quite so that's a bonus too. I don't think anyone could've done a better job. Very pleased I want down that route.

@pie_eater Again, some great info relating to my OE and AIRA drama - I really appreciate the detail, and it's gone a long way to allaying my concerns.  I am progressing with OE and have told AIRA I am cancelling.  Now going to planning so lets see how this goes!

@andy_e I hope it all goes well and smoothly - please keep us up to date (We need to know these things!😉) Toodles.

@andy_e 

I'll be interested to see how you get on. I was originally going with Octopus with a 12kW Daikin. Once the planning permission because of noise issue arose their support was dreadful, no solutions were proffered, and I eventually lost patience with them and got my £500 survey fee back. I then had two more surveys done, interestingly both recommended an 8kW unit, with one of the surveyors shaking his head when I told him Octopus had said I needed the 12KW unit and explaining how his calculations had been done on his iPad. 

I went with Aira, yes more expensive but they replaced all but one of the 25 year old+ radiators and for me there is a big piece of mind in the 15 year parts and labour guarantee.

Also notable is if the Octopus Daikin unit was the same dimensions (as narrow in particular) as the good looking Aira unit the noise issue would not have arisen

Octopus's heat loss calculation is very cautious. They told me my heat loss was about 13.5kw, so 'out of scope' for them, when my own heat loss calculation mirrored Aira's at just below 8kw. If you have walls of varying insulation values in a room, Octopus selects the worst value to use for the whole room. I think even Aira's heat loss may turn out to be a bit cautious. I have my heat loss summary from Aira and they estimate that my annual Energy Demand could be 32695kWh. Over the last 2 years, my actual gas usage is aprox 16500kWh annually.     

Well, after doing a lot of research, reading, watching, listening and help from this great forum, we attended the Aira Open Day at their Urmston office on Saturday 16 November. It was a really useful session, and got to see the actual products. We arranged an initial visit/assessment session for this afternoon. The assessment was fine, as I had prepared quite a lot, and the great news is that we agreed on the likely size and shape of the solution - 6kW Aira ASHP with 100l indoor unit and their 40l buffer tank. Radiators to be replaced were 6. For perspective, we are two people in a 1948 semi, with 79 m2 floor area, insulated cavity wall, double glazing all round. We have no bath, only a shower and annual gas estimate of 5000kWh. 
So we have agreed and paid for the next step: the detailed survey and heat loss calculation leading to the detailed design, which they underwrite with the 15 year comfort guarantee. That was £99.  

Hi MikeH - I’m a newbie on the site and we’ve just had our Aira heat pump installed last week.

I have a question on your post if you don’t mind. As I can’t seem to locate any information on similar sized properties, I have a feeling our pump is working way too hard right now, we’re a 3 bed semi with an 8kw. I wondered if you’d know what kind of kw usage per day would be seen as normal?

Welcome to the forum, you will find that people here are very willing to help.

To answer this properly we need to know a bit more eg what was the assessed loss of your house and at what outside air temperature.  We would also need to know the current or design flow temperature and roughly where you are/outside air temperature.

However as a very, very, very rough ballpark: My house (currently on gas, heat pump to be fitted next week), has a measured heat loss of 7-7.5kW at -2C.  Its currently running at about 5kW, 24x7, so about 120kWh per day.  That's energy to house.  I'm in the South East of England so its around freezing, a bit above during the day.

At the current temperatures you would expect a heat pump to be running at a COP of 2-3 depending on the flow temperature you are operating at and where in the country you are.   So a heat pump heating my house would be expected to consume something between  40 and 60kWh per day.

My figure includes DHW but we get some from solar (today particularly - in fact we were dumping to the EV at one point) and anyway don't use a lot of DHW.  At a COP of 2, 200l of DHW roughly adds another 5kWh to the consumption.

Obviously consumption will drop when more normal temperatures return, both because the house will lose less heat and you will be getting a better COP (assuming weather compensation is correctly adjusted).

Hope that helps, feel free to provide some more info for a better estimate.

Hi @m1308  as JamesPa said there are many variables but yes we have the Aira 8kW in a 3 bed,but ours is a detached Victorian property. We are about 113 square meters so if you know your property size that my help. This is our usage this week as the temperature dropped. Yesterday was high of 3 low of -1'C. Its lower temps today (Wednesdays).  Monday was an anomaly because I believe it ran a scheduled legionella cycle which took a while and used a fair amount of energy. If you have historic daily energy usage from a smart meter you could do what I did. Find a website with historic temperature data for your area from last Nov, find I similar day and match it to your old gas usage for the save day. On a day similar to yesterday my old gas boiler used 120kW were the heat pump used 43KW.