New air source heat pump Qs

[NoNameNoNumber]

Evening all,

We're going to replace our aging oil boiler for an ASHP.
We have 6.7kW of solar PV and a 5.12kW/hr battery so it makes sense. I've gotten rid of all of the downstairs rads and having the flooring machined by JK flooring for a wet UFH.

I've received a number of quotes, all around the £7-7.5k mark with the BUS, after a little research I've ruled out any of the Samsung/LG units. Been looking at Daikin and Steibel Eltron.

When we had the PV done I was advised to look out for HEIS, MCS and Napit. Now who is the equivalent for ASHPs?

What assurances can I expect that we will be able to maintain >20ºC all winter and my COP will be >400% as per the manual?

Do I pay the installers £15k then claim the BUS myself or do they do all of that and I just pay out the £7.5k?

At the same time I want them to upgrade my inverter from 3.6kW to 5kW and sort the DNO (which a number of companies have offered to do) but they use the flexi orb cert. Will this have any effect on my export tariff and SEG with Octopus?

I'm sure there will be more...

Kind regards

 

[NoNameNoNumber]

Thank you all for your replies, and apologies for the delay, we bought a new-born home last week so it's been a little busy here...

We've had several quotes back now and have a technical survey with Aira next week.
They offer a 10 year performance guarantee, 10 year product and installation guarantee and a 2 year insurance backed by HIES
The 12kW Vailiant Arotherm @ 45ºC flow temp SCOP is 4.21. I'd like to see in writing that figure being backed by their performance guarantee.

 

[NoNameNoNumber]

£7500 after the BUS
That includes a 250l tank and 5 new rads
Also, a 5kW solar inverter (long story)

Aira are bringing their own ASHP to the market, think he said the 6kW and 8kW are out now but the bigger ones are due Sep. They have a 15yr warranty, and a SCOP of 4.7 @35ºC which isn't as groundbreaking as their sales guy tried to convey. They do only make 57dB though, and the warranty is good. He did say they're based on the Arotherm.

The Aira Heat Pump Outdoor Unit | Aira

The Aira Outdoor Unit efficiently draws in and extracts thermal energy from the fresh air outside to heat your home and hot water.

www.airahome.com

 

[NoNameNoNumber]

I asked their tech guy when they were round for a full heat loss last week.
He said it was to add volume not hydronic separation.
I was originally quoted for a 12kW but he said we might get down to an 8 as the house is well insulated, wet UFH etc

Also mentioned the Aira units are based on the Vailliant. Made in Poland.

 

[NoNameNoNumber]

Yes Aira, and I understand a buffer tank piped as separator isn’t a volumiser which is why I asked for clarification.