DanDee

Question - what is there to blend?

I really wonder what makes the COP increase of the Chofu heat pump when they land in UK, is it the tea or the humour?

Water doesn't reverse the flow as it's taking the heat from the return side, and the flow becomes colder. https://emoncms.org/heatgeek

In terms of exporting pv excess it is indeed that simple, unless you are in Australia with a neighborhood/substation transformer, where there is so much pv excess with all the people at work not using the energy. If you are in UK, your next door neighbour will be the one using that export.

If I would install a HP that falls into MCS approved list(all of them prob), I wouldn't bother with paying extra taxes. A HP installed through MCS or private does the same noise.

https://www.waermepumpen-verbrauchsdatenbank.de/index.php?button=verbrauch

https://heatpumpmonitor.org/

https://tools.bregroup.com/heatpumpefficiency/background

https://www.nibe.eu/assets/documents/23940/231758-7.pdf Page 38 Menu 5.1.23 - compressor curve

https://www.vaillant.cz/downloads/projek-n-podklady/kl-06-e2-verze-01-18012023-2564719.pdf Capacity tables from page 34

Download the pdf for this google search: Ecodan_ATW_Databook_R32_Vol5.5 https://library.mitsubishielectric.co.uk/pdf/book/Ecodan_ATW_Databook_R32_Vol5_5