@upnorthandpersonal welcome to the forums and I think you’re our first Finnish member! Love the avatar. I’m pretty sure we can learn from your insanely cold experiences. Is your hearing system water based (rads, UFH) or air?

Posted by: @editor

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Is your hearing system water based (rads, UFH) or air?

Underfloor hydronic, powered by both the heat pump and a wood gasification burner (both coupled to a 3000L thermal store). In addition, I have a masonry fireplace:

Hi Everyone,

I've just joined the forum and full of nervous anticipation regarding commencing our new build property in the coming weeks.

Our development is located in South West Scotland within an extensive plot; hence with this in mind we are considering GS heat pump for domestic heating and hot water.

We have no experience with heat pump technologies, and would be most grateful for some advice regarding GS systems and manufacturers to consider/avoid.

At present we are considering perhaps a NIBE or Viessman heat pump....but realise there are other systems by Thermia and Stiebel Eltron and more.

We have found it a little difficult to simply find out individual item costs without having to speak directly to installers (although we are aware of the importance of getting the system right).

Hopefully we can obtain pertinent advise from the valued members within the hub.

Look forward to hearing from you.

Kind Regards,

Wheatie.

@wheatie welcome to the forums, and it must be a nervous and exciting time. What I'd suggest is starting a new forum thread/topic here dedicated to your project, outlining everything: https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/

There's a lot to discuss pertaining to GSHP units.

@editor

Kind thanks for the warm welcome and prompt response - I shall indeed reach out to the wider team..... 👍 

Posted by: @wheatie

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At present we are considering perhaps a NIBE or Viessman heat pump....but realise there are other systems by Thermia and Stiebel Eltron and more.

We have found it a little difficult to simply find out individual item costs without having to speak directly to installers (although we are aware of the importance of getting the system right).

Welcome! I did something similar (look at brands) when I was looking for what I think is the most common case of replacing a fossil fuel system with a heat pump, which benefits from a gov £7.5k grant.

Even when I could find prices of heat pumps I was usually missing the optional control components that are managed by dedicated apps to adjust temperature and find running costs (that depend of course on tariffs, etc). I had the sense the pumps themselves are similar, it is in the control etc aspects that they differ for a user. And of course most brands do not design nor manage any installs, which for me would be the most important.

But perhaps the best is to have a look for a thread related to new build and ask there. Or start a new one! 

Posted by: @wheatie

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At present we are considering perhaps a NIBE or Viessman heat pump....but realise there are other systems by Thermia and Stiebel Eltron and more.

GS heat pumps are quite expensive and relatively uncommon.  That said they are said to be very good.  You may want to consider air source (air to water) as an alternative, if you do the (high end) manufacturers you mention also do air source and you might want to consider 'mid market' alternatives like Mitsubishi or Vaillant.

That said the most important thing is the installation/installer.  A poor heat pump can perform perfectly well with a good install and a very good heat pump can perform poorly with a bad install.  Things to look for are

• Match the capacity to the house, dont oversize.  If you can sense check the capacity in any way do so 
• Do not design in external controls, the heat pump itself has all the controls you need and most external controls compromise performance.  Any TRVs/room stats will be used as limiters only (in the case of excsss solar gain or other disturbances) not controllers
• One zone, all designed to operate at the same (low) flow temperature- certainly no more than 45 and ideally lower.  35 or less if UFH
• Direct connection from heat pump to emitters, no buffer tank, low loss header or plate heat exchanger in between.  A 2 port volumiser in the flow (not between flow and return) is acceptable

In fairness I should say these apply to air source, but I cant see why the same shouldn't also apply to ground source (and, if they dont, your installer should be able to explain why not!).

Feel free to start a thread about your project and ask for further explanation.

Some quick signposting… here’s at @wheatie’s dedicated thread: https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/new-gs-system-advice

@kev1964-irl Just seeing your post now. I'm also based in Ireland and have been through the process of solar (2021) and heat pump (2023). I too was initially advised by one supplier to get a 14kW heat pump but ended up with a 10kW which has operated fantastically well. So if you have any questions re. the local market just let me know.

@gc61 Thanks for the offer - Which brand did you choose and how was your installer with regard to final commissioning and post install support?

And just to close off the initial point I went back to the designer of the 12kw system saying that two other sets of calculation came to 8kw. They re-did their figure, found a mistake and owned up to it!

@editor @kev1964-irl This discussion might be best had offline. Can you advise how we do this through the forum rather than swapping emails publicly? Tks.

Posted by: @gc61

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This discussion might be best had offline.

You can send private messages via the Messages (envelope icon) button under My Dashboard top right of the page, but generally we like to keep discussions in the open so others can benefit, unless there really is sensitive private material involved. Naming of names of installers good and bad is fine, just stick to the facts if there are negative comments.