Confused on electricity supply needs and ASHP

[pstunt]

Hi,

To set the scene, I am converting an old stable to a 5 bed home up here in County Durham. The site does not currently have electricity but I am in the process of jointly getting a single phase provided in conjunction with the owner of the plot next door ( Who happens to be a builder building for himself. ) We are doing doing it jointly as it's a fairly long run from the nearest pole ( 120m ) and and an extra 30m for me on top. We chose single phase purely down to cost as it will be at least £20K and more even for that and to have 3 phase cable will be even more cost. I dont know what the cost difference would actually be as I was told you cant actually be told without making a formal application which costs several hundred pounds. 

 

Accepting that single phase is the only option does that realistically restrict my options on choosing an ASHP ? I am raising this question as a result of a quote from BPC Ventilation which included a 16KW Panasonic Aquarea Mono-Bloc T-CAP for our 373m2 single story build. My concern is that I think this needs 3 phase ( something I am querying with them ) and assuming it does then even if I went with 2 smaller units ( for arguments sake, 2 8kW units ) does that still present me with a load issue. 

 

Clearly I slept through my physics classes all those years ago. So apologies up front if this is basic stuff.

 

 

[Conor]

Welcome

 

First step. Is a 16kw ashp needed? Our house is 315m2 and we are installing a 9kW ashp, which in itself is over specced.

 

If you're heat losses mean a 16kW ashp is needed, I would closely look at your insulation, airtightness and glazing strategy so see how to reduce the peak heating demand.

 

Secondly, 16kW is the max OUTPUT of the heatpump. Check the specs and see what the max power consumption is. If it's less than 7kW then single phase is sufficient.

Edited October 22, 2021 by Conor

[Dan F]

13 minutes ago, pstunt said:

16KW Panasonic Aquarea Mono-Bloc

 

I agree with @Conor that you should make sure you definitely need 16kW.  Get some more quotes if required from reputable suppliers who'll do the heat loos calculations if possible.

 

If you do need to use 16kW, it looks like that that Panasonic model is rated 26A and is available in a in single-phase version.   Is the proosed supply 100A?  If it is then 16kW ASHP will be fine,  just as long as you 74A is enough for everything else you need.

 

 

Edited October 22, 2021 by Dan F

[ProDave]

As above 16kW outpur heat pump should be fine on single phase.  Make sure on your electricity application you state it is inverter driven soft start.

[pstunt]

Thanks all. You have highlighted areas I need to look into more and then if you don’t mind, I will come back with some updates. One of those areas is working out the heat loss.

[George]

Samsung 16kW Gen6 has a power demand of 3.8kW nominal. 

 

I expect others will be similar. 

 

Do expect the DNO to see '16kW' and freak out, though. My installed had to get Samsung distributor to contact the DNO and explain how the ashp worked, they were fine it then on single phase. 

Edited October 25, 2021 by George

[joth]

On 22/10/2021 at 16:32, pstunt said:

We chose single phase purely down to cost as it will be at least £20K and more even for that and to have 3 phase cable will be even more cost.

Depends how the pole is loaded up, but it's possible they won't want you both on a single phase so might pull 3ph as far as the neighbour's plot at least.  With UKPN i was able to get a verbal "estimate" from the surveyor when they made their visit, prior to putting in my formal application, but sounds like that's not an option here.

 

[pstunt]

3 hours ago, joth said:

Depends how the pole is loaded up, but it's possible they won't want you both on a single phase so might pull 3ph as far as the neighbour's plot at least.  With UKPN i was able to get a verbal "estimate" from the surveyor when they made their visit, prior to putting in my formal application, but sounds like that's not an option here.

 

Would be good if they did provide 3 phase regardless but I am never that lucky. I did have an initial site assessment from Northern Power who informally told me that the cable for single phase was something like £140 per meter and not too much more for 3ph but couldn't be more specific and I am led to believe there was a price cap on cable cost then ( 6 months ago ) which has apparently been raised since. Sounds like I will know for sure when I actually get my quote.

 

As a side note, BPC have come back to me and said if I only have 1ph then I cant have this model anyway as it does require 3ph and they will quote for 2 alternative units. This is where my lack of knowledge starts to show, but does it make it ok to have say 2 x 8KW units running in parallel. Does this still not present a load issue ? To be clear they have provided an alternative solution yet just said they would suggest 2 smaller units instead. 

[Bonner]

Northern Powergrid initially quoted me a 3 phase connection for a few hundred £ more than single. When it came to formal quotation after survey, the network needed upgrading at a cost of £15k! I settled for single phase as it is unnecessary for most homes anyway.

Plenty of single phase 16kW ASHP’s available, if you really need that size. Two units would be excessive, talk to other suppliers.

[pstunt]

10 minutes ago, Bonner said:

Northern Powergrid initially quoted me a 3 phase connection for a few hundred £ more than single. When it came to formal quotation after survey, the network needed upgrading at a cost of £15k! I settled for single phase as it is unnecessary for most homes anyway.

Plenty of single phase 16kW ASHP’s available, if you really need that size. Two units would be excessive, talk to other suppliers.

Thanks. I am getting on the case, as yourself and others have suggested, which is to speak to other suppliers.