Happy that A2W will prove less effective, although @bobflux comments about cooling with just AC and with slab then AC are interesting. 

Not looking for American style freeze yourself, just avoid the overheat. 

With regards to recirculation for DHW, instant hot water is something I am going to strive for, having been in properties with and without. My thinking is properly(read overly) lagged pipework, on a zoned system based on occupancy/motion gives a good trade off in terms of functionality and standing losses. 

The POU idea is interesting, and like I mentioned I have been circling around this for a while. My issue is the house will be long so tank near bathrooms isnt achievable. I did briefly look at dual tanks at either end. 

My issue is making sure I have enough power output available from the batteries, I can easily get 60kW, which is just shy of 2 full DHE27s, which would allow 2 simultaneous showers at either end of the house. Taking from cold water mains up to shower temp, at shower rate full flow.

But anything more than that at the same time and start being limited. To go to the next size of gateway, and with enough power costs considerably more. More than would be ever lost to heat loss (or extra cooling in the summer due to that)

Whereabouts in the country are you based, @chastity_outward053simplelogi? It feels to me like you're now at the stage where it's worth sounding a few installers out to pick one you're happy to work with, then providing your plans to them so they can suggest based on actual details. This thread has quickly got into a surprising amount of detail and making design decisions before involving an installer feels like the tail might be starting to wag the dog.

@majordennisbloodnok 

No that is just me trying to design and understand as much as possible myself. 

I am actually working in the middle east at the moment, but we have just put an offer in on a plot of land in Hampshire. It will be a few years before we break ground. 

But I have been going through everything with as finer tooth comb as I can mange to work out what is within my capability to do myself and what I cant. 

And also get a realistic total project cost

Posted by: @chastity_outward053simplelogi

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@majordennisbloodnok 

 

No that is just me trying to design and understand as much as possible myself. 

I am actually working in the middle east at the moment, but we have just put an offer in on a plot of land in Hampshire. It will be a few years before we break ground. 

But I have been going through everything with as finer tooth comb as I can mange to work out what is within my capability to do myself and what I cant. 

And also get a realistic total project cost

 

That makes far more sense, and is, of course, an ideal way of using the forum. Chewing over multiple alternatives can certainly give surprising results and there's no shortage of people here who know their stuff and can think laterally.

Do bear in mind, of course, that if you're thinking several years ahead you're also potentially planning for solutions that haven't been brought to market yet. One criticism of hot water heat pumps (DHW cylinders with small dedicated ASHPs on top) is that they're not the quickest to reheat the water after the tank has been emptied, but if A2A gains more traction in the UK then the whole issue of how to provide DHW may well get some inventive attention in ways that might affect your outlook one way or another.

Interesting times...

Posted by: @chastity_outward053simplelogi

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My issue is making sure I have enough power output available from the batteries, I can easily get 60kW, which is just shy of 2 full DHE27s, which would allow 2 simultaneous showers at either end of the house. Taking from cold water mains up to shower temp, at shower rate full flow.

You could consider putting the DHE27 on the hot water pipe near the shower.  Then you get instant hot water at a COP of 1, whilst the water from the tank (at a COP of 3) works its way to the outlet.