Choice of HT ASHP for retrofit

[sharpener]

That is my low-temp TS, which really acts as a buffer. I have 3x 750L TS - low / med / high. Each can be heated via HP or gas boiler / CHP and each has 3x 3kW heating elements near the bottom.
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Hopefully that makes more sense!

Thanks @jonc_uk. What make and model TS did you go for (a link would be really helpful). Given the size of the storage did you look at Sunamp?

[jonc_uk]

They were custom made by Advance Appliances https://www.advanceappliances.co.uk/

Looked like this before plumbing:



I did look at Sunamp, but decided in the end that water is a great heat storage medium without complicating things. The stores have plenty of in and out connections with spares, 3x electric heaters and 5x sensor pockets at different heights. I have also been impressed with their built-in insulation.

[sharpener]

Thanks, useful. Can I ask who did your system design or was it DiY?

I came across Advance separately as a supplier of custom tanks to Kensa as suggested above by @nowty, some useful information there. Will contact them tomorrow.

My heating demand is almost entirely while there is no source of cheap electricity - solar or off-peak - and vv. Will probably need two tanks to get the storage capacity, one will supply the big rads in the living room from late afternoon (not necessarily at max temperature) and then the U/F. Meanwhile the other tank will keep hot to heat up the bedrooms later in the evening, this store needs to be hotter as I cannot increase the radiator sizes there by much.

So I may want to run them at different temps like you, but for different reasons. Hence the plan to have an HT ASHP, but vary the temp it runs at depending on what it is feeding in order to maximise the CoP.

[sharpener]

A lot of discussion on BuildHub about the vfm and good support of the InverTech range of HPs from CoolEnergy e.g. this package, does anyone have any experiences they can add?

[sharpener]

Still in the planning phase. Have had one estimate and one decline to bid. Both say I will need to swap out all the rads which will be a major expense.

So I am now looking into using the Daikin Altherma HT range as a way of achieving more of what I want without wholesale replacement of rads and HW cylinder. They are split systems but the overall capital cost might be much the same with less disruption. They also have a bi-zone add-on which allows rads and UFH to run at different temps which sounds promising. The CoP will not be wonderful but with free PV available might just be enough.

Do ppl have experience of Daikin in general and/or this range in particular they would like to share?

[jonc_uk]

I have Daikin aircon in Portugal. I would consider it slightly superior to Mitsubishi. I think it is the brand of choice for commercial install there (eg. shops).

I have had zero problems with 6 split units in 7 years.

[Joeboy]

Still in the planning phase. Have had one estimate and one decline to bid. Both say I will need to swap out all the rads which will be a major expense.

So I am now looking into using the Daikin Altherma HT range as a way of achieving more of what I want without wholesale replacement of rads and HW cylinder. They are split systems but the overall capital cost might be much the same with less disruption. They also have a bi-zone add-on which allows rads and UFH to run at different temps which sounds promising. The CoP will not be wonderful but with free PV available might just be enough.

Do ppl have experience of Daikin in general and/or this range in particular they would like to share?

We used Daikin aircon unit split system offshore. They ran for about 4 years 24/7 before needing replacement. This was in Nigeria and Saudi so we are talking harsh working conditions. Seen plenty others crater after 2 years. Thumbs up for Daikin.