Sunamp and Samsung R290 heat pumps?

[JohnnyC]

Hi there,

 

Just wondering if anyone has tried pairing a Sunamp Thermino hp-SG (or xPlus) with a Samsung R290 heat pump and whether this worked.

 

From the Sunamp manual, it would seem as if only R32-based Samsung heat pumps would be compatible/supported by Sunamp (either for hp-SG units or the new xPlus ones with the respective SG key). However, the installation manual for these configures them to set a cap on the hot water temperature at 50C and make the last increase in temperature through the Sunamp built-in heating element. Of course, this negates any COP benefits of getting the heat pump to heat the PCM.

 

I've asked Sunamp and Samsung over X re support for R290-based units, but they don't seem to know themselves.

 

I guess my alternative would be to use a Valiant heat pump, which my installer is not keen on. (I do not have space for UVC.)

 

Thanks very much in advance!

 

[ProDave]

I would read all the threads on here about sunamps and then ask yourself, why do I want to pay a lot more for a complicated magic box that claims wonderful things but comes with limitations and complications, where a traditional, dependable and reliable unvented hot water cylinder will do all I want without the complications.

 

In my mind you need to have a VERY good reason not to use an UVC.  What is your good reason?

[SteamyTea]

7 hours ago, JohnnyC said:

I do not have space for UVC

If you can get an SA in, you can get a water cylinder.

 

7 hours ago, JohnnyC said:

the installation manual for these configures them to set a cap on the hot water temperature at 50C and make the last increase in temperature through the Sunamp built-in heating element

That is the physics of phase change materials.

You need a pump the energy is at just slightly higher than the phase transition temperature.

[Russdl]

Just for balance I believe there are some of us here who are still happy with their Sunamps, I certainly am despite having the thermistor string replaced under warranty a couple of years ago.
 

In the OP’s proposed set up surely the complex magic box is the ASHP not the Sunamp, there are no pumps etc in Sunamps anymore.
 

Personally however I do feel that a Sunamp is best as a stand alone hot water solution and not coupled to some other hot water creator. That of course then needs some other solution for heating and if significant heat is required then the ASHP has got to be the way I guess. 
 

So after bravely defending the Sunamp I’d have to agree with @ProDave and @SteamyTea in this instance. 
 

 

Just off to get my hat 🏃🏼
 

[JohnMo]

7 hours ago, JohnnyC said:

(I do not have space for UVC

First question is your installer proposing a buffer? If so could deleting that free up space? Slim line cylinder in a corner?

 

Loft or space outside for an insulated shed?

 

Hybrid, heat pump for heating, a combi boiler for DHW 

[JohnnyC]

Thank you all very much for the feedback.

 

I have read most of the Sunamp threads in the forum, and I still believe that this is an ideal solution for me. Apologies, I should have introduced these in my first post.

 

I'm renovating a 4-bed. Vitorian mid-terrace (ca. 1900) in west London. The setup that I have in mind is as follows:

 

- UHF throughout the property (already installed)

- No radiators (already removed)

- No gas boiler (already removed)

- DHW through a Sunamp 300 hp-SG(VT?)

- Heat pump for whole-house heating and DHW (R290-based)

 

I already have PV (5kWp) and batteries (15kWh).

 

I am aiming to run the UFH at a flow temperature of 35C for a >4.5 COP, and the Sunamp (I'm not sure about COP, but I would expect this to be much better than 1) to provide all DHW needs.

 

I do not want to have to use direct electricity to heat the Sunamp since it negates the COP gains of doing this through the heat pump. Hence I need an R290-based heat pump to achieve this since these can heat up to 75C. My installer suggested using a Samsung R32 heat pump, but this does require heating through the heating element because of the Sunamp configuration, which I won't do.

 

So the original question was as to whether anyone would have successfully installed a Samsung R290 mono-block heat pump with a Sunamp hp-SG (or an xPlus with a SG-01 Optimino key). Samsung customer service also won't tell me because their support team only speak to engineers.

 

Re UVC, I do not have any loft/outside available space. Also, I am keen to not have to do the annual service, pump changes, etc. Surely these will result in a higher cost over 10 years' time compared with the higher initial cost of the Sunamp? But please correct me if I'm wrong and I'll try and make space for the UVC.

 

Thanks a lot again!

 

 

 

[SteamyTea]

2 hours ago, JohnnyC said:

Surely these will result in a higher cost over 10 years

Has any SA lasted a decade yet?

[Russdl]

@SteamyTea I’ll get back to you in a few years. 
 

Perhaps it’s only me on here who has a Sunamp that is post the ‘Sunamp PV’ model? 
 

If it dies I would replace with the same.
~~~

Currently, over winter you could argue it has a COP of about 2.5 because it’s only charged on cheap rate electricity which, I understand may disappear one day. 
 

Since the battery has been installed it charges for bugger all off the accumulated PV - obviously the battery cost a wee bit and I haven’t sat down to work out the ‘pay back’ time because I wanted a battery. Actually I think I want another one. 

 

[SteamyTea]

11 minutes ago, Russdl said:

Perhaps it’s only me on here who has a Sunamp that is post the ‘Sunamp PV’ model

They did seem to give a lot of bother.

 

11 minutes ago, Russdl said:

obviously the battery cost a wee bit and I haven’t sat down to work out the ‘pay back’ time because I wanted a battery

Don't scare yourself, it may work out at 50p/kWh.

 

  

11 minutes ago, Russdl said:

Currently, over winter you could argue it has a COP of about 2.5 because it’s only charged on cheap rate electricity which

No, that is not the way to work it out.  You have to take your mean price.

So as I use about 11 kWh/day, and 10 of those are at 15p and the other one at 35p, that is 17p/kWh.

 

 

Edited April 4 by SteamyTea

[Russdl]

16 minutes ago, SteamyTea said:

No, that is not the way to work it out.  You have to take your mean price.

 

I don’t.
 

Talking domestic hot water here. 
 

Over winter it (currently) charges off peak at 9p. It never charges outside of that period so that is what it cost for my domestic hot water. 
 

From now/spring onwards (thanks to the battery and the existing PV) it costs the square root of bugger all (apart from PV, battery etc etc). 

[JohnMo]

8 hours ago, Russdl said:

@SteamyTea I’ll get back to you in a few years. 
 

Perhaps it’s only me on here who has a Sunamp that is post the ‘Sunamp PV’ model? 
 

If it dies I would replace with the same.
~~~

Currently, over winter you could argue it has a COP of about 2.5 because it’s only charged on cheap rate electricity which, I understand may disappear one day. 
 

Since the battery has been installed it charges for bugger all off the accumulated PV - obviously the battery cost a wee bit and I haven’t sat down to work out the ‘pay back’ time because I wanted a battery. Actually I think I want another one. 

 

But what is different - an UVC can do just the same functionality for a 1/3 of the cost of purchasing a cylinder instead of a sunamp?

 

What am I missing?

[ProDave]

10 minutes ago, JohnMo said:

But what is different - an UVC can do just the same functionality for a 1/3 of the cost of purchasing a cylinder instead of a sunamp?

 

What am I missing?

The USP of a sun amp has always been it's vacuum insulation panels and so a lower heat loss than a conventional cylinder.  And a smaller volume for the same heat storage capacity, though it's form factor favours those who are restricted with height, they take up as much if not more floor space than a normal cylinder.

 

Has anyone actually worked out how much you save due to the reduced heat loss of the sunamp and if that is it's only tangible benefit, what is the payback time of that saving?

[SteamyTea]

11 minutes ago, JohnMo said:

What am I missing

Temperature stability maybe because of the phase change temperature, but that can be affected by flow rate.

[Russdl]

No annual maintenance requirement. 
 

Regarding heat loss, if fully charged and then unused for a 24hr period it takes around 1kWh to recharge (which I think is a bit more than advertised in the blurb). What would be the loss from a fully charged 300L UVC?

[SteamyTea]

On 05/04/2024 at 08:48, Russdl said:

What would be the loss from a fully charged 300L UVC?

About the same.

I have a very bog standard 200lt E7 VC and that does not lose much more.

[JohnMo]

11 minutes ago, Russdl said:

No annual maintenance requirement. 
 

Regarding heat loss, if fully charged and then unused for a 24hr period it takes around 1kWh to recharge (which I think is a bit more than advertised in the blurb). What would be the loss from a fully charged 300L UVC?

Maintenance needs would take several life times to recover the capital costs. How many people actually service their cylinder annually - would bet not many, as many would have no clue they needed to.

 

Heat loss would suspect more heat is lost from the pipes than the sunamp or cylinder. Can't answer your question about energy lost over 24hrs as we keep using it.

[joe90]

Regarding heat loss, unless In summer the heat is within the house so is it an actual loss?

[SteamyTea]

7 minutes ago, joe90 said:

Regarding heat loss, unless In summer the heat is within the house so is it an actual loss?

I always used to think that, but now I am not so sure.

But as it will hardly raise the temperature at all, and air leakage will just about make it unmeasurable, it is hardly a gain.

Then comes the second part, the CoP of the heat pump (different for direct heating).

Take today, my OAT is about 10°C and my IAT about 21°C, a reasonably set up ASHP will probably be getting a CoP of around 4.5.

But to heat water, the CoP may be about 3, and if that water was heating early morning, maybe only 2.5.

So in reality, loosing that 1 kWh from the cylinder costs more.

[Russdl]

4 hours ago, JohnMo said:

How many people actually service their cylinder annually - would bet not many, as many would have no clue they needed to.

Fair point but in the unlikely event it all going pear shaped the insurance claim may be problematic. 
 

4 hours ago, JohnMo said:

Heat loss would suspect more heat is lost from the pipes than the sunamp or cylinder.

Maybe. Wherever it’s lost from and/or to it needs replacing, so the less the Sunamp/UVC lose the better surely?

 

As a general thing, I can’t think of one item in this house that was bought with a view to when it would have paid for itself. That was definitely not in my head when I decided on the Sunamp or, more recently, the battery. Who knows, if the Sunamp soldiers on for 20+ years it may well have paid for itself over some other option but I won’t be sitting down to do the sums. 

[Maurice Ponk]

I would also

On 04/04/2024 at 12:03, JohnnyC said:

Thank you all very much for the feedback.

 

I have read most of the Sunamp threads in the forum, and I still believe that this is an ideal solution for me. Apologies, I should have introduced these in my first post.

 

I'm renovating a 4-bed. Vitorian mid-terrace (ca. 1900) in west London. The setup that I have in mind is as follows:

 

- UHF throughout the property (already installed)

- No radiators (already removed)

- No gas boiler (already removed)

- DHW through a Sunamp 300 hp-SG(VT?)

- Heat pump for whole-house heating and DHW (R290-based)

 

I already have PV (5kWp) and batteries (15kWh).

 

I am aiming to run the UFH at a flow temperature of 35C for a >4.5 COP, and the Sunamp (I'm not sure about COP, but I would expect this to be much better than 1) to provide all DHW needs.

 

I do not want to have to use direct electricity to heat the Sunamp since it negates the COP gains of doing this through the heat pump. Hence I need an R290-based heat pump to achieve this since these can heat up to 75C. My installer suggested using a Samsung R32 heat pump, but this does require heating through the heating element because of the Sunamp configuration, which I won't do.

 

So the original question was as to whether anyone would have successfully installed a Samsung R290 mono-block heat pump with a Sunamp hp-SG (or an xPlus with a SG-01 Optimino key). Samsung customer service also won't tell me because their support team only speak to engineers.

 

Re UVC, I do not have any loft/outside available space. Also, I am keen to not have to do the annual service, pump changes, etc. Surely these will result in a higher cost over 10 years' time compared with the higher initial cost of the Sunamp? But please correct me if I'm wrong and I'll try and make space for the UVC.

 

Thanks a lot again!

 

 

 

I would also like to heat a Sunamp with a Samsung R290, even though there is no Sunamp 'Optiminio Key' available (yet ?)

 

A Sunamp would fit perfectly into our small basement space and allow our existing 300 Litre thermal store to be removed from the only fitted Cupboard space in our entire house !

 

The Samsung looks like it could give a 65 degree flow temperature 24/7, which is handy, as that has allowed me to fulfill my heat-loss requirement with all my existing radiators ...

 

SO,

 

prior to there being an optiminio key available, to allow the sunamp & Samsung to talk to each other, is there a way to plumb in the Sunamp in a 'dumb' way, so that it simply re-heats every time the Space heating flow temperature hits 65 degrees ?

 

Thanks !

[Nickfromwales]

12 hours ago, Maurice Ponk said:

is there a way to plumb in the Sunamp in a 'dumb' way, so that it simply re-heats every time the Space heating flow temperature hits 65 degrees ?

Only if you want zero warranty. They'll just say "non-standard installation" when you attempt to claim. They did that to 2 clients who claimed for failed units, ironically they did the design on one lol.

 

As far as zero annual maintenance, these have expansion vessels, so those need to be regularly checked and maintained on a Sunamp / Thermino / Aquafficient, or again....no warranty. You need to drain down, test the pre-charge pressure, and then fill back up again.

 

On 05/04/2024 at 08:25, ProDave said:

Has anyone actually worked out how much you save due to the reduced heat loss of the sunamp and if that is it's only tangible benefit, what is the payback time of that saving?

At the current prices for these things, installed, you (and the salty box), would need to outlive your great grandchildren.

[JohnMo]

On 05/04/2024 at 08:25, ProDave said:

Has anyone actually worked out how much you save due to the reduced heat loss of the sunamp and if that is it's only tangible benefit, what is the payback time of that saving?

I did and it's included in another recent thread. As @Nickfromwales says payback is a life time or two. With a heat pump something like 50 to 140 years depending on the tariff and how much you actually loose from a standard cylinder when water is stored at below 50 degs and how much you pay for a cylinder. I did add into this the loss of CoP as the full recharge has to be completed at full temperature instead a slow ramp to full temp for a new cylinder.

 

Bonkers idea

[Nickfromwales]

9 hours ago, JohnMo said:

Bonkers idea

100%. It’ll be a huge regret for the OP to follow the proposed route. 👎

[JohnnyC]

Hi there,

 

In case this is useful to anyone, after a few weeks, Samsung has confirmed that the SA will work with Samsung R290 heat pumps.

 

I have decided to go down the UVC in the end sacrificing additional space. I couldn't justify the lower efficiency having to heat water to 65C for the SA.

 

Thanks for the feedback.