Sunamp container bulging

[PeterW]

36 minutes ago, Ed Davies said:

 

According to the Sunamp manual the maximum constant heat source flow temperature is 85 °C. Linked from le-cervaux's post . Table 4.2a.

 

Strangely, their section of solar thermal doesn't mention limiting to this.

 

This is where I see the flaw in their design. Whilst removing a pump (moving parts) and a heat exchanger, they have introduced an issue where they have exposed the core of the product to a heat source that can exceed 100c - a resistance heater. 

 

If they had kept the H-Ex in the design and fitted a standard Willis heater tube instead - even in the bottom of the case to allow for permanent immersion and thermosyphoning - then it would have allowed multiple different ways to warm the goo. PV, E7, ASHP, Solar Thermal - all could be pumped round the H-Ex circuit or input into the Willis, and even with the slight loss in performance it would have been fine. 

 

My view that I’ve shared with @Nickfromwales for a while is that it’s not that @scottishjohn  the accountants have been at this, but the product engineers haven’t had a look in and the scientists are still experimenting ... 99% of these issues would go away with a couple of months of decent product engineering, and with probably some cost savings to be made too. 

[Jeremy Harris]

11 minutes ago, Ed Davies said:

 

According to the Sunamp manual the maximum constant heat source flow temperature is 85 °C. Linked from le-cervaux's post . Table 4.2a.

 

Strangely, their section of solar thermal doesn't mention limiting to this.

 

That would make it easy to just use a  basic UniQ heat cell, with the low power heat exchanger being used for hot water charging and the high power heat exchanger being used as an instant water heater.  It should be pretty easy to control the charge circuit temperature so that it is always above the phase transition temperature of 58 °C but under the maximum of 85 °C.  Combining the functionality of excess PV generation diversion and charge control should be pretty straightforward.

[Onoff]

Who mentioned solar thermal? Rub it in why don't you!

[Jeremy Harris]

4 minutes ago, PeterW said:

 

This is where I see the flaw in their design. Whilst removing a pump (moving parts) and a heat exchanger, they have introduced an issue where they have exposed the core of the product to a heat source that can exceed 100c - a resistance heater. 

 

If they had kept the H-Ex in the design and fitted a standard Willis heater tube instead - even in the bottom of the case to allow for permanent immersion and thermosyphoning - then it would have allowed multiple different ways to warm the goo. PV, E7, ASHP, Solar Thermal - all could be pumped round the H-Ex circuit or input into the Willis, and even with the slight loss in performance it would have been fine. 

 

My view that I’ve shared with @Nickfromwales for a while is that it’s not that the @scottishjohn that the accountants have been at this, but the product engineers haven’t had a look in and the scientists are still experimenting ... 99% of these issues would go away with a couple of months of decent product engineering, and with probably some cost savings to be made too. 

 

I agree 100% with this. 

 

It's very easy (and damned dodgy) to allow constant tinkering with the design, in order to try and experiment with different ideas, just because it's interesting.  I've spent a fair bit of my career being allowed, even encouraged, to do this, but I was never required to produce anything for production.  It shows in all the changes I've made to our home as I've gone along, as I find it damned hard to stop experimenting.

 

I'm convinced that binning the direct heater, and fitting a separate hot water charge circuit would remove 99% of the UniQ eHW problems when used as a thermal store heated primarily by PV generation.

[Ed Davies]

13 minutes ago, PeterW said:

If they had kept the H-Ex in the design and fitted a standard Willis heater tube instead

 

Yes. But clearly putting the immersion right in the goo is cheaper and fine for most people most of the time. If you want to do something odd (as many of us will) then the best bet is using the low-power circuit to charge with an external Willis heater or whatever. Nothing's lost.

[PeterW]

@Ed Davies doesn’t it miss the point though of not being able to use it to take excess PV without mucking about ..? The issue if you look through the product catalog is there are too many variants - you basically need a charge circuit and a goo box. More capacity = more goo boxes, you don’t need another charge circuit per box ... 

[Guest Alphonsox]

2 minutes ago, Ed Davies said:

 

Yes. But clearly putting the immersion right in the goo is cheaper and fine for most people most of the time. If you want to do something odd (as many of us will) then the best bet is using the low-power circuit to charge with an external Willis heater or whatever. Nothing's lost.

 

I disagree - Sunamp seem to be loosing their USP in the domestic market. If they cant reliably capture excess renewable energy then they move to being just another Megaflow competitor.

[scottishjohn]

2 hours ago, JSHarris said:

 

There are two separate and unrelated issues around bulging cases.

 

The most obvious and noticeable is the design flaw with the insulation at the top of the unit, which is too thick/too resilient to fit in the space available and pushes the lid upwards.

 

The second isn't related to space, it is down to the flexibility of the case itself.  The heat cell looks a bit like a plastic jerry can, and like a plastic jerry can it tends to bulge outwards when full, unless it is properly restrained.  The Sunamp PV had cells with a similar construction, but also had an extremely rigid, bolted together, heavy duty alloy case.  The Sunamp PV case was much more rigid than that of the Sunamp UniQ range, as its bolt-together design meant that there were flanges that stiffened it up a great deal.  I commented on how robust the case was when our Sunamp PV was delivered:  http://www.mayfly.eu/2015/10/part-forty-getting-into-hot-water-episode-two/

 

The Sunamp UniQ range have a single piece alloy case that is a lot less rigid than the Sunamp PV, and as a consequence it isn't stiff enough to stop the heat cell from bulging.  Stiffening the case, as @Nickfromwales has mentioned, will fix this, i'm sure.

so that comes back to what i said before "bean counters"--they ALWAYS FXXX  engineers designs 

[PeterW]

6 minutes ago, scottishjohn said:

so that comes back to what i said before "bean counters"--they ALWAYS FXXX  engineers designs 

 

I don’t think you’ve read my response. 

 

Accountants have been nowhere near this - it’s still a prototype and basically the scientists are still playing !! A product engineer would sort this in a matter of months - it’s not about the cost, it’s about making the thing survive the real world first ...

[Stones]

13 minutes ago, Alphonsox said:

 

I disagree - Sunamp seem to be loosing their USP in the domestic market. If they cant reliably capture excess renewable energy then they move to being just another Megaflow competitor.

 

That may be their plan, having got an A++ energy rating because of the low heat loss, it opens up a huge market with big developers seeking an easy SAP point or two.

[willbish]

My UniQ eHW9 & eDuel12 is sat on a pallet in Sunamp HQ awaiting dispatch when my build is ready.

 

I read all the Sunamp bumf prior to purchasing the UniQ but also based my choice on the balanced opinions of those on this forum who own/ed the Sunamp PV. To think the UniQ is unable to deliver the same fundamental feature of the previous model is unacceptable.

 

I will be watching closely how Sunamp respond but am hopeful they will be able to deliver an adequate solution. Although I'm slightly skeptical as a hardware alteration as well software will be a significant upgrade.

 

I don't think it's unreasonable to assume that the UniQ would behave with similar characteristics to the SAPV, therefore, like @JSHarris should be entitled to a refund if we so desire 

 

 

[scottishjohn]

1 minute ago, PeterW said:

 

I don’t think you’ve read my response. 

 

Accountants have been nowhere near this - it’s still a prototype and basically the scientists are still playing !! A product engineer would sort this in a matter of months - it’s not about the cost, it’s about making the thing survive the real world first ...

so what you are saying is it should never have been released then ,but they have made the pcm case thinner than the first one from what i read .

there should be no swelling of the pcm case -so they have made it too thin--any way its basically not fit for purpose -

and if you remember i said this very early on when i referred to "tombstone technology " as they called it in the aero industry 

-i,ll revisit this thread in a years time and see what they are like then  once production is moved to china !!.which it will be , nothing more certain.

[Onoff]

6 minutes ago, scottishjohn said:

so what you are saying is it should never have been released then ,but they have made the pcm case thinner than the first one from what i read .

there should be no swelling of the pcm case -so they have made it too thin--any way its basically not fit for purpose -

and if you remember i said this very early on when i referred to "tombstone technology " as they called it in the aero industry 

-i,ll revisit this thread in a years time and see what they are like then  once production is moved to china !!.which it will be , nothing more certain.

 

I was just about to mention China. Money to burn, they'll make Sunamp an offer they can't refuse for the patents and it'll be another British innovation lost.

[ProDave]

36 minutes ago, Alphonsox said:

 

I disagree - Sunamp seem to be loosing their USP in the domestic market. If they cant reliably capture excess renewable energy then they move to being just another Megaflow competitor.

But one you can't sensibly use with an ASHP.....

[Ed Davies]

1 hour ago, PeterW said:

doesn’t it miss the point though of not being able to use it to take excess PV without mucking about ..?

 

1 hour ago, Alphonsox said:

I disagree - Sunamp seem to be loosing their USP in the domestic market. If they cant reliably capture excess renewable energy then they move to being just another Megaflow competitor. 

 

Do we have any actual evidence that this thing about not accepting PV until discharged to some silly amount (50 or 90%) has anything to do with protection from the PCM overheating? That seems to be just an assumption being made here. Perhaps there's another reason why they're insisting on these deep discharges. Perhaps it's a good reason but if it is then indeed that's a serious problem but it seems more likely to me that somebody just hasn't thought through the controller design sensibly.

 

Edit to add: my suspicion is that they decided on the 50% discharge so that any source they called for heat from, like an ASHP, would have a nice long run to work efficiently and they simply forgot that PV only works when it works.

Edited December 2, 2018 by Ed Davies

[Jeremy Harris]

1 hour ago, scottishjohn said:

so what you are saying is it should never have been released then ,but they have made the pcm case thinner than the first one from what i read .

there should be no swelling of the pcm case -so they have made it too thin--any way its basically not fit for purpose -

and if you remember i said this very early on when i referred to "tombstone technology " as they called it in the aero industry 

-i,ll revisit this thread in a years time and see what they are like then  once production is moved to china !!.which it will be , nothing more certain.

 

No, the case is the same gauge aluminium as the SAPV.

 

I'm near-100% certain that this is down to a lack of proper production engineering.  Remember this is a technology start-up, working in close partnership with academia.  They have had a fair bit of seed funding too.  I doubt they have really done a proper cost-engineering job on the product yet.  If they had then the first lesson they would have learned is "right first time".  That's a really fundamental principle, that every business needs to uphold to be profitable.  Gaining a poor initial reputation from some fundamental production engineering and design problems would drive every bean-counter to distraction.

[Jeremy Harris]

8 minutes ago, Ed Davies said:

 

 

Do we have any actual evidence that this thing about not accepting PV until discharged to some silly amount (50 or 90%) has anything to do with protection from the PCM overheating? That seems to be just an assumption being made here. Perhaps there's another reason why they're insisting on these deep discharges. Perhaps it's a good reason but if it is then indeed that's a serious problem but it seems more likely to me that somebody just hasn't thought through the controller design sensibly.

 

Good point.  No, it's an assumption, but there is no doubt at all that the UniQ that I have now is far less capable at effectively utilising excess PV generation than the Sunamp PV we used to have.  There has to be a reason for this, as the efficient storage of excess PV generation was the USP for the Sunamp range of products at the time I initially  took the risk and chose to invest.

[Eileen]

Presumably even the most basic QA function would have caught this. Obviously there was a lot of concentration on cycling the PCM materials to death, but maybe not so much on testing the fully cased production version in a real life situation.

 

Someone mentioned the bean-counters - from my experience in product engineering (software in this case) it was hardly ever product design that was impacted by financial imperatives, but it was always quality assurance that was endangered because of the demand to "get it shipped"! And of course in the software area you can see that now that it's much easier to get updates out there ("A new version of XXXX is ready to upload") the quality criteria have clearly been relaxed since the good old days when it meant shipping a shed-load of DVDs to customers.

[Onoff]

Is there an issue with the UniQ and ASHP?

 

I only ask as I've recommended SA to three people;

 

Two wanted it specifically to store excess PV where they're currently exporting it to the grid.

 

The third has already specified it on his new build plans for use with an ASHP but no PV.

[newhome]

I recommended it to someone too who has one stored at Sunamp until they are ready to install it. How do I tell him that the case may become deformed and it won’t store all of his excess PV! 

[Onoff]

On 19/11/2018 at 08:44, scottishjohn said:

yes we hope its minor --but i question why this expansion +contraction of the internals has not been allowed for in the case  construction that contains the active ingredients--

could this be the chineese involvment trying to slim down costs?

anyway time will tell

-how long is the warranty ?

 

I kept digging for a Chinese link:

 

https://interface-online.org.uk/case-studies/sunamp-heat-batteries

 

"In 2017 Sunamp and the University of Glasgow's School of Engineering have partnered on a £2 million project linked to clean power and heat generation from the China-UK Research and Innovation Bridges programme, a joint UK China initiative under the Newton Fund developing solutions for agri-food, energy, healthcare, and urbanisation".

[Triassic]

Having read this thread I’m now wondering if it’s too late to cancel my order and go back to using a thermal store that will accept PV input in my design!

[Onoff]

3 minutes ago, Triassic said:

Having read this thread I’m now wondering if it’s too late to cancel my order and go back to using a thermal store that will accept PV input in my design!

 

Have you paid by credit card? 

 

If you bought based on the concept of the old unit I can't see why not. Maybe ask SA for a statement to confirm or otherwise the many assumptions being made within this thread. If they refused to give it I imagine it would be all a credit card company would need to refund you if they wouldn't anyway.

[Onoff]

The conspiracist in me wonders if these issues with the product have been influenced by an outside party, with maybe a "Grand Plan".

 

Customer base loses confidence, figures go down and the product moves abroad...

 

Still no comment here from SA???

 

[scottishjohn]

7 hours ago, newhome said:

I recommended it to someone too who has one stored at Sunamp until they are ready to install it. How do I tell him that the case may become deformed and it won’t store all of his excess PV! 

the obvious answer is send them a link to this thread and then the make their own decision