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SunAmp : Snog, Marry, Avoid?


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1 hour ago, JSHarris said:

From what I've seen, it's not that hard to get ST systems to this sort of temperature when they stagnate.

 

Yep, friend had a single largish flat-plate collector. He'd switched off the electrics to do some work on a sunny day having not given the matter sufficient thought which resulted in the pressure going way up and the temperature reaching 130°C before the plastic pipe burst, squirting hot water around. Fortunately nobody was in the way.

 

Yes, the “professional” plumber had installed plastic pipe right up to the panel. You shouldn't be using soldered joints within a metre or so of the panels, let alone plastic.

 

You'd definitely not want to rely on just the controller to make sure that that sort of temperature water could never get to the Sunamp. E.g., if the power went out for a while then came back with the panels hot.

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6 minutes ago, Ed Davies said:

 

Yep, friend had a single largish flat-plate collector. He'd switched off the electrics to do some work on a sunny day having not given the matter sufficient thought which resulted in the pressure going way up and the temperature reaching 130°C before the plastic pipe burst, squirting hot water around. Fortunately nobody was in the way.

 

Yes, the “professional” plumber had installed plastic pipe right up to the panel. You shouldn't be using soldered joints within a metre or so of the panels, let alone plastic.

 

You'd definitely not want to rely on just the controller to make sure that that sort of temperature water could never get to the Sunamp. E.g., if the power went out for a while then came back with the panels hot.

nothing but copper in solar thermal   and compression fittings 

simple extra temp switch which by pass the controller for emergency sorts that 

if copper then stagnation is not a problem -my problem was i was continuing to circulate --so foam insulation melted and dripped off the piping and thats 170-180c to do that 

power cut would not  be a problem cos anount of water that would be hot would son drop intemp before it got to sunamp --very little volume in panel 

Edited by scottishjohn
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1 hour ago, scottishjohn said:

thats part of your solar controllers job

you set max tank temp  and also max panel temp --the temp of water leaving the panel .

it turns off if too high or you can divert to to a heat dump -like an old radiator somewhere   --I like that system better as you do not get high stagnation temps in the panel which will damage panel over time if a regular occurrence.

It is unlikely if you have matched panel size with storage tank-- that was my mistake on old system 

300litre tank and 2x20 evac tubes--good day you got boiling tank by lunch time even though it the same tank had an UFH coil in it

add to that the system was supplied with a PLASTIC  air separator --which when temp sensor went faulty  some years on it melted

then panel temp got that high that it melted foam insulation from the copper pipes .

partially my fault trying to get max from it so did not have high temp cut offs set ,but  who would spec a solar thermal with anything plastic in it !!

but it shows how much heat  you can get if tank is not big enough for panels you have

one 20-30 evac tube panel is plenty for a 300 litre dhw tank 

better to have too much and dump it ,than be struggling on a winters day for heat 

 

 

Boy are you in for some questions when I do mine! :)

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1 minute ago, scottishjohn said:

no problemo 

 

 

Skipping through your comments...30 tubes on a presumably clear winters day will feed a 300L then with a useful amount of heat? 

 

What about overcast days? I've heard you still get heat input with ST.

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Just now, Onoff said:

 

Skipping through your comments...30 tubes on a presumably clear winters day will feed a 300L then with a useful amount of heat? 

 

What about overcast days? I've heard you still get heat input with ST.

yep -feel your roof on an overcast day --still gets warm 

maybe if more questions -you should start another thread before we get  in bother 

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You won't get much meaningful heat on overcast days. It's difficult to estimate output as it depends on insolation, ambient temperature and store temperature, but they are only reasonably effective in bright light.

 

Some examples, I have 3.8kW peak PV on the roof and 120 evacuated tubes, installed at about 45 degrees tilt and facing WSW.

20th March PV 20.3 kWhr, ST 31.5 kWhr (good sunny day)

17th March PV 12.7 kWhr, ST 16.2 kWhr (bright day)

16th March PV 3.9 kWhr, ST 2.1 kWhr (dull day)

7th March PV 2.5 kWhr, ST 0 kWhr (very dull day)

 

Over the winter months you can expect very little energy. In January we had 20 days with no energy collected and only 3 with more than 3kWhr collected.

 

Put it another way, January was one of the dullest months we've had since 2012, when the data collection started.

PV averaged 2.63kWhr a day, ST 1.09

February was one of the brightest winter months we've had.

PV averaged 9.42kWhr a day, ST 10.88

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55 minutes ago, billt said:

Some examples, I have 3.8kW peak PV on the roof and 120 evacuated tubes, installed at about 45 degrees tilt and facing WSW.

 

Interesting info, thanks for sharing.

 

How much would it cost to have 120 evacuated tubes supplied and installed?

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4 hours ago, billt said:

You won't get much meaningful heat on overcast days. It's difficult to estimate output as it depends on insolation, ambient temperature and store temperature, but they are only reasonably effective in bright light.

 

Some examples, I have 3.8kW peak PV on the roof and 120 evacuated tubes, installed at about 45 degrees tilt and facing WSW.

20th March PV 20.3 kWhr, ST 31.5 kWhr (good sunny day)

17th March PV 12.7 kWhr, ST 16.2 kWhr (bright day)

16th March PV 3.9 kWhr, ST 2.1 kWhr (dull day)

7th March PV 2.5 kWhr, ST 0 kWhr (very dull day)

 

Over the winter months you can expect very little energy. In January we had 20 days with no energy collected and only 3 with more than 3kWhr collected.

 

Put it another way, January was one of the dullest months we've had since 2012, when the data collection started.

PV averaged 2.63kWhr a day, ST 1.09

February was one of the brightest winter months we've had.

PV averaged 9.42kWhr a day, ST 10.88

and what were the temps on the solar thermal on those days ? do you have that info?

 

WSW may work ok for pv --but thermal tubes definately need to be closer to south  if possible 

flat plate may work ok when not direct to the sun ,but again they are no where near as good in our latitude as evac tubes if both were  facing right way

,yes you can swivel the tubes in the frame to get better direction ,but only so much or they will be shading each other  

you say you have 120 tubes --what size storage tank?

cos I could  boil my 300 litre tank with 40 tubes  quite often in summer  if i wanted to and that was with a morning tank temp at bottom --using it for ufh --of 20c and top tank temp of 30c. and getting a  decent temp drop on return  to panels

 

Edited by scottishjohn
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I was wrong about the orientation, it should have been SSW, about 15 degrees W of S.

The tank is 2,500l; the ST has had it up to 95C or more after several days of unbroken sun with not much hot water draw off.

 

On the 20th of March the tank started at 36C

On the 17th of March the tank started at 37C

On the 16th of March the tank started at 38C

 

The point is that in overcast conditions there is little energy available and the non linearity of solar thermal systems means that the harvest-able energy drops off rapidly. IOW in effect they don't work in dull conditions.

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On 20/03/2019 at 19:27, JSHarris said:

First off, I'm not an expert, by any stretch of the imagination. 

 

Secondly, @Barney12's problems are well documented here, as are those experienced by @Eileen, so there are at least three members here who've experienced some problems/issues with their Sunamps. I think that @readiescards may also have had a unit replaced by Sunamp.  I think we may have around half a dozen or so members that have the newer model Sunamps, so it would seem that perhaps 50% of them, maybe more, have experienced some problems.

Yes one of my two Sunamps has been replaced as I refused to accept the bulging case on the PCM58 unit as being good long term. Also one of the first controller units was incorrectly sent. Sunamp have been good at rectifying these issues in a timely manner.

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On 22/03/2019 at 20:40, billt said:

I was wrong about the orientation, it should have been SSW, about 15 degrees W of S.

The tank is 2,500l; the ST has had it up to 95C or more after several days of unbroken sun with not much hot water draw off.

 

On the 20th of March the tank started at 36C

On the 17th of March the tank started at 37C

On the 16th of March the tank started at 38C

 

The point is that in overcast conditions there is little energy available and the non linearity of solar thermal systems means that the harvest-able energy drops off rapidly. IOW in effect they don't work in dull conditions.

I have to say i think who ever specified the tank got it wrong -total litreage --not a problem but all in one tank --that  limits  you to when your sloar can work and will shorten the numberr of hours it can wok if it has to be above main tank temp 

3 smaller tanks with different target temps and it would work  much better

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  • 2 weeks later...
30 minutes ago, Barney12 said:

 

 

I have to say they have been trying hard to understand and sort things lately; a new controller is on its way to me that has a fix for the charge threshold issue.  Interesting that the advert mentions optimising controls (my highlight) as this tends to suggest that they recognise that the control system isn't well optimised at the moment, something that's borne out by my recent correspondence over the charging issue.

 

Quote

Controls Engineer

As a Controls Engineer with us you will be involved in product and engineering controls for all Sunamp products and for specific Sunamp HVAC packages and projects, product documentation, applications, product controls development, and regulatory code compliance.

Your main responsibilities will be:

  • designing and developing new control systems to deliver algorithms to optimise charging times to optimise the running of the Sunamp Heat Battery, the package it is working with and the energy tariff.
  • design and develop control systems to optimise the running of all Sunamp products
  • testing, maintaining and improving existing systems
  • writing computer software code and test procedures
  • Perform complex installation, testing, upgrades, start-up/commissioning, maintenance, and troubleshooting of electronic components in accordance with industry standards.
  • working collaboratively with internal design engineers, project managers and other internal staff
  • liaising with clients, suppliers, contractors and relevant authorities
  • providing controls to projects within cost and time constrained environments
  • understanding and ensuring compliance with relevant health and safety regulations and quality standards
  • analysing data and presenting findings in written reports, creating content for engineering documentation for distribution to internal and external customers.
  • Works safely and promotes a safe work environment for others.

 

If the glitch with the way that charging is controlled is resolved then I have to say that I think the product will be very good.  Since I've been resetting the controller every day it's worked flawlessly, and has been utilising excess PV generation perfectly, just as a hot water tank would, but with much lower losses.

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@JSHarris What's the timeline for your new controller? My UNiQs have gone back once already so ideally I want them back with new controllers that actually do the recharge as required! So looking forward to your testing feedback when you have installed your new controller!! ?

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1 hour ago, oranjeboom said:

@JSHarris What's the timeline for your new controller? My UNiQs have gone back once already so ideally I want them back with new controllers that actually do the recharge as required! So looking forward to your testing feedback when you have installed your new controller!! ?

 

It should be with me next week, I believe.  I'll swap the controller over as soon as it arrives, and with luck should be able to tell within a few days if it reliably goes into charge acceptance mode after we've used the shower in the morning.  The existing controller would fail to charge around 30% of the time, so I need to test it for a few days to be reasonably confident that it works OK all the time.

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1 hour ago, JSHarris said:

 

It should be with me next week, I believe.  I'll swap the controller over as soon as it arrives, and with luck should be able to tell within a few days if it reliably goes into charge acceptance mode after we've used the shower in the morning.  The existing controller would fail to charge around 30% of the time, so I need to test it for a few days to be reasonably confident that it works OK all the time.

Thanks Jeremy - we'll be looking forward to your review....as will Sunamp I am sure!

 

3 hours ago, ProDave said:

Interesting.

 

I wonder if they would consider a consultancy rather than a full time position?  

Hope they have budgeted for over-time!

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