SunAmp : Snog, Marry, Avoid?

[epsilonGreedy]

13 hours ago, Russdl said:

We love our Sunamp and are definitely in the ‘marry’ camp

 

 

When you say "marry" do you really mean welded to the melted circuit board?

[Onoff]

14 hours ago, Russdl said:

Any other ideas as to why that bit of wire and gubbins would have failed?

 

 

At a guess @Jeremy Harris has stopped ad hoc consulting for them? ?

 

Weren't the early models "better"? 

[joe90]

8 minutes ago, Onoff said:

Weren't the early models "better"? 

In Jeremy’s opinion, yes.

[Onoff]

Just now, joe90 said:

In Jeremy’s opinion, yes.

 

Let's be honest, that counts for a lot.

[Russdl]

It was Jeremy’s early reporting on his SunampPV that grabbed my attention way back when. 
 

His warts and all explanations of the problems he encountered with the second generation Sunamp was hugely informative and not enough to put me off.
 

I know there are some on here who have had problems and would probably launch their Sunamps off a cliff, if only they had the strength to move them.  I guess there are others here who are having no issues?

 

Despite our little er, hiccough, I’m still smitten.

 

Maybe not if it fails again though. 

[ToughButterCup]

So far, so good with us. Well behaved little unit. 

[Russdl]

@ToughButterCup very pleased to hear that ?

[Triassic]

I’m in the Avoid camp, sorry, Too many false starts and hiccups. 

[joe90]

29 minutes ago, Triassic said:

I’m in the Avoid camp, sorry, Too many false starts and hiccups. 

me too, as you know I am a Luddite ?. Jeremy went down the sunamp route because of overheating from his DHW tank and had all sorts of problems which he advised the manufacturer how to fix (which I couldn’t) I don’t suffer from overheating and I like tried and tested stuff, perhaps in the future!!!

[SteamyTea]

31 minutes ago, joe90 said:

Jeremy went down the sunamp route because of overheating from his DHW tank

His original design was not very good, one of those combined DHW cylinders with the F&E on top, then sprayed with a bit more foam.

 

I just think they are very expensive for what they are.  Useful in a tiny house, or flat, but only if heated with electricity only.  As soon as renewables or gas come into the equation, it is a very expensive option.

Edited April 9, 2021 by SteamyTea

[Iceverge]

I think it was a coil in tank thermal store. These need to be kept very hot to produce usable amounts of DHW with consequent high losses. Not really suitable for low energy houses. 

 

Shame really as I like the simplicity. 

[joe90]

10 hours ago, Iceverge said:

I think it was a coil in tank thermal store. These need to be kept very hot to produce usable amounts of DHW with consequent high losses. Not really suitable for low energy houses. 

Was it?, I may be wrong but how was Jerry going to get very hot water from an ASHP? If so that’s why his losses were high (and the cupboard door buckled ?)

[Onoff]

Jeremy had problem(s)/Jeremy found solution(s).

[joe90]

5 minutes ago, Onoff said:

Jeremy had problem(s)/Jeremy found solution(s).

yes but I do not have his knowledge to find my own solutions which is why I mourn his leaving us ?

[SteamyTea]

3 minutes ago, joe90 said:

yes but I do not have his knowledge to find my own solutions which is why I mourn his leaving us ?

Jeremy soon found out that KISS works best.

 

 

[pdf27]

2 hours ago, joe90 said:

Was it?, I may be wrong but how was Jerry going to get very hot water from an ASHP? If so that’s why his losses were high (and the cupboard door buckled ?)

Wasn't it also an unventilated cupboard?

[Triassic]

17 hours ago, pdf27 said:

Wasn't it also an unventilated cupboard?

That’s why the spare outlet on the MVHR system I will be used to ventilate the plant room containing my cylinder.

[volcane]

21 hours ago, joe90 said:

Was it?, I may be wrong but how was Jerry going to get very hot water from an ASHP? If so that’s why his losses were high (and the cupboard door buckled ?)

 

I think the acre of PV panels also helped with the high thermal store temperature

 

After multiple attempts and many hours I abandoned my quest to install a Sunamp unit and am going with a split low temperature ASHP with a 500 litre UVC.

[MikeSharp01]

21 hours ago, joe90 said:

Jerry going to get very hot water from an ASHP

Didn't he use Eltron in line water heaters to boost the temp on demand he found that they would add the few degrees he wanted to the tank output.

 

[SteamyTea]

16 minutes ago, MikeSharp01 said:

Didn't he use Eltron in line water heaters to boost the temp on demand he found that they would add the few degrees he wanted to the tank output.

 

He fitted one, but found he did not need to use it much, if at all.

Was more as an insurance I think.

 

I don't know why people find DHW co complicated.

You either store it or not, if not, then you heat when needed.

[PeterW]

18 minutes ago, SteamyTea said:

 

I don't know why people find DHW so complicated.

You either store it or not, if not, then you heat when needed.

I think the main issues are that in the 60- early 90’s, everyone had a hot water tank from either a back boiler or “the immersion” that was small, and the memory is of water running out. 
 

Then in the 90’s the combi boiler took hold and it was “all you can use hot water” but the pressure was crap. 
 

Megaflo came along and tried to fix some of the problem, and then UVCs took hold properly so we have mains presssure hot water, but a fair amount of it. 
 

The issue now is switching to new heat sources, and there is always the fear of running out of water as people have got used to the endless nature of a combi, but want the flow of mains pressure, with the economy and “eco credentials” of the ASHP... its the holy grail of DHW ..!

[ProDave]

28 minutes ago, SteamyTea said:

He fitted one, but found he did not need to use it much, if at all.

Was more as an insurance I think.

 

I don't know why people find DHW co complicated.

You either store it or not, if not, then you heat when needed.

The only "complicated" thing with a small ASHP and UVC is re heat time.

 

Following on from Peters comments above, people were used to an UVC from a gas or oil boiler that would re heat in not much more than half an hour, so running out of hot water is not an issue.

 

A small ASHP takes very much longer to re heat a depleted UVC. Add in the fact that the UVC will probably be larger due to the water being stored at a lower temperature.  It's therefore quite possible with multiple showers to run out of hot water before the ASHP is able to re heat it.

 

I have "solved" that as I now have Jeremy's old Steibel Eltron instant water heater in line with the UVC output.  It is set at a degree or 2 lower than the UVC temperature so normally it does nothing but if the tank starts to run cold it will boost the temperature.

 

One thing i would say when ordering a tank for an ASHP is get some extra thermostat pockets installed.  I forgot to specify that when I ordered my Telford 300L heat pump tank so I only got the 2 default pockets.  Even the lower one of the 2 is about 1/3 of the way up the tank.  So the tank could be down to only 200L of hot water in it before the ASHP even knows it is getting depleted.  If I were ordering a cylinder now I would want an extra thermostat pocket or 2 lower down, say one at immersion heater level and one just a bit above so you could experiment with which works best.

[joe90]

I too bought a stiebel Eltron in case it’s needed, still in its box in the loft. A agree with @ProDave about stat pockets but have found the upper one of mine is fine fir the two of us but can move it to the lower one when guests descend (hopefully soon ?‍♂️).

[SteamyTea]

20 minutes ago, PeterW said:

I think the main issues ........................... its the holy grail of DHW ..!

 

[TerryE]

I've got 2× SunAmp PVs (the early models):

• Mechanically well engineered.
• Compact and very low heat losses.
• We've never had a problem with the instant heat rates.
• The control circuit boards have some fundamental design flaws which have never been addressed (mainly no decent 240V isolation and 12A traces totally inadequate, overheating of the main 12A relay).  I've had 2 board failures in the first 2 years of operation.  Not good.

I really like the form factors and the functionality.  My long term intent is to keep them but dump the internal controller boards and replace them with some direct control.  (I already have an dedicated RPi which does the CH and DHW control, and it would be straightforward to control the SA heaters and pumps direct from this.)

 

The thermal density and energy release characteristics of a PCM store are very compelling IMO, we just need a competent supplier.