Samsung Gen 6 8kW Efficiency

glyn.hudson · 2022-12-18T00:48:40.370Z

CoP:

The difference is only 1-2º, whereas it should be 5º, so it sounds like something is up with the unit.

This low dT is probably because the UFH cannot dissipate the heat due to the insulation from the wood flooring. You could try reducing the pump speed which will increase the dT. But don’t worry too much about dT, most systems only get dT5 at max output. I usually get a dT of 2-3C, dT is usually lower with UFH because of the larger surface area.

What size are your UFH pipes and what’s the spacing?

borpin · 2022-12-18T13:49:41.717Z

glyn.hudson:

This could be a significant issue, I recently helped a friend that was having heat pump issues with UFH and wood floor.

I didn’t make that mistake twice. Second house, UFH is tile covered with the odd rug or 2.

CoP · 2022-12-20T19:32:55.383Z

The UFH pipes are 15mm and spaced around 150mm apart.

CoP · 2022-12-20T19:36:18.259Z

Interesting update - Samsung came round to have a look at the unit and were baffled at how inefficiently it was performing. They spent most of the day with me and were satisfied with the setup. The issue seemed to be that the unit was just not transferring heat to the water, so the delta T was only about 1 degree.

They have updated the firmware and also accidentally released some of the refrigerant when testing the pressure. It was quite spectacular and the poor engineer was squirted all over with the stuff. Funnily enough, something seems to have improved the efficiency somewhat as the CoP is now well over 2 (I appreciate the weather has been very warm), but it rarely achieved over 2 previously, even in quite warm weather.

CoP · 2022-12-20T19:37:24.504Z

glyn.hudson:

This could be a significant issue, I recently helped a friend that was having heat pump issues with UFH and wood floor. After removing the wood they experienced a significant increase in performance since they were able to run lower flowT.

The wood floor is definitely an issue, but I’m not sure it is the main one.

CoP · 2023-02-02T09:39:40.991Z

A very interesting update for those who are curious about this: Samsung sent an engineer to check the refrigerant pressure yesterday and found that it was higher than it should have been (despite the earlier incident with the accidental release of refrigerant). He replaced the gas to a lower pressure. This seems to have made quite a drastic difference to the efficiency. Yesterday before the intervention the CoP was around 2. After the intervention the CoP was 4! Not terribly scientific, but the temperature was very similar and the unit has never achieved such a high CoP before.

TrystanLea · 2023-02-02T11:55:29.019Z

Hello @CoP did Samsung send out an engineer free of charge? just asking for Ian on the other thread?

CoP · 2023-02-02T14:06:14.397Z

I reported these issues over the previous couple of years, but never had a satisfactory response. The visit was triggered by the changeover valve getting stuck before Christmas. The software needed to be updated, which they did. On that visit, the engineer had a good look and realised something was up. So no, no charge, but I’m not sure they would send somebody for free automatically.

glyn.hudson · 2023-02-02T18:05:02.313Z

That’s great news! It’s a bit worrying that you were originally sent a unit with the incorrect refrigerant pressure. Hats off to Samsung for sending an engineer who managed to resolve the issue

Madsen68 · 2023-12-08T16:15:52.550Z

Hi
So nice to find you case here…
I have a 8kw - installed February 2023 and I have not had COP above 3,1 at any time during that period. Does not matter if its 20 degrees celsious outside or 7, or 0 - allmost same cop between 2,2 and 2,8
I have had the company here several times without any solution.
I will call them asap and get the pressure of the gas mesured.

How is your pump running now - any issues?

thanks

CoP · 2023-12-08T16:32:17.758Z

Sorry to hear you are struggling. A CoP of 2 is more than mine was at before it was depressurised!

Now it’s running beautifully. In warmer weather the CoP is well over 5. Standard in cold weather is above 3.

SarahH · 2023-12-08T16:45:36.865Z

Hi Arne, and welcome to the discussion group.
This thread originally related to a Samsung Gen6. Is that what you have?
I’ve recently installed an 8kW Samsung Mono Quiet (AE080BXYDEG/EU) so slightly different, but have spent the last 3 months optimising the setup, and have gleaned quite a bit of additional info from Samsung (plus a bit or reverse engineering using my Chem Eng background).
I’m now getting CoPs within 20% of Samsung publicity data. Happy to share details if you are interested…
Sarah

Madsen68 · 2023-12-08T17:13:31.618Z

Hi
I also have the Mono EHS Quiet - 8kw
Experiences cop below 3 - winter ands summer - my best cop was 2,93 with outside temp at around 22 degrees Celsius. Should have been above 4, at least.
At 7 degrees outside I get around 2,4-2,6
At 0 degrees I get around 2,2
So my guess is that I have similar problem to that thread - hopefully.
Settings should be very fine tuned to best possible and I also run with a beta FW that should increase Delta T from 1 degrees to 5 degrees. This will also be implemented in FW update in the beginning of 2024, so we will be able to adjust Delta T from 0 to 7 degrees.

SarahH · 2023-12-08T17:56:05.365Z

How are you calculating your CoP? (i.e. how do you establish your ASHP heat output and power consumed?)
Do you have a MIM-E03EN controller?
What do you mean by “FW”?
Sarah

Madsen68 · 2023-12-08T19:11:26.133Z

Hi Sarah

COP is genrated Mwh (measured by a Kamstrup heatmeasure device with flow and temperature sensors) divided with actual used kWh.
Yes and knows it in and out…
FW = Firmware on the unit.

Madsen68 · 2023-12-08T21:54:32.163Z

Hey CoP

Just realised you have Gen 6 and I Got the new EHS Quiet 8 kw - anyway, hope to find the pressure also Can be the reason for it to fail In performance.
Thx m8
Arne

SarahH · 2023-12-09T09:52:14.732Z

Thanks Arne. I have no monitoring kit beyond my PV inverter software which just gives me instantaneous total household power consumption (i.e. not just the ASHP, though the latter is typically 90%+ of the total so it’s good backup data).

Have you checked your Kamstrup accuracy for generated energy? As I’m sure you know, you can estimate duty using ASHP flow, inlet and outlet temps (all available on the MIM display) using Q (kW) = m (kg/s) * Cp (kJ/kg/degC) * dT (degC). Obviously you’ll need to convert vol flow from the MIM to mass flow. At startup each day my flow is about 27lpm and my dT is about 5degC, so my Q is 27 lpm * 1.02 kg/l (I have glycol) * 3.93 kJ/kg/degC * 5 degC / 60 s/min = 9 kW. On a cold day the MIM shows ASHP power consumption of about 2.5 kW, so that’s a CoP of about 3.6.
Do you take duty cycle into account? Once my ASHP exit temp (Tw2) hits Water Law setting it cycles 2-3 times per hour so the average power consumed may be as little as 1/3 the measured instantaneous consumption.
Have you checked your heat generated and power consumed numbers against those in the Samsung ASHP Data Book? I didn’t discover this gem of a document till quite late on (it’s available for download from the Midsummer Wholesale website if you don’t already have it - check out Table 2-9 on p28). This might help you test which of power consumed or heat generated are anomalous (if not both). I’m finding that my numbers for both are a little higher than the Table, but the CoP is similar once I divide one by the other.

I’ll be interested to hear how your numbers compare with Samsung’s…

Sarah

Madsen68 · 2023-12-09T11:32:50.684Z

Hi Sarah

I have not checked the Kamstrup for its accuracy - hope the installer knows whats he is doing and rely on that When thats said, the Kamstrup delivers allmost the same amount of generated energy as the MIM shows - difference is below 5% - Kamstrup shows a bit more energy produced, which I find plausible.
I have a flow around 18 l/min and also dT around 5 degC
My calculation rely on the Generated Mwh from the Kamsrup up against my used kwh readings on my measuredevice on Power input to the house - here I have a total consumption, only for the ASHP.
SCOP from the day of installation of the Kamstrup measuredevice is:
Used kwh: 1857 kwh
Production Mwh: 4,042
4,042*1000= 4042 kwh
4042/1857= 2,18 SCOP
Period: 9/6 - 9/12-2023

If I do the same for one day, without DHW (Turned completely off) it looks like this:
Used kwh: 17,8
Production kwh: 48,9
COP: 2,75
Average temp.: 8,2
According to the Data book at 7 degrees - should be HC: 8 - PC: 1,6 at LWT: 35 degrees
At 7 degrees I run around 30-33 degrees, so not even up at 35.

Am I drawing a wrong conclusion on this, saying I am missing at least 5-2,75= 2,25 in COP that day.

I would like to learn how to do your calculation - I have pictures of the following:
KAMSTRUP READING:
1488,08 m3
7014 h
Current temp: 36,54 (t1)
Current temp: 33,87 (t2)
2,71 k (t12)
52100 C m3 (E8)
48706 C m3 (E9)
1084 l/h
3,3 kw
4,048 Mwh

Used kwh: 1857 kwh
Period: 9/6 - 9/12-2023

Todays reading from midnight (12 hours)
Used today, until now: 10,3
Production until now: 28,6
L/min: 17,8

Sorry, but a bit confused over this and how to do it correctly

Is it to much to ask… To make an éxcel file and point me to which input is needed, to read out exact COP of a day or SCOP, for that matter - or can I find this online somewhere…

Thanks - you have allready been very helpfull

CoP · 2023-12-09T12:11:21.238Z

Hi Sarah, could you share a link to the data book please?

Ian_Calderbank · 2023-12-09T12:49:10.598Z

If a day at 8.2C, used 17.8kwh and produced 48.9 kwh, then yes the COP was sub 3. and you’re running at a good low flow temp of 33. So it should be able to do COP of at least 4 at those temps. 5 is a stretch, needs a really super-optimised system. But a COP of 2.25 implies something is wrong.

Do you have a way to automate frequent readings of your meter this is very helpful to track what is going on? many of us do this and log it to the emoncms system.

rather than focusing on the metering, can you explain your system setup, perhaps draw some diagrams? buffer? LLH? TRV’s? zones? or fully open single loop?