Sorry to bother you again, but I still have a niggling doubt about Samsung's Weather compensation.
I still find it difficult to believe that the Samsung Heat Pump uses Weather compensation under the " not used " option 0 of Field bit 2091.
My System , for example, allows me to set the Water Temperature Offset and measure the resulting pipe Water Temperature but only when using field bits 2091 with Water apps 1,2 or 3.
My Samsung Instruction manual makes no mention of Water Law Weather compensation , WL, for the "not used" option..
How do you know it is working without a control or display?
A visiting French Samsung Engineer, a strong advocate of Weather compensation, nonetheless freely admitted to "not understanding" the differences between 2091 Motor App 1,2 or 3.
His opinion was that "it made little difference whither Motor App 1 , 2 or 3 was used, but use them nonetheless".
He left , saying that "weather compensation saved between 7% and 10% Energy".
I may be mistaken , but my understanding is that the "Cycle time " is a function of the Water Volume contained in the Water pipes connecting the Heat Pump to my Heat Exchanger.
Hi Ian, yes you are mistaken. The water volume in the primary loop with a heat exchanger is always going to be small. This a quote from Graham Hendra's linkedin article on secondary flow: 'In my system I have a total of 150 litres of water in all the pipes and radiators, the primary circuit only holds about 25 litres the rest is in the secondary.' The main determinant for cycling is the volume in the secondary circuit.
Samsung also say that " Samsung Heat Pumps Do not "normally" require a Buffer tank, however, if the volume is less than 20 L a Buffer tank will be required
How do you know it is working without a control or display?
Very easily. When I view my heating display, I can see the flow temperature and when it is -5C outside it has a flow temp of approx 45C and when OAT is 5C, the flow temp is approx 35C, so it is quite clear that weather compensation is operating (see photos). Weather compensation does indeed save you money compared with a fixed flow temperature. Weather compensation is running whether you choose 2091 0,1,2,3 or 4
Samsung-Dallium advised that a Buffer tank should be installed on my system " to prevent winter freezing ".
The Samsung controller dumps water from the Buffer tank during cold winter nights without consuming Electricity.
My Buffer tank successfully and verifiably protects against Winter freezing.
I no longer have a buffer tank. The anti freeze function on my 12kW Samsung takes heat from my DHW cylinder. I'm not sure what it used to do before the buffer tank was removed, but I suspect it did the same.
Personally, I would like to abandon the entire system, returning to a far simpler One water loop system without Heat Exchangers, Volumisers or secondary pumps , Expansion vessels and PRV's.
Have you any plans to do this? I'm sure that is the right way forward, but as stated before, don't get rid of the expansion vessels or PRVs!!
Many thanks mike for your excellent corrections to my understanding. I stand corrected again.
Given the previous performance of my,
a) my "installer" ,now STRUCK-OFF for the Third Time in Two Years.
b) The NIC who now say that " You are not going to like this but ..................................................Nothing can now be done....good luck!".
c) Telford, who repeatedly advised "that all their tanks should be installed with a 50 L Buffer".
d) A coterie of "Experts" who issue conflicting and uncosted advice .
I must be very wary of spending any more money!
Sorry, but my definition, and observation, My Cycle Time is that between
a) When the Primary Pipe Water Temperature is greater than Water Law Trigger Temperature, WLTT,
AND
b) The Time when the Pipe Water Temperature dips below the End of Cycle Water Law Trigger Temperature, EOCTT,
i.e. Cycle-Time = Time between (WLTT firing - EOCTT firing )
Where
The Water Law Trigger Temperature = Field bits 202,203 + Water Law Thermostat Control.
AND
The End of cycle Water Law Trigger Temperature is the Water Law Trigger Temperature -(minus) the Hysteresis.
With the Hysteresis differing between 2091 Bits 1,2 and 3.
As I have said , many times before, "I might be wrong" but the Cycle Time defined above corresponds exactly to that measured by my Power Meter.
I agree completely , the MCS along with it's fellow "Charities" the NIC and now the RECC, should, at least , face competition .
The MCS description of itself as a "Registered Charity" is insulting!
When I asked the MCS for a statement about their status I was told that "the MCS is a private company , registered as a Charity because of it's Educational commitments to the public , Energy saving"!
I , now in my 25 month, of trying to get an affordable Heat Pump , am furious with the MCS for re-instating my "installer", STRUCK-OFF by the NIC, on THREE occasions during the last 18 months.
The MCS is ONLY concerned with their annual subscription fees .............extracted from their members , the "installers"!
The MCS is a private company masquerading as a "charity".
Sorry to do another Viktor Meldrew impersonation , but, to cool myself down I have been devising other tests for my "Short cycling "problem.
My Heat demonstrates remarkable "Short Cycling2 shown in the terrifying graph of Heat Pump power, Kw....
In trying to measure , and quantify the extent of "Short Cycling" I have taken the Fast Fourier Transform, FFT of the Heat Pump Power
The FFT shows Power in each sine wave component , as a function of Frequency......
With the FFT ,"Short cycling" is shown in the peak at 150 Hz with the First Harmonic shown in the second peak at 300 Hz . The Succession of Peaks at regular intervals confirms the Square wave nature of " Short Cycling".
This restrains and contains my anger with the performance of this Heat Pump , now ( March 2024) only heating one room , and that with the aid of a 1.5 kW Electric fire!!
Sorry to do another Viktor Meldrew impersonation , but, to cool myself down I have been devising other tests for my "Short cycling "problem.
My Heat demonstrates remarkable "Short Cycling2 shown in the terrifying graph of Heat Pump power, Kw....
In trying to measure , and quantify the extent of "Short Cycling" I have taken the Fast Fourier Transform, FFT of the Heat Pump Power
The FFT shows Power in each sine wave component , as a function of Frequency......
With the FFT ,"Short cycling" is shown in the peak at 150 Hz with the First Harmonic shown in the second peak at 300 Hz . The Succession of Peaks at regular intervals confirms the Square wave nature of " Short Cycling".
This restrains and contains my anger with the performance of this Heat Pump , now ( March 2024) only heating one room , and that with the aid of a 1.5 kW Electric fire!!
I have, needless to say , no hot water!
ian
I am far from surprised that your heat pump is short cycling when being used to heat just one room, particularly if you also have a 1.5kW electric heater operating. Not the most efficient use of electrical energy.
I would respectfully suggest that you go back to a gas or oil fired heating system, which you may hopefully know how to operate correctly.
Sorry to do another Viktor Meldrew impersonation , but, to cool myself down I have been devising other tests for my "Short cycling "problem.
My Heat demonstrates remarkable "Short Cycling2 shown in the terrifying graph of Heat Pump power, Kw....
-- Attachment is not available --
In trying to measure , and quantify the extent of "Short Cycling" I have taken the Fast Fourier Transform, FFT of the Heat Pump Power
-- Attachment is not available --
The FFT shows Power in each sine wave component , as a function of Frequency......
With the FFT ,"Short cycling" is shown in the peak at 150 Hz with the First Harmonic shown in the second peak at 300 Hz . The Succession of Peaks at regular intervals confirms the Square wave nature of " Short Cycling".
This restrains and contains my anger with the performance of this Heat Pump , now ( March 2024) only heating one room , and that with the aid of a 1.5 kW Electric fire!!
I have, needless to say , no hot water!
ian
I am far from surprised that your heat pump is short cycling when being used to heat just one room, particularly if you also have a 1.5kW electric heater operating. Not the most efficient use of electrical energy.
I would respectfully suggest that you go back to a gas or oil fired heating system, which you may hopefully know how to operate correctly.
I suspect that even a typical (ie well oversized) gas boiler might struggle to cope efficiently with this, it would most likely be short cycling appallingly with the vast majority of the heat disappearing up the flue. There is a reason central heating is so called.
4kW peak of solar PV since 2011; EV and a 1930s house which has been partially renovated to improve its efficiency. 7kW Vaillant heat pump.
I received three different Quotes for the installation of a Heat Pump .
All three quotes selected a Heat pump on the basis of a house energy survey.
The Power required was specified at between 6.5 Kw and 8.3 Kw.
The installed Samsung Heat Pump
My Selected "installer" , originally quoting for a 6.5 Kw "Warm-flow" heat Pump actually installed a 5 Kw Samsung Heat Pump.
My Samsung Heat Pump
My Samsung Heat Pump has a Digital inverter with a power of 5kw.
Short Cycling
The Minimum power that my Heat Pump inverter can supply is 2.5 kw.
When asked to supply less than2.5 Kw the Heat pump controls the power by varying the width of a power pulse within a cycle.
Operating below the 2.5 Kw threshold is "Short Cycling".
Short cycling is caused by the reduced demand for power when the Water Temperature exceeds the Set Temperature of the Water Law Thermostat.
The Short cycling period is determined by the Volume of water in the pipes with the addition of a Buffer tank.
Need for additional, back up , heat source in winter
The notional power of the Samsung Heat Pump drops from 5Kw to 4.3 Kw ( Samsung's French estimate ) when the outside temperature drops below +3 C.
The Samsung output COP drops below to 2.8 when the outdoor temperature drops below +3 C.
Because of a 24% loss of energy across the pipes and tank the available winter power drops to 3.2 Kw.
The REAL COP , that derived from the ratio of the Energy Available to my house divided by the Energy consumed drops to 2.0.
The 3.2 kw supplied at the start of the pipe Radiator Water circuit is reduced by an unknown amount, I estimate a loss of circa 20%, giving the available power available circa 2.5 Kw.
Now , 2.5 Kw is perilously close to the Power required to heat my living room, see below , 1.9 Kw.
As with many others , I will , sometimes, need a backup source of heat during winter.
The Power consumption of my Living Room.
As you know I have measured the Actual losses within my Living room. (Note , not the U values taken from a book.)
My measured Thermal conductance for my Living room is circa 78 W per degree C.
Given that I need a indoor temperature of circa 21 C when the outdoor temperature is -3 C , the Temperature Difference is 24 C .
Therefore, the power required to heat my Living Room is 78 X 24 = 1.9 Kw.
The Electricity Bill
In December 2021 my Gas Boiler consumed some 1063 Kwh of Energy.
In December 2022 my Samsung Heat Pump consumed circa 662 Kwh.
Appreciating and allowing for all the annual differences the REAL Cop ~~ 1063/662 = 1.6 .
In December 2021 my Gas Boiler consumed some 1063 Kwh of Energy.
In December 2023 my Samsung Heat Pump consumed circa 626 Kwh.
Appreciating and allowing for all the annual differences the REAL Cop ~~ 1063/626 = 1.7
My Measured REAL COP , on the basis of my measurements is ~~ 2.0 .
Gas Supply
My Gas Boiler and Gas supply was stripped out at a cost, to me of £922.80.
I cannot return to gas.
This post was modified 12 months ago 2 times by Mars
Thanks, thats really helpful. Please forgive me if I don’t remember everything you have previously posted, whilst I ask some questions in the hope that I can be of help
"The Power required was specified at between 6.5 Kw and 8.3 Kw."
(comment) This is actually a pretty close set of estimates = good
> What was the design Outside Air Temperature?
> Do you have any corroborating evidence eg annual gas/oil consumption/smart meter readings?
My Samsung Heat Pump has a Digital inverter with a power of 5kw.
>Which model is it precisely?
>Please post a system diagram?
If you can answer these questions it should be possible to give some advice. Whether you choose to follow it is up to you!
I had my heat pump fitted July 2023 by a local heating engineer who has been specialising in renewables for possibly a decade.
My installation was an add on to my existing oil fired system with 15mm piping 7x old 1970's / 80's single panel radiators, 1x large double 1970 panel rad and a couple of modern towel rails, to create a bivalent arrangement (oil boiler is less than 5 years old and not ready for the scrap). We had one new radiator installed in the kitchen as part of the work but that was due to a recent kitchen refurb and my Wifes desire to have a nicer looking rad to suit the kitchen fittings.
My engineer came around and did a full heat loss survey, calculating every room to come up with a suitable total value of 10Kwh @ OAT -2C. I could confirm this was in the right ball park as I use roughly 1 litre oil per hour (via oil meter) when its sub zero outside.
He also listened to my desires of putting a high temperature heat pump in and recommended the Samsung 12Kw Quiet model.
All work was planned regards heat pump position, piping etc and he gave me a list of the items of work I needed to get carried out before he could start, e.g concrete plinth and suitable power supplies to the installation site.
The pump and radiator was fitted in two days and I was given a reasonably detailed presentation of the controls and technology.
I rated my fitting "very pleased" because the oudoor unit kept tripping requiring an investigation. However the reason for the electrical tripping was not actually down to my heating engineer but the electrician who installed the 32A line. This should have had its own MCB not be sharing with any other circuitry. Once corrected I have had no more issues.
My experience with the pump has been excellent and not once over the winter have my Wife and I felt cold (except in the early days when setting the heat curve), the house has managed to reach its set temp of 21 C with a fallback of 18.5C at night. The pump operates with a flow temp of between 35C and 46C most of the time.
Once I was happy with the system set up I reintroduced the oil boiler back in. This now operates with an OAT 5C or less purely from a running cost point of view. Over time this temperature threshold can be adjusted depending on oil and electricity prices with the hope I can one day switch the oil boiler off permanently!
I was a little concerned retrofitting a heat pump to old radiators but my engineer had little concern because of the way sizing calculations were done in the those days i.e adding 50% was common practise which actually worked in my favour.
I have since expanded my knowledge even further from this forum, HeatGeeks videos and trawling the web. The only downside for knowing more about the subject is it has exposed to me how oversized my oil boiler is for my property (fitted by another company 5 years ago). It is 26 Kw, 2.5 times bigger than it needs to be!! It is now set to its absolute minimum of 65C and still heats the house to 21C at an OAT of -5C.
After reading some of the painful stories written by a few unlucky people, I feel very blessed and fortunate that I have such a skilled company on my doorstep. I have realised the quality of the planning, design and fitting of these systems is absolute key to a good customer experience. I also believe this is the main reason for the very obvious reluctance of people to adopt the technology in the UK due the high levels of bad press surrounding peoples bad experiences of cold houses and high running costs after installing a heat pump from a poorly trained heating company.
5 Bedroom House in Cambridgeshire, double glazing, 300mm loft insulation and cavity wall insulation
Design temperature 21C @ OAT -2C = 10.2Kw heat loss
Bivalent system containing:
12Kw Samsung High Temperature Quiet (Gen 6) heat pump
26Kw Grant Blue Flame Oil Boiler
All controlled with Honeywell Home smart thermostat
@technogeek congrats on the high quality install. It’s great to read success stories. Is the installer a sole trader or a company. Would be worth recommending him.
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