Posted by: @alfapat

↑

Thanks James , just trying to get assurance thats all ,and trying my best within my capabilities.

I will stay static for a whille now.

Cheers!

Understood.  Unfortunately, because we can't control the environment, we all pretty much have to trust the specs and the physics.  Fortunately all heat pumps have similar characteristics because they all depend on the same physics.  

I have personally found that operating on weather compensation alone gives me a much better level of comfort than I ever had with my previous gas boiler and complicated controls, and I look to be on track to save perhaps 10% in operating cost.  So far as I can tell, the physics is working for me as it should.  Of course that's just me and my system.

Hi @alfapat

I hope you are getting close to optimising your system.  

There is a discussion on this thread https://renewableheatinghub.co.uk/forums/thermostats-trvs-pumps-valves/how-to-balance-radiators-the-role-of-the-lockshield-valve/paged/4#post-40825  about how to use a Samsung controller to effect a setback.  Also some information about times setbacks using the Samsung controller alone, which is almost certainly the best way to do it if yours has the capability (it may be available only on more recent controllers, but perhaps firmware upgrade is a possibility)

@jamespa Thanks for your interest again . I thought I was , were I was down to 41c flow but ultimately although the temp in more consistant the energy needed doesnt seem to drop . Currently I have reverted to 44c where I got better results.

Quite interested in your link but it takes me back to the same page we are on, Ill look again 

Incedently I am trying to find out if Homely is compatible with my 8 yr old pump but no answers yet

Here is the corrected url to the other thread https://renewableheatinghub.co.uk/forums/postid/41097

Without vastly more information about your system and the measurements that I care to ask (and likely than you care to give) I wont attempt to speculate on the explanation for your energy measurements, but the most important thing is that you are happy and warm.

I will have a look , thank you . 
Hey , warm , but not happy yet, don’t worry , keep the thoughts ongoing! 😏 

Yeah , interesting , looks like Honely is the nearest to solving my system, if it’s compatible with Gen 5 . 

Homely gets good reviews on this forum.  The Samsung controller historically is a bit lacking in features (maybe the later ones are better) and homely fills the gap, albeit for some of its more advanced features requires a subscription.  You have to fit the modbus interface to the Samsung I believe as well.

Help required here , I have had two calls from Homely and I still cannot find out whether Mod Bus is compatible with Gen 5 Samsung Heat pump. 

Your Link to Grahams Heat pump Weather compensation video mentioned a Hand over book /manual for Samsung Gen5 . It seems impossible to find on Samsung's site. Can anyone help.

Something not right yet , In the middlle days of Jan the average temperatures were 6c and 4c they are not that different now . In my quest to get the flow temp down I have been down from 45c to 41c . It did look like that the system struggled to keep things the same at that.

Seeing that I had smaller usage of energy , up to half that ofthe last  4 days I put the flow back up to 44c . Figures I am looking at are in the middle of January between 40 and 60 kwh and last 4 days 70kwh plus . 

Something not right.

Posted by: @alfapat

↑

Something not right yet , In the middlle days of Jan the average temperatures were 6c and 4c they are not that different now . In my quest to get the flow temp down I have been down from 45c to 41c . It did look like that the system struggled to keep things the same at that.

Seeing that I had smaller usage of energy , up to half that ofthe last  4 days I put the flow back up to 44c . Figures I am looking at are in the middle of January between 40 and 60 kwh and last 4 days 70kwh plus . 

Something not right.

By 'flow' I presume you mean FSV parameter 2021.  I am assuming you have left 2011 constant (at what value)

As I mentioned earlier, consumption over anything less than several days is pretty meaningless because the house has a memory of 24-48 hours (sometimes more), and consumption over several days is also meaningless because the conditions vary too much.  Pretty much the only way to compare consumption is by plotting vs OAT over several weeks or more. 

As I recall you put the FT back up because the consumption had gone up when you put it down, now you are finding that it goes up when you put it up!  I fear the problem is that you are looking at the scatter on the figures rather than anything particularly meaningful.  Obviously I cant be certain about this because there are features of your system, most notably the buffer, which might behave in an unexpected way, but in the absence of anything odd scatter on the figures is the most likely explanation.

Genuinely the only way I know to do this is to trust the science.  Open up all the TRVs, set the thermostat as high as it will go so its constantly calling for heat, set 2012/2022 to a suitable pair of values for the warm end then adjust 2021 down until the house just keeps warm.  Monitor over several weeks and tweak slightly up/down as necessary to get the right value.  Check the daily but more importantly weekly COP to see if its sensible and address any obvious problems if any.  If you are happy with the consumption enjoy!  

If you arent prepared to trust the science I think your optimisation process is going to need at least a season, possibly two, so you can do a meaningful plot over a period of weeks for each change.  

To give you and idea Here is a scatter diagram for my system over a period of 3 weeks in January.  Its plotted vs degree-days, a slightly modified average OAT.  Changing FT by 3C will result in 6-10% change in efficiency.  The scatter, particularly in the interesting region where most of the points are, is probably double that indicating that more data would be needed to dig out of the noise the effect of changing the FT.  No changes to the system were made during the period over which this data was collected.

Sorry I don’t understand the graph, and I don’t know how work out COP. 
What I can tell you are my Settings  2011 is -5c for Scotland

2012 is 15c ambient temp for wc

2021 is 44c Flow temp

2022 is 32c Flow temp in mild weather 

2091 set at No 1 for run signal at terminal B22 

Trv’s all open and lock shields appropriately set . 

House definitely warm sitting around 21-22c

Attached is pipe arrangement on Heating tank

Sorry for not explaining the graph.  Each point represents one day.  The horizontal axis is the degree-days figure for the day (degree-days is a slightly modified average outdoor temperature, easily downloaded from the internet for a weather station near you).  The vertical axis is power (in Wh) consumed during the day (24hrs).  As you can see the power varies a lot from day to day even for the same number of degree days (average OAT).  This variation will swamp any change due to flow temperature changes until you have more data.  

The plumbing of your buffer tank is correct however a 10C drop is a lot, and makes me wonder if there is mixing going on in it.  Not much you can do really, buffer tanks are a pain which are rarely actually needed, but all to frequently installed particularly 8 years ago.

COP is energy supplied to house /energy supplied to heat pump, should be in the region of 3-4 most days.  Its basically a measure of the 'free energy' you get with a heat pump which is what makes them so efficient.  I dont know if the Samsung controller tells you the figures (manual is unclear), some do some don't, if it does it would be under 'information' or 'energy'.  If it doesnt tell you the figures you cant calculate it unless you measure the power externally, so you may be out of luck here.

Your FSVs are reasonable, you may want to drop 2022 a bit if you are too warm when it gets milder, otherwise concentrate on getting  2021 to the point where the house is the right temperature, which you appear to be close to.