@jamespa

My original suggestion for the WC settings was a LWT of 25C at an OAT of 20C, the reasoning behind this is that it should not require much if any adjustment. Obviously Ian set it at 25C at 15C, so adjustment as James suggest may be necessary.

To make any real progress we actual need measurement and display of IAT and OAT. Have you made any progress in supplying this data Ian?

Fair enough and I think that means we don't disagree materially.  I believe 15C is Samsung's default 'low end'. 

I'm sure you would also agree that Ians approach of adjusting the water law offset is also a valid way of determining the correct value (which can then be programmed in) provided he takes notes and doesn't fiddle with the water law offset more frequently than say once every 12 hours.

I also agree we need, from Ian, some data on OAT and IAT however obtained.  If we had a location OAT is available on the internet.  IAT obviously isnt!

@derek-m further to the above discussion and particularly in view of the desired room temperature of 23 not 20, I would agree with you that changing the high end from 25:15 to 25:20 is a good tweak.  Apologies that I missed that this was your original suggestion (there is a lot going on!).

Until this has been done and the effect assessed I would personally leave the low end where it is.

@jamespa & @deerek-m

Results from evening of 13th Sept 24.

Legionnaire Warning

Despite not using the Hot Water , because of the expenses, I still perform the legionnaire water sterilisation every Friday for one hour.

The legionnaire sterilisation changes the water temperatures, COP and REAL COP ( the COP as measured at the start of the Radiator secondary water circuit.

Results:

1) Pipe Water Temperatures , taken with a Sharky Power meter at the start of the Radiator circuit .

I increased the Water Law offset from 0 C to +3 C successfully increasing the room Temperatures from 21 C to 23.5 C .

2) Pipe Delta_T Temperatures, , taken with a Sharky Power meter at the start of the Radiator circuit .

Delta_T varied between 3 C and 4 C, even when the Water Law offset was used.

The Reduction in Cycle time is clearly shown as a function of Water Law Offset.

3) Power carried by water in radiator water circuit:,, taken with a Sharky Power meter at the start of the Radiator circuit .

 Power carried by the Radiator water is  perfectly constant, showing only system noise.

4) Electrical Power , taken with a CT transformer attached to the total electrical input to the Heat Pump including all motors and controls.

Power taken against Absolute Calendar time.

 Note the large power spike taken during legionnaire sterilisation.

5) Electrical Power as a function of Relative time in Seconds 

The first showing legionnaire sterilisation , the second showing the increasing power taken by increasing the Water Law offset , while the third shows the power used during the morning of the 14th Sept 24.

6) COP and REAL COP

Both the COP and REAL COP have fallen .

7) Losses

The system loss has increased.

8) Energy Consumption

The Energy consumed has increased.

9) Cycling and Run Time

The Average cycle and Run Times have remained constant.

Conclusions:

1) The COP and REAL COP have reduced .

2) The Energy Loss has increased even allowing for the increased legionnaire consumption.

3) The Room Temperature control is indirect , using the Water Temperature / Water Law offset .

4) My "Off Peak , Octopus "Cosy" tariff could not be used due to the absence of direct Water Temperature  or Energy controls.

5) The Average Cycle and Run times have remained constant.

I will build another two sensors to measure and record the outdoor and indoor temperatures  .......

@iantelescope 

Ian,

Obviously with the heat pump operating, could you please read the various values from the Sharky display and post them. It should be possible to read the flow and return temperatures along with the flow rate and power.

It would appear that the Sharky is not providing accurate data.

Thanks for the data: some questions

Posted by: @iantelescope

↑

1) The COP and REAL COP have reduced .

you say these measurements are affected by the DHW sterilisation.  Please can you advise how you calculate COP and real COP, what are you comparing?

Since your total electricity consumption peaks just above 200W (except during the legionnaire cycle) and has a quiescent value of just over 100W then, at the current rather mild temperature, you are basically putting 100W into heating and 100W into pumps etc.  If you are getting 400W delivered to the emitters then the thermal COP is actually 4.  The 100W into pumps etc wont change much as the temperature cools so it will become much less dominant.

That said both Derek and I are suspicious about your measurement of power delivered to the radiators, its far too constant and apparently (so far as I can tell) didn't increase when you turned up the flow temperature, which is not consistent.  Are you certain its correctly configured?

Posted by: @iantelescope

↑

2) The Energy Loss has increased even allowing for the increased legionnaire consumption.

 

What do you mean by energy loss?

Posted by: @iantelescope

↑

3) The Room Temperature control is indirect , using the Water Temperature / Water Law offset .

Correct, thats how it is and how it should be.  The idea is to get the water law parameters correct and you will then get a stable house temperature without constant tweaking.  You need to bear with the plan for some time to get there.

Posted by: @iantelescope

↑

4) My "Off Peak , Octopus "Cosy" tariff could not be used due to the absence of direct Water Temperature  or Energy controls.

This is the first time you have mentioned the cosy tarrif to the best of my recollection.  If you want to automate the response to this you will almost certainly need to consider homely, however you will get variations in house temperature as a result. Unfortunately the maths to optimise the use of ToU tariffs isn't simple and you really need to take into account forecasted temperatures.  Thats Homely's USP (Im not trying to sell it, just stating my understanding)

Until your system is operating stably then I wouldn't even think about tariff optimisation.  Currently you are hardly heating at all, and hardly burning any energy, because the OAT is mild so there is time to think about this once the system is stable.

Posted by: @iantelescope

↑

5) The Average Cycle and Run times have remained constant.

Noted.  At the current mild outdoor temperature cycling is ineviatble whatever you do, dont worry about it!

I think it may be time to tweak the warm end of your water law from 25:15 to say 25:20.  The latter was Dereks original suggestion and as you want a room temperature of 23 it makes more sense to push the warm point out.  This will also push up the flow temperature at the current OAT (so you can reduce the offset) whilst ensuring the system doesnt put in too much energy when its above 15.

@derek-m  &  @jamespa

Additional observations on the Heat Pump performance and adjustment on the evening of the 13th Sept 24.

1) Adjusting the Water Law definition coordinates [+15:25] and {-5:45]

The Samsung Heat Pump controller has a security entry code system entered by pressing the + and - buttons followed by a variable time delay.

Continually changing any setting can become explosively irritating resulting in ***** expressions!

The use of the Water Law offset to Offset the entire Water Law:

is much to be preferred!

2) I will build further sensors for both room and outside .

3) Last nights outside Temperatures started at 14.7 C falling to 13.1 by midnight and remaining at 13 C throughout the night.

Posted by: @iantelescope

↑

@derek-m  &  @jamespa

Additional observations on the Heat Pump performance and adjustment on the evening of the 13th Sept 24.

 

1) Adjusting the Water Law definition coordinates [+15:25] and {-5:45]

The Samsung Heat Pump controller has a security entry code system entered by pressing the + and - buttons followed by a variable time delay.

Continually changing any setting can become explosively irritating resulting in ***** expressions!

The use of the Water Law offset to Offset the entire Water Law:

-- Attachment is not available --

is much to be preferred!

2) I will build further sensors for both room and outside .

3) Last nights outside Temperatures started at 14.7 C falling to 13.1 by midnight and remaining at 13 C throughout the night.

 

 

 

 

 

Constantly changing any setting is indeed annoying ,and shouldn't be necessary once its set up correctly.  However you need to put in a bit of effort up front to set it up correctly, otherwise you will forever have a manually operated system.  If that's what you want then so be it, but its not a great idea and, unless you proactively change the settings based on OAT not IAT, will forever lag.  Worse still, when we get to the season where its fairly warm daytime and cold at night, you will wake up cold unless you get up in the night to tweak the offset proactively.  

Thanks for the OAT info, basically its a stable 13-14C, ideal conditions for setting up the warm end of the WC curve so now is the time to do it!

• Sorry but you really do need to tweak your water law settings for now, its part of the process of setting up a heat pump.  Please do this and be prepared to do it several times more, but not indefinitely.
• Please can you tell us what the temperature difference is flow to flow across the heat exchanger (sens3 to sens 7 I believe)
• Pleas can you also respond to the query by @derek-m with which I wholeheratedly agree:

Posted by: @derek-m

↑

Obviously with the heat pump operating, could you please read the various values from the Sharky display and post them. It should be possible to read the flow and return temperatures along with the flow rate and power.

It would appear that the Sharky is not providing accurate data.

@jamespa 

Power and Energy measurements

The Power measured by my sharky Water Power meter was on the 10th sept:

The Power shown at the start has a constant amplitude of 400 W. 

However, the average power across the cycle is :

Ave Cycle Power = Power_Amplitude X Run_time ( in seconds) / Cycle_Time ( in seconds )

As I pointed out, earlier , it is perfectly possible to produce an apparent power in mega Watts!

 Chernobyl! ?

@iantelescope our posts crossed, so to reiterate the key points:

Constantly changing any setting is indeed annoying ,and shouldn't be necessary once its set up correctly.  However you need to put in a bit of effort up front to set it up correctly, otherwise you will forever have a manually operated system.  If that's what you want then so be it, but its not a great idea and, unless you proactively change the settings based on OAT not IAT, will forever lag.  Worse still, when we get to the season where its fairly warm daytime and cold at night, you will wake up cold unless you get up in the night to tweak the offset proactively.  

Thanks for the OAT info, basically its a stable 13-14C, ideal conditions for setting up the warm end of the WC curve so now is the time to do it!

• Sorry but you really do need to tweak your water law settings for now, its part of the process of setting up a heat pump.  Please do this (from 25:15 to say 25:20.) and be prepared to do it several times more, but not indefinitely.
• Please can you tell us what the temperature difference is flow to flow across the heat exchanger (sens3 to sens 7 I believe)
• Please can you also respond to the query by @derek-m with which I wholeheratedly agree:

Posted by: @derek-m

↑

Obviously with the heat pump operating, could you please read the various values from the Sharky display and post them. It should be possible to read the flow and return temperatures along with the flow rate and power.

It would appear that the Sharky is not providing accurate data.

 

• Finally please can you get explain what you mean by 'energy loss' above?

@jamespa 

COP and REAL COP:

COP ?

My Measurement of the Heat Pump COP is:

COP = Energy Generated as displayed on the Samsung front panel under Energy Generated( kWh ) / Energy consumed as displayed on the Samsung front panel under Energy consumed ( kWh )

REAL COP ?

My Measurement of the REAL COP is:

REAL COP = Energy as displayed on the Sharky front panel today ( kWh ) - Energy Generated as displayed on the Sharky front panel yesterday( kWh )

/ Daily Energy consumed as displayed on the Samsung front panel under Energy consumed ( kWh )

Loss ?

My Measurement of Loss is:

Loss %  = ( 1 - Energy as displayed on the Sharky front panel today ( kWh ) - Energy Generated as displayed on the Sharky front panel yesterday( kWh )/ Energy Generated as displayed on the Samsung front panel under Energy Generated( kWh )  X 100 .

@iantelescope

Could you please provide a graph of the data from sensor 1 covering the past 24 hour period?