@iantelescope

I fail to understand what on Earth you are talking about, a run time of 10 milliseconds?

Have you carried out the actions that I suggested?

Posted by: @iantelescope

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@derek-m

You are correct , the major problem I face is replacing the Thermostat .

"Homely" recommend their Thermostat for my Samsung with my Samsung being  already fitted with TWO Water circuits. The very same Water circuits, Motors and Buffer tank that  many recommend that I remove!!

I have, from the start asked for the removal of the Heat Exchanger .................receiving condescension from both Samsung-Dallium , Samsung-France and my "installer". It will never happen".

Please do not attack me , the customer,  I am an past  expert at self denigration !

 

It is clear (and has been all along) that the advice you are receiving from tradesmen is inconsistent with the advice you are consistently receiving from the members of this forum.   

Unfortunately you continue to listen to the tradesmen, whose principal motivation is (inevitably) to sell you things, rather than to those on this forum, whose only motivation is to help.

Whilst you continue to listen to tradesmen, with their vested interests, you will continue paying money, but will almost certainly not fix the problem, not least because you appear to be totally unable to distinguish between tradesmen giving potentially good advice and tradesmen who are giving poor advice.

There is absolutely no point in you posting here, or in anyone responding, if you are going to trust the tradesmen rather than those here.

If you genuinely want help you need to do what Derek says and report back, nothing more, nothing less.  We don't need or want to hear about random measurements you are making, we need to hear the results of the experiment.

If you are unwilling or unable to do this please just say so.  If you don't want help please stop posting and thereby wasting the time of others.

Finally this is not an attack, just fact.  Sometimes fact is inconvenient.

@derek-m 

ok derek, I have shorted the Thermostat out and changed the Weather compensation curve to coordinates [+15:+25] and [-5:+45]

With the retained heat it will take some hours to cool down .........I will report tomorrow.

Just hope it is not cold tonight!

Posted by: @iantelescope

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@derek-m 

ok derek, I have shorted the Thermostat out and changed the Weather compensation curve to coordinates [+15:+25] and [-5:+45]

With the retained heat it will take some hours to cool down .........I will report tomorrow.

Just hope it is not cold tonight!

 

@iantelescope 

Good.

Why are you expecting the house to cool significantly?  If I understand your system correctly your secondary (radiator) pump should now be running continuously and your heat pump should more or less make up the house loss, with its FT determined by the EC curve.  Is something different happening?

@jamespa & @derek-m & @editor

Thermostat shorting:

I have shorted my Thermostat output at 1500 on 11th of Sept 24.

I have altered the Water Law coordinates to [+15:25} and [-5:45]

The Results:

1) Radiator Water Temperatures

Pipe Water Temperatures on the Radiator Circuit taken with a Sharky Water Meter inserted into the water flow.

All results taken before 1500 on the 11th Sept act as a Reference to the reading after 1500 on 11th Sept.

This is the water Temperature on the Outgoing Radiator Water pipe.

This is the water Temperature on the Return Radiator Water pipe.

This is the Delta_T between the outgoing and Return Radiator water pipes.

2) Run and Cycle Times:

This is the power taken from 1500 on 11th Sept until 0700 on 12th Sept.

This is the Reference Cycle and Run Time , 20/6 minutes, before 1500 on the 11th Sept.

These graphs show the Cycle time reducing through the night, with the average Cycle time being 8.6 minutes with a Run time of 4.14 minutes.

The graph on the extreme right shows a close up of the cycling with a Cycle Time of 8.3 minutes an a Run Time of 4.3 minutes.

The outdoor Temperatures started at ~14.1 C at 1500 on the 11th falling to 11.3 at 0700 on the 12th Sept.

3) Heat Exchanger Temperatures:

This shows the Input pipe Temperatures on the Heat Exchanger taken with DS 18B20.

This shows the Output pipe Temperatures on the Heat Exchanger taken with DS 18B20.

This shows the Delta_T , Input pipe minus output Temperatures on the Heat Exchanger taken with a pair of DS 18B20.

4) Heat Pump output Temperatures:

This shows the Heat Pump Output pipe Temperatures on the input to the Water Tank  taken with a K type Thermocouple.

Room Temperatures

The indoor Living room  Temperatures fell to 17 C at 1600 on the 11th Sept climbing to a ~~ 22.4 C at 0700 on the 12th Sept.

After 15 hours the Room Temperatures have not stabilized , climbing asymptotically to about ~23 C.

Room Temperatures cannot be controlled with the Thermostat Shorted out.

Conclusions :

1) The Water Law,Weather Compensation controls do function without a Thermostat. The room Temperatures are stable and controlled well within reasonable limits.

2) The user has no control over the room Temperature, only an indirect control using the Water Temperatures using the Water Law offset screen.

3) The Rise time , the time taken by  the Heat Pump to reach a stable Temperature is about 6 hours compared to the Thermostat rise time of 6 minutes.

4) The Cycle Time , set to exactly 20 minutes using the Thermostat reduces to 8.6 minute Cycle time with the Run Time reducing to 4.14  minutes.

Many more megabytes are available if required.

Good, the graphs will take some looking at to see if there any insights.  @derek-m may beat me to it.  

If it looks like room temperature is genuinely stabilising at 23C, and given that the outdoor temperature is 11-14C then you will want to turn down the high temperature end of the WC curve a bit from +15:25 to say +15:23.  This will be an iterative process.  You will need to have the confidence to stick with it, it may take some time.

Can you please confirm that, with the external thermostat shorted, the radiator pump runs continuously (and if it doesn't, what is controlling it)?

@iantelescope

In summary this all looks good so far. 

I can offer the following initial observations on the graphs

Posted by: @iantelescope

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1) Radiator Water Temperatures

 

These are showing a small deltaT compared to the 5C benchmark which is unsurprising given the high OAT and the fact that the radiator pump is operating at a fixed speed, and therefore the radiator deltaT will be less at higher OATs.  Nothing to worry about

Posted by: @iantelescope

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2) Run and Cycle Times:

...These graphs show the Cycle time reducing through the night, with the average Cycle time being 8.6 minutes with a Run time of 4.14 minutes.

Exactly as you would expect.  As the house reaches equilibrium temperature the heat loss from radiator to house will reduce, so the heat pump will cycle more.  At the current OAT the heat pump will inevitably cycle at the equilibrium point.

Posted by: @iantelescope

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The graph on the extreme right shows a close up of the cycling with a Cycle Time of 8.3 minutes an a Run Time of 4.3 minutes.

The outdoor Temperatures started at ~14.1 C at 1500 on the 11th falling to 11.3 at 0700 on the 12th Sept.

Depending on whether you mean 8.3 off/4.3 on or 4 off/4.3 on this indicates that the minimum output of the heat pump is either about one third or one half of the demand at the OAT.  One half is fine, one third might indicate a somewhat oversized pump, but until we have more data I wouldn't worry too much.

Posted by: @iantelescope

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3) Heat Exchanger Temperatures:

...This shows the Delta_T , Input pipe minus output Temperatures on the Heat Exchanger taken with a pair of DS 18B20.

Im assuming the measurement is flow (from heat pump) compared to flow (to radiators).If this is the correct interpretation then the delta T across the heat exchanger is 2C.  This will result in an efficiency penalty of 4-6%.  Not worth worrying about for now but avoidable with replumbing.

Posted by: @iantelescope

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Room Temperatures

The indoor Living room  Temperatures fell to 17 C at 1600 on the 11th Sept climbing to a ~~ 22.4 C at 0700 on the 12th Sept.

After 15 hours the Room Temperatures have not stabilized , climbing asymptotically to about ~23 C.

Room Temperatures cannot be controlled with the Thermostat Shorted out

Based on this short experiment its performing as expected, asymptotically reaching a stable temperature.  It needs a bit more data to be certain but, assuming you want a room temperature of 20C then you can follow my suggestion above to start tweaking the WC curve namely:

"If it looks like room temperature is genuinely stabilising at 23C, and given that the outdoor temperature is 11-14C then you will want to turn down the high temperature end of the WC curve a bit from +15:25 to say +15:23.  This will be an iterative process.  You will need to have the confidence to stick with it, it may take some time."

Posted by: @iantelescope

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3) The Rise time , the time taken by  the Heat Pump to reach a stable Temperature is about 6 hours compared to the Thermostat rise time of 6 minutes.

Low and slow is most efficient, this behaviour is expected if you want to operate efficiently

Can you please confirm 

1. What is the status of the buffer tank.  Is it in circuit or did you block flow through it using a valve?

2. With the external thermostat shorted does the radiator pump run continuously (and if it doesn't, what is controlling it)?

@iantelescope

Can you show graphs detailing the heat pump flow and return temperatures, the IAT and the OAT.

Is the heat pump running continuously?

@jamespa 

Hi James,

Buffer Tank:

The Buffer was connected during the night .

Motor continuously running:

Both motors are constantly running at a constant speed with , so far no sign of excessive noise or wear.

Short Cycling?

The Thermostat , in imposing a fixed cycle Time while varying the Run Time limits the effects of "Short Cycling".

Without a fixed Cycle Time imposed by the Thermostat , the Cycle Time and Run Time are considerably reduced..

This would appear  to  be the  Reason for the continued use  of a fixed cycle Time Thermostat?.

Space Mega bytes:

The Hub objected strongly to the size of my files.

Here are some of the remainder:

1) Energy Consumption:

Notice the considerable increase in energy consumed during the night.

2) COP

The COP, and the COP as measured at the start of the Radiator circuit , have considerably reduced.

3) Run and Cycle Times

The Cycle and Run Times at both the Heat Pump output and at the start of the Radiator circuit have reduced considerably.

My Energy Supplier, Octopus has , earlier today,  produced an energy consumption for the night of ~ 8 kwh .

My Energy Supplier, Octopus has, subsequently , withdrawn the earlier estimate , without explanation ....................?

@derek-m 

Motor Wear:

Both motors are in continuous and constant use,

Heat Pump wear:

The Heat Pump itself is being subjected to a continuous ON/OFF motor demand .

The Cycle time has reduced from the Thermostat imposed 20 minutes to an average of 8.6 minutes.

The Run Time has been reduced from the 6.64 minutes on the 10th Sept to , currently , an average of 4.3 Minutes.

Heat Pump Output:

I have a quartet of Thermo couples attached to the outside of the water pipes from the Heat Pump at the end of  6 meters of 28 mm pipes.

 Here the Temperatures are shown at the point just before the primary Grundfoss Motor.

The Pipe Temperature offset is here +3 C because of the pipes , external contacts clamps and Thermo couple offset drift .

Here the Temperatures are shown at the point just after the return to he Heat Pump.

The Pipe Temperature offset is here +3 C because of the pipes , external contacts clamps and Thermo couple offset drift .

A better measurement is obtained using the DS18B20 attached to the input to the Heat Exchangers.

Here the Heat Exchanger input , output and Delta_T are shown.

The DS18B20 's are much more accurate but suffer from the same attachment problems as the Thermo couples.

I would wish for a second Sharky measuring , and checking the output from the Heat Pump itself .............

The Sharky with it's internal Water Thermostats is both much more accurate, outputting  to the European M-BUS.

@iantelescope

Can you please close the valve so that the buffer tank is no longer in use.

@iantelescope 

Thanks for the replies.

No conclusion can be drawn from the energy graph without also showing oat and it.  Suggest to ignore for now.  10kWh per day is about 500W which is in the right order at this time of year.  Much if this is probably fixed consumption so no real conclusions can be drawn.

Your cop curves show both cop and real cop increasing so far as I can see however without oat and uar no conclusions can be drawn, and anyway this is too short a period to evaluate properly.

Please shut the valve to take the buffer tank out of circuit as requested by @derek-m  

Assuming you want your house at 20C not 23 C please reduce the high end of the WC curve as I suggest above, from +15:25 to +15:23.

These are the two next steps.  You could omit changing the WC curve for now so we can see the buffer tank effect in isolation, or just do it if 23 is too hot for you (it would be for me!).