Posted by: @bontwoody

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@alfapat 

So this is the lockshield valve

Sometimes they have knurled knobs on which can be used to adjust them, but if not then just use a small adjustable spanner.

You can use the thermometer probes to balence the radiators if you want to. There should be a 5-7C drop from the incoming tail to the outgoing one. I just adjust untill the room temperature feels right.

The buffer issue and the radiators balencing are seprate issues which will both aid your efficiency. The better you can get the efficiency the lower your bills will be. getting rid of your buffer will likely improve your efficiency by 8%ish. Lowering your flow temperature by 5C maybe another 10%ish. Replacing the antifreeze solution with water and anti frost valves another 5%ish. It all adds up.

The issue with removing the buffer tank is making sure that the flow rate is still high enough for the heat pump to function correctly, this is down to the size of the pipes in your heating system and the water pump/s.

Homely takes over the running of your heat pump, but Im not sure how much information it provides, perhaps @toodles  can  help?

Its a lot to take in I know but keep on with the radiator adjustment 🙂

So, I am now three quarters through the radiators using temp probes , I have stopped this morning as the system is not circulating due to warmer temps outside . All the rads have been screwed down at the lockshields and then opened 1.5 turns . I guess its a case of whether I need to screw any of the bedroom temps down as I usually keep them down a bit. My conservatory rads are only on a quarter turn open , was on frost with TRV,  so I will see if that is too much or too little.

So far most the Rads vary from inlet to outlet with a difference of 4c, 0.3, 8c(small rad ), 2.2, 1c. 2c, 7.5c, 2.5c.

The mean averages of ones I have done are 27c to 32 and 22 to 25c , this may not be relevant .

Do I go back to flows at the tank and see  all four pipes flows are doing there, or does not tell me anything. The pump flow temperature has been sitting at 46c during all this. What do I monitor now once I have finished all rads , is that it and see if OAT keeps the system more economically.

PS. £10 less in daily usage between the last two days , but the OAT is a lot higher.

@alfapat If you have now reached a point where all your radiators are providing appropriate levels of heat in the room compared with all the others, (if you haven’t reached this point, then your radiators are not yet balanced) then you should now be able to determine if your heat pump is providing the right amount of heat to equate with the house’s heat loss.

The balancing process evens out the distribution of the available heat but the output from your pump determines your comfort level. If you are too warm (the TRV’s should still be fully open by the way), then it is time to reduce the output from the heat pump. If you are not warm enough, then the heat pump needs to provide more heat. In both cases, the usual means of control is to adjust the flow temperature from the heat pump.

By the way, have you balanced the system with one of the LSV’s still fully open? [This will be the radiator that warmed up more slowly than all the others] This provides for the lowest resistance for the water pump to provide the flow at the lowest flow rate which usually equates to least noise from the system and lowest pump energy consumption. (Our Wilo Pico pump runs at a rate of ~ 8-9 watts; my Daikin Service engineer remarked on how low a resistance our system has!) Regards, Toodles.

@alfapat the flow temperatures in and out of the buffer tank aren’t really something you can do anything about. They just indicate how much efficiency you are losing by using a buffer tank. 

with your radiators balanced it is just about finding the correct water law settings for your own comfort levels. 

@toodles By the way, have you balanced the system with one of the LSV’s still fully open? [This will be the radiator that warmed up more slowly than all the others] This provides for the lowest resistance for the water pump to provide the flow at the lowest flow rate which usually equates to least noise from the system and lowest pump energy consumption.

The radiator used that is fully open , is the same one that the original installer left in there set up . Pipe wise I can only assume that its on the return line ?

What I cant understand is because its mild just now , I will have to see if the temperatures reach the same when cold outside, and then see if 46c copes with that setup. Yeah?

@alfapat The radiator that has a fully open LSV is likely to be at the ‘far end’ of the pipe run, it should still be fed from the flow and should ‘drain back’ so to speak via the return - this is normal practice. What you might care to do is open the next slowest to heat up a little more and so on to reduce the resistance on the flow even more. The aim will be that you might be able to further lower your heat pump’s LWT.

If you are using WC as suggested, this will take care of the varying Outside Air Temperature (OAT) so that you should not need to make constant adjustments to the flow temperature as the weather varies the OAT.

It is a balance that takes some time to finesse but once you have the WC set with the curve looking after the swings in temperature, the whole system should look after itself most if not all the time for you.

I stressed adjusting the LSV’s because with them set and well balanced, you should have comfort levels in all rooms and be able to achieve this with the most economical flow temperature from the heat pump. In time, if you find a room is just too warm or cool, you now have reached the point where you finesse the tweaking on that LSV. It may take time - but it is worth the effort. Adjustments are best carried out in small increments and left for say 12 hours or more to see what effect they have on the system and comfort levels. Best of luck and Happy Tweaking! Regards, Toodles.

@toodles What I don’t know what would be the next slowest , however , I will now check all that have 1.5 turns , then adjust room temps , some of them a bit high , wel three bedrooms anyway. Then drop the flow temp 2 degrees from 46 c , see how that pans while the present temps stay as they are.

@alfapat Everything as commented above is pretty much spot on- the lower the flow temperature the heat pump is being asked to produce, the better the efficiency is and the lower the electrical consumption is.

There will be a 'sweet spot' for WL which is ideally calculated by the installers at design so they know what the required flow temp is at outdoor design temp, eg 45 deg max flow temp at -2 outdoors and so forth. No higher than 45 ideally. Just adjust the WL (or max/min flow temp) by a degree or so every few days and see if the house still remains at a comfortable temperature for you. That's the real test rather than actual flow temps being produced, although the two are connected, it's better to focus on comfort levels rather than a percieved low flow temp. That is, as long as your radiators/UFH is sized appropriately.

If it's a renovation project with good insulation and UFH 45 deg max temp should be more than sufficient and I hazard you could even go lower than that as long as you are using WL to drive the system and don't have a seperate room thermostat setup.

Let us know how you get on.

@alfapat The WC (once set to your satisfaction) will take care of most variations in the OAT, so once you have a workable balance between all the radiators, then you will be able to determine whether you need to raise the LWT to achieve your comfort level. There’s theory and practice and this is where the finessing of the LSV’s comes in - as I have mentioned before, this is what retirement (and patiencs) is all about.😉 Regards and Happy Tweaking! Toodles.

Posted by: @rob_cirrus_energy

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@alfapat Everything as commented above is pretty much spot on- the lower the flow temperature the heat pump is being asked to produce, the better the efficiency is and the lower the electrical consumption is.

There will be a 'sweet spot' for WL which is ideally calculated by the installers at design so they know what the required flow temp is at outdoor design temp, eg 45 deg max flow temp at -2 outdoors and so forth. No higher than 45 ideally. Just adjust the WL (or max/min flow temp) by a degree or so every few days and see if the house still remains at a comfortable temperature for you. That's the real test rather than actual flow temps being produced, although the two are connected, it's better to focus on comfort levels rather than a percieved low flow temp. That is, as long as your radiators/UFH is sized appropriately.

If it's a renovation project with good insulation and UFH 45 deg max temp should be more than sufficient and I hazard you could even go lower than that as long as you are using WL to drive the system and don't have a seperate room thermostat setup.

 

Let us know how you get on.

Thanks for that Rob. On the Samsung Gen 5 set up it says -5c for Scotland , it's not often that cold , but having said that it was last week. However its set on that and has been since installation. The other WL setting has been 50c since installation , but since tackling this balance and learning more about it I have had it at 46c , I am hoping to reduce this once I sort room temps. What I don't know is how this will adjust or compensate and when it gets colder.

The installers/designer went bust 6mths after installation, So its been an expensive 8 years trying to sort all this myself!

Are you saying that the Battery powered Danfoss TP5000Si thermostat (it can be moved room to room ) becomes redundant after this or is it still a part of the set up. It often fails to communicate wirelessly and keep stable temps which throws a spanner in the works, I'll maybe think about Homely yet.