THZ / LWZ Tecalor Stiebel Eltron Heizung

[willybauss]

@immi:
something went wrong with the shutdown + restart. After another restart the value of 1.5° was correct even in the heating curve graph, and even without my factor of 0.1. But it cannot be related to an outdated version. My previous version was 0.090 which didn't have the heating curve graph at all. Maybe I opened the heating curve too early after restart, when p14 had not yet been read by 0.094, so the wrong old value of 0.090 was still there.

[immi]

Hi willy
plausible explanation
thanks for helping to debug
immi

[immi]

Hi willy
plausible explanation
thanks for helping to debug

one more question:p15RoomInfluenceHC1 is from 0 to 10 like in datasheet or there is a typo?

immi

[micomat]

that sounds reasonable, since you have a heating curve value of just 0.2. Let me know about the outside wall isolation (cross section of your walls) please.

i have a low energy house (and a always freezing wife)
we have a 15cm outside insulation on the walls. in my eyes the booster is first allowed to work after a few days of very low temperature with the danger of the house is chilling out too much. i live in southern of bavaria (about 40km from fuessen) so we HAVE winter here

markus

[willybauss]

one more question:p15RoomInfluenceHC1 is from 0 to 10 like in datasheet or there is a typo?

looks like a typo. I can change it from 0till 100%.

[immi]

looks like a typo. I can change it from 0till 100%.

Hi Willy
In Both the engl. and german datasheet  is wrong 1..10. otherwise it makes no sense.
I do not use the parameter (at the time ), but I am starting to consider it for next winter.
Could you please explain in one sentence, what the parameter does, so that Markus documents  the wiki?
Maybe an example could be usefull, considering what happens with 0% and and what happens with your current setting.
Shall I modify the code in 00_THZ.pm from 0..10  to 0...100%?
Immi

[houseowner123]

Hi Tom,


if you don't succeed with the correction in this way (like it was im my case because of additional display in living room) let me know. I had to correct it by a user reading

Code Auswählen Erweitern


inside_temp:sGlobal {((split ' ',ReadingsVal("Mythz","sGlobal",0))[81]) - 0.6 }



Willy

Thanks, Willy! That is exactly what I had to do.  Correction was -2.6. Regarding usage: We live in an low energy house (KfW 55) too, built in late 2011. The first two years we used 2800 kWh. I then looked closer into options of saving. Most effective so far are the timer programs for day and night. I simply accept that it is little bit colder in the morning and start the day setting at 4 pm. Also the difference between day and night should not be more than 2 K. Because of the warm winter my goal is less than 2000 kWh this year.

Regarding booster: Booster usage does only depend on either bimodal point or the total time delay set for normal mode before booster sets in.  I have the bimodal point set at -10°C and only use booster stage I (if needed)  because most people agree that these setting are safe. But the bigger question: Is it really most efficient? With the help of FHEM THZ monitoring I would like to determine the outside temp where booster usage is more efficient than having the heat pump working endlessly.

@immi: Would room influence as 0-10 scale. It could be that the FEZ extra display translates this into percent but on the LWZ/THZ display it is a 0...10 scale, at least for my version. I think it is a smart idea to use room temp influence at setting 5 (50%) as a starting point. The heat production is then balanced between in-and outside temp. However I see the danger that it also could lead to unnecessary heating. It needs testing. In the end it depends how well your house is insulated and air-tightly packed.
Four things can acutely raise the room temp:
- use of fireplace
- use of kitchen oven
- low sun through big windows
- pure presence of people (2-3) in one room 
Under these circumstances room influence should slow down pump activity. Is there anybody else out there but Willy who has a room temp sensor installed?

Tom

[immi]

Hi Tom
>>  Would room influence as 0-10 scale. It could be that the FEZ extra display translates this into percent but on the LWZ/THZ display it is a 0...10 scale, at least for my version. I think it is a smart idea to use room temp influence at setting 5 (50%) as a starting point.

In the heatpump firmware there is a number from 0 to 100. In the display of my heatpump there is  0 to 100.
In the manual there is 0...10.

immi

[houseowner123]

Hi Tom
>>  Would room influence as 0-10 scale. It could be that the FEZ extra display translates this into percent but on the LWZ/THZ display it is a 0...10 scale, at least for my version. I think it is a smart idea to use room temp influence at setting 5 (50%) as a starting point.

In the heatpump firmware there is a number from 0 to 100. In the display of my heatpump there is  0 to 100.
In the manual there is 0...10.

immi

I guess then diffferent firmware versions have different scales here. Can you set the influence to something like 56% or only in decades?

Tom

[immi]

you can try 56%
--
set Mythz p15RoomInfluenceHC1 5.6

immi

[willybauss]

In the heatpump firmware there is a number from 0 to 100. In the display of my heatpump there is  0 to 100.
In the manual there is 0...10.

immi

same at my side

[willybauss]

Hi Willy
Could you please explain in one sentence, what the parameter does, so that Markus documents  the wiki?
Maybe an example could be usefull, considering what happens with 0% and and what happens with your current setting.
Shall I modify the code in 00_THZ.pm from 0..10  to 0...100%?
Immi

@ markus:
p15RoomInfluenceHC1 defines influence of room temperature on heating curve.
0 => heat curve follows outside temp only
30 => 30% influence of inside temp, 70% outside temp

[houseowner123]

@ markus:
p15RoomInfluenceHC1 defines influence of room temperature on heating curve.
0 => heat curve follows outside temp only
30 => 30% influence of inside temp, 70% outside temp

Willy,
Since you have the most experience with this. So the THZ/LWZ calculates then internally 2 heating curves, one only based on outside temp, the other only on inside temp and then weights the results based you chosen influence setting to come up with a resulting HeatSollTemp?

[willybauss]

@ houseowner123

I wonder how a KFW55 house can cool down by 2° over night? If I would switch the heat pump off in the evening I would not at all see any difference on the inside room temperature for lots of hours, since the stone floor (approx. 30 tons) keeps lots of energy.

When in the evening do you start night mode? I assume you switch to day setting at 4 am, not pm, right? Or is the house in night mode from last evening until afternoon? That would be the explanation for the big savings by using day/night mode.

Do you have additional solar cells on the roof? I don't - so far.

With the help of FHEM THZ monitoring I would like to determine the outside temp where booster usage is more efficient than having the heat pump working endlessly.

How will you do that? Can you share your thoughts about finding the right decision? Basically I believe that the heat pump's heat creation is more efficient that the booster always. Even in coldest winter nights it has at least a factor of 3x, while the booster is always on 1x. Limiting the booster to stage 1 is a good solution to avoid stopping the heat pump to work, just because the booster did its work too fast.

The setting of room influence is also related to the physical characteristics of your house, e.g. phase shift (=time delay between a temperature change happening outside and the point in time when it arrives on the room side). If your house is built from heavy stones you should keep the room influence low. Otherwise it can take too long to heat up, when the room sensor detects under temperature. Stones have a big heat storage capacity, needing lots of energy to heat them up - and the THZ has just 6kW ...

Another thing causing higher room temperatures is reading newspaper at night My lamp uses up to 150W, visible on the thermometer within 15 minutes.

Often forgotten influences:
- hydraulic adjustment (as I described above)
- use of room thermostats instead of open heating circles
- wrong spread of heat circle temperatures (=difference between flow temp and return temp); should be approx. 5° when using a underfloor heating

[willybauss]

Willy,
Since you have the most experience with this. So the THZ/LWZ calculates then internally 2 heating curves, one only based on outside temp, the other only on inside temp and then weights the results based you chosen influence setting to come up with a resulting HeatSollTemp?

Sorry, don't know how the calculation is really done in detail. Up to approx. February I used 30%, but when I started with the monitoring I saw that there's still heat pump activity during night, even if room temperature is too high. After switching to 50% this is just happening rarely.
You can check the heating curve screen dumps I posted yesterday. One of them is with 0%, the other one with 50%. The difference is ~4.8° in heatSetTemp.