THZ / LWZ Tecalor Stiebel Eltron Heizung

[houseowner123]

@ 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.

There are the differencse: No stones in my house, it is wooden based house (Fingerhaus) with multilayered thin insulation. Because of that, the ceiling is rather thin. Second, I have basement in which the temp is always much lower and I assume (though the basement is well insulated against the internal staircase) it works a bit like a heat sink.
Presence or absence is a room of 2 people accounts for 1K difference. If there are 6 people present in the house, I generally need no oven in the winter. Having overnight guest has therefore special (saving) benefits.

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.

Sorry, 4 pm the day mode starts

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

No, they will never amortize.

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.

That is what I believed until this winter during which we had three days with average temps of -10°C. The heat pump was struggling to even raise the temp if the heating circuit by 0.1K. I was watching it for 45 min. On the contrary, WW heating worked well. When I olwered bimodal point from -10°C to -6°C the daily usage dropped by 5 or 6 kWh. Even though the booster runs with 6 kWh, usage was lower. Well, maybe my LWZ needs mainainance but I believe there is an out side temp for which counts: 6 kWh * time x < 1.5 kWh * time y. That's what I would like to determine.

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 ...

Since our both houses have completely different physical characteristics, the ideal settings might differ too. I do not have a "stone buffer".

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

And I thought you're the king of energy efficiency here...

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

Not sure how to influence the spread. Mine is definitely lower. more like 3-4°.
Completely agree about the thermostats
hydraulic adjustment...For now I trust the setting the builder has provided me with. I also do not want the same temps in every room of the house. Bed rooms therefore have low flow rates, bath room and 3 living room circuits have how rates of flow.

thanks for the useful discussion, even though it is a bit off the forum topic.

Tom

[immi]

Hi Tom
>> thanks for the useful discussion, even though it is a bit off the forum topic.
I also like the discussion and I do not care if it is a little off topic.
Go on, share your experience and config setting.
The module development 00_THZ is running really fast also because I am learning more on the heatpump from you.

immi

[lwzler]

Hi Tom
>> thanks for the useful discussion, even though it is a bit off the forum topic.
I also like the discussion and I do not care if it is a little off topic.

Thanks for letting the discussion go on.

I also have a house with a balloon framing structure and a basement (Fingerhaus too ). As I didn't want to spent ~6k € extra  - which would never have amortized  - I "only" reached KfW62...
But I wouldn't count to much on those KfW rankings.

As the last winter wasn't really a winter, the heat pump didn't use the booster at al. So I have a lack of experience on this poitn. But what is driving me - besides of laziness  - in monitoring the heat pump, is to find a way to use my self-made solar energy in the best way for the heat pump.

About the booster and the compresser bivalent point.
For me it is plausible that the booster can work more efficient at certain levels higher than the given bivalency point. With the bosster you easliy can raise room temperatures 1-2K whereas the compressor has to struggle to get enough enery out of the air to manage to produce 0.1 - 0.5 K.
So this is also a point wehre it is usefull to know about the energy consumption of the heat pump, to be able to decide at which temperatures what form of energy production works most efficient.

[willybauss]

There are the differencse: No stones in my house, it is wooden based house (Fingerhaus) with multilayered thin insulation.

Basically same construction than mine, beside my 6cm thick stone floor where the underfloor heating is built in.

No, they will never amortize.

I thought so too and therefore filled the roof with PV cells. But meanwhile I see from the logged data that I coud save ~150€ p.a. with solar cells (warm water plus heating support). And meanwhile the government supports installation with up to 1500€, so the calculation might look different now.

When I olwered bimodal point from -10°C to -6°C the daily usage dropped by 5 or 6 kWh. Even though the booster runs with 6 kWh, usage was lower. Well, maybe my LWZ needs mainainance but I believe there is an out side temp for which counts: 6 kWh * time x < 1.5 kWh * time y. That's what I would like to determine.

sounds very interresting indeed

Not sure how to influence the spread. Mine is definitely lower. more like 3-4°.

Simply reduce power of the heat circuit pump - which additionally saves energy. To do so you need to remove the left front housing of the THZ. Then you will see the regulators on the water pumps. To ease it up I drilled a small hole into the housing, so I do no more need to remove it, to just turn the regulator.
And when the housing is removed anyway you can add some more isolation around the DHW container. This reduced the energy loss of the DHW container by 30 ... 40%. Water needs to heat up just once per day if nothing is used.

hydraulic adjustment...For now I trust the setting the builder has provided me with.

You will see as soon as you stop using the thermostats.

I also do not want the same temps in every room of the house.

Basically no problem to reduce a room's temperature, just reduce the flow. What not really works is a significantly higher temperature in e.g. bath room. With my setup its just possible to have it approx. 1° higher than the other rooms.


An additional very cheap solution to save energy: simply remove the outside temp sensor from north side of the house and mount it at the north eastern corner, so that sunshine can heat it up early in the morning. So you can tell the THZ that the sun will do the job for the rest of the day (if you have big windows on south and east side, like me). Check blue and black curves in attached screen shot. As soon as the sun shines on the sensor the heatSetTemp goes dow. Nevertheless the inside temp goes up during the day. On cloudy on foggy days it works as before.

[micomat]

for me, additional price for 5,2m² solar cells on the roof was 3000EUR after a hard negotiation...
AND i love it to see also on cloudy days (even in december) the DHW temp is climing on 50-60°C without having the DHW compressor working
we've got 5000EUR from the government for having the energy consumption reduced to KFW40 level

[willybauss]

AND i love it to see also on cloudy days (even in december) the DHW temp is climing on 50-60°C without having the DHW compressor working

flat panel or vaccum tube cells?

[micomat]

flat Panel. here are some hail Storms Every Summer

[lwzler]

for me, additional price for 5,2m² solar cells on the roof was 3000EUR after a hard negotiation...

Including the upgrade for the THZ to al SOL version?

AND i love it to see also on cloudy days (even in december) the DHW temp is climing on 50-60°C without having the DHW compressor working

On those days my PV produces al least ~10 kWh, that can be used for the compressor...so there has to be some maths whichs comes out cheaper after all.
Acutally I don't know...

Maybe for some of you this users-maintenance-manual which I found in a blog might be interesting:
http://hausnummer17.blogspot.de/2014/01/durchfuhrung-der-wartungsarbeiten-fur.html

[houseowner123]

for me, additional price for 5,2m² solar cells on the roof was 3000EUR after a hard negotiation...
AND i love it to see also on cloudy days (even in december) the DHW temp is climing on 50-60°C without having the DHW compressor working
we've got 5000EUR from the government for having the energy consumption reduced to KFW40 level

Impressive! I did not think the panels would work on cloudy days. Nevertheless, at the time the Sol option was too pricy. The panels were 4000 and the Sol version was 2000 € more. We already had the kfw55 benefit of 4000 with 303i and since we were heavily penalized for having a basement, I am not sure if we would have even reached kfw40 levels to get the extra 1000 € bonus. But I am glad it worked out for you. Good negotiation skills!

[willybauss]

I don't have solar cells, but I have the THZ with solar option (303 SOL), since it has different advantages too. So I plan to add solar panels to the southern wall sooner or later.

[immi]

Dear all
I was very diligent:
I uploaded v0.096 //////// tomorrow update and restart
changelog:
1) RoomInfluenceHC1 from 0 to 100%
2) lots of new energy parameters (I did not go downstairs to check them)

have fun
immi

[micomat]

Including the upgrade for the THZ to al SOL version?
On those days my PV produces al least ~10 kWh, that can be used for the compressor...so there has to be some maths whichs comes out cheaper after all.
Acutally I don't know...

yep, with all upgrades and so. btw, we also have 5kW solar power on the roof so i love sunny days.
and we also have a basement. a house without a basement is not a real house

immi, thanks a lot. will test and update the wiki today.

markus

[houseowner123]

Thanks, immi! 

Coming back to the modul..I have three questions:
Question 1: I am a little frustrated that the new heating parameters are never updated unless I do restart. Here is my config:

Code Auswählen Erweitern

attr Mythz interval_sGlobal 300
attr Mythz interval_sHistory 28800
attr Mythz interval_sHeatRecoveredDay 28800
attr Mythz interval_sHeatDHWDay 28800
attr Mythz event-on-change-reading .*

What I am doing wrong?

Second: Is there a way to count or better to add up the times of the activity for the pumps. So, when they active they are attributed the value 1; when inactive they get a zero. I would like to sum up per day the time of activity for heating circuit and the DWH pump (0:00-24:00). Why? sHistory rounds to the full hour which is great if you want to judge things over the course of a month. For the determination, when a booster beats the pump in energy consumption, this kind of finer time resolution is essential.

Third: How do you fill the headers of the diagrams (e.g. the heat curve) with all these nice reading. Willy has it too. What is the code for that?

Thank you so much!
Tom!

[immi]

Hi Tom
First: easy--> you get a periodic update for a reading only if you set in your config an interval or a AT. How shal THZ know how often you want to refresh?
Second: not a easy task
Third: easy --> read the wiki: http://www.fhemwiki.de/wiki/Plots_erzeugen

immi

[houseowner123]

First: easy--> you get a periodic update for a reading only if you set in your config an interval or a AT. How shal THZ know how often you want to refresh?

I am confused. The code line says there is an interval of 28800 seconds for both parameters. Why aren't they updated then at all. I don't understand.

Third: easy --> read the wiki: http://www.fhemwiki.de/wiki/Plots_erzeugen

I read this. The parameter is <TL>. That's all the instruction says. But how do get an actual reading in the title? Can you please provide just one plain example out of a gplot log? I figure out the rest.

immi