ᐅ Is it possible to optimize the heating system after performing hydraulic balancing?
Created on: 13 May 2021 15:19
K
kati1337
Hello everyone!
I am encountering topics where I have very little knowledge so far, but now need to deal with them.
Basically, we have an air-to-water heat pump (Tecalor THZ 504) and underfloor heating.
Before the handover of the house, our heating installer performed a "hydraulic balancing," for which there is documentation, and this was apparently also important for the KfW funding.
Therefore, the plumbing consultant once told us that we should actually not change anything on the heating system ourselves / maybe even are not allowed to (?), because that was the basis for the KfW subsidy.
Now, of course, we live in this house and in practice have a few minor issues with the heating.
Overall, the temperature in the house was comfortable during the cold months. As spring approaches, I find the house slightly too warm. As far as I know, you need to adjust the "heating curve" a bit. Simply turning down the temperature manually probably isn’t sensible, because the heat pump controls the indoor temperature based on the outdoor temperature, and since it worked fine in winter, I assume something in this ratio is off. If I lower the temperature myself now, then I’d have to raise it again when it gets colder — that just doesn’t seem reasonable to me.
Furthermore, upstairs it is constantly too cold in the bathroom (significantly so) and a little too warm in the bedroom.
This is related to the fact that, in agreement with the heating installer, we always turn the room thermostats fully up (anything else would be wasting energy, as we were also told here in the forum). Otherwise, they keep clicking constantly, which is annoying (especially at night). In the bathroom, even fully turned up, there just doesn’t seem to be enough heat, at least from my perspective. The bedroom heats up quickly and becomes too warm; we actually prefer to sleep in a cooler room.
Is there a way to adjust this so that the bathroom becomes warmer and the bedroom does not get too warm, without turning down the thermostats? For example, by changing something at the manifold?
And are we allowed to do this even though hydraulic balancing was carried out? (I still don’t really understand what that means.)
I also recently found a planning note from the company that installed the underfloor heating in the documentation, which says “reduced output” for the bathroom of 49W, indicating that additional heating elements would be needed. :/ However, we don’t have those. During the selection process, we decided not to include a towel radiator because we were told it wouldn’t get warm enough anyway, since the flow temperature is often below 30°C (86°F).
What we didn’t consider or know at the time was that it probably would have helped to heat the bathroom overall.
I am encountering topics where I have very little knowledge so far, but now need to deal with them.
Basically, we have an air-to-water heat pump (Tecalor THZ 504) and underfloor heating.
Before the handover of the house, our heating installer performed a "hydraulic balancing," for which there is documentation, and this was apparently also important for the KfW funding.
Therefore, the plumbing consultant once told us that we should actually not change anything on the heating system ourselves / maybe even are not allowed to (?), because that was the basis for the KfW subsidy.
Now, of course, we live in this house and in practice have a few minor issues with the heating.
Overall, the temperature in the house was comfortable during the cold months. As spring approaches, I find the house slightly too warm. As far as I know, you need to adjust the "heating curve" a bit. Simply turning down the temperature manually probably isn’t sensible, because the heat pump controls the indoor temperature based on the outdoor temperature, and since it worked fine in winter, I assume something in this ratio is off. If I lower the temperature myself now, then I’d have to raise it again when it gets colder — that just doesn’t seem reasonable to me.
Furthermore, upstairs it is constantly too cold in the bathroom (significantly so) and a little too warm in the bedroom.
This is related to the fact that, in agreement with the heating installer, we always turn the room thermostats fully up (anything else would be wasting energy, as we were also told here in the forum). Otherwise, they keep clicking constantly, which is annoying (especially at night). In the bathroom, even fully turned up, there just doesn’t seem to be enough heat, at least from my perspective. The bedroom heats up quickly and becomes too warm; we actually prefer to sleep in a cooler room.
Is there a way to adjust this so that the bathroom becomes warmer and the bedroom does not get too warm, without turning down the thermostats? For example, by changing something at the manifold?
And are we allowed to do this even though hydraulic balancing was carried out? (I still don’t really understand what that means.)
I also recently found a planning note from the company that installed the underfloor heating in the documentation, which says “reduced output” for the bathroom of 49W, indicating that additional heating elements would be needed. :/ However, we don’t have those. During the selection process, we decided not to include a towel radiator because we were told it wouldn’t get warm enough anyway, since the flow temperature is often below 30°C (86°F).
What we didn’t consider or know at the time was that it probably would have helped to heat the bathroom overall.
T
T_im_Norden15 May 2021 14:07The adjustment would only be temporary; when it gets colder again, you set it back.
The 20 degrees Celsius (68°F) setting on the heat pump is a theoretical value since it does not know the temperature inside the rooms.
This value is used internally by the heat pump to adjust the supply and return temperatures in relation to the outside temperature.
Were the flow rate (L/min) readings taken directly from the manifold or from the documents?
“I don’t know how that can be achieved since we have only one temperature set on the heat pump (currently set to 20°C (68°F)).”
Different room temperatures are achieved with a constant supply temperature by varying the volume of water passing through. Rooms that need to be warmer require more water, others less. The temperature set on the heat pump is not the expected room temperature (see above).
https://www.hausbau-forum.de/threads/zentraler-raumtemperaturregler-fuer-err-der-fbh.35503/page-7#post-417306
The 20 degrees Celsius (68°F) setting on the heat pump is a theoretical value since it does not know the temperature inside the rooms.
This value is used internally by the heat pump to adjust the supply and return temperatures in relation to the outside temperature.
Were the flow rate (L/min) readings taken directly from the manifold or from the documents?
“I don’t know how that can be achieved since we have only one temperature set on the heat pump (currently set to 20°C (68°F)).”
Different room temperatures are achieved with a constant supply temperature by varying the volume of water passing through. Rooms that need to be warmer require more water, others less. The temperature set on the heat pump is not the expected room temperature (see above).
https://www.hausbau-forum.de/threads/zentraler-raumtemperaturregler-fuer-err-der-fbh.35503/page-7#post-417306
D
Daniel-Sp15 May 2021 14:12Then please take a picture of the heating circuit manifold.
You achieve different temperatures in the rooms by adjusting the flow rates.
You can also set the flow rates directly on the heating circuit manifold. Reduce the flow rate on the manifold for the bedroom, then you can leave the room sensor set to maximum.
Maybe you can allow a bit more flow in the bathroom through the manifold.
At that point, you are already in the middle of the hydraulic balancing process. The ideal time for this has actually passed, but some adjustment in the bedroom is still possible.
You achieve different temperatures in the rooms by adjusting the flow rates.
You can also set the flow rates directly on the heating circuit manifold. Reduce the flow rate on the manifold for the bedroom, then you can leave the room sensor set to maximum.
Maybe you can allow a bit more flow in the bathroom through the manifold.
At that point, you are already in the middle of the hydraulic balancing process. The ideal time for this has actually passed, but some adjustment in the bedroom is still possible.
kati1337 schrieb:
I also found a planning note from the installing company in the documentation I recently received regarding the underfloor heating, stating a "reduced output" of 49W for the bathroom, requiring additional heating surfaces. :/ However, we do not have those. During the selection process, we decided not to install the towel radiator, reasoning that it wouldn’t get warm enough anyway due to often having a flow temperature below 30°C (86°F).
What we didn’t consider or know at the time was that it probably would have helped to heat the bathroom overall more effectively. That’s true.
I have also frequently read that bathrooms often cause issues because there is no underfloor heating installed under the bathtub and shower, so the heated surface compared to the room volume is very small. In some cases (including mine), there are also ventilation openings that draw cooler air from adjacent rooms into the bathroom.
But the 1.8 m (5 ft 11 in) tall towel radiator without an active heating cartridge barely makes a noticeable difference here, even with a somewhat higher flow temperature. The most comfortable effect only occurs when using the heating cartridge recommended to us and included in the installation (600 W). Of course, that then costs almost $0.20 per hour (with a noticeable effect after 10-15 minutes), whereas maintaining the flow temperature required for a similarly comfortable bathroom would also incur some cost.
D
Deliverer20 May 2021 12:29If you find it too warm during the transitional period, you need to adjust the heating curve to be steeper, as mentioned earlier.
The curve shows the lowest supply temperature at the highest outdoor temperature (OT) in the lower left (before the heating turns off). At the upper right, it shows the highest supply temperature at the lowest outdoor temperature (LOT).
To make the curve steeper, there are two options. Depending on your heat pump, you can change all or only some of the values:
1: You can lower the base temperature. This is the supply temperature at which the heating starts. Before: 18°C OT = 25°C supply temperature, after: 18°C OT = 23°C supply temperature.
(You might also be able to reduce the start OT, meaning the heating only starts at colder outdoor temperatures. If the supply temperature remains the same, this also results in a steeper curve.)
2: You can directly adjust the "steepness" of your curve. For new builds, the value is usually around 0.6. You can increase it to 0.7 initially. However, since this usually changes the end temperatures, you will need to perform a parallel shift downwards afterward—probably by lowering the supply temperature at both the start and end OT. Sometimes there are also offsets that you can adjust.
(I’m not a professional and have only done this twice myself. If I got any signs reversed or used incorrect terms, please correct me!)
Regarding the bathroom: That is always a tricky issue. The 49-watt undersupply is not a problem since the bathroom is designed for a higher room temperature than other rooms. After a successful balancing, the temperature in the bathroom should be noticeably warmer than in the other rooms. If it’s not, first make sure the bathroom is getting the maximum flow. It’s best to unscrew the flow restrictor (ERR) and manually set the maximum flow to the bathroom on the manifold.
If the bathroom already has maximum flow, there is only one unpleasant solution: the heating curve must be raised overall. At the same time, ALL other rooms must be slightly throttled (manually at the manifold) until their temperatures are balanced again.
But this will make your heat pump operate a few percentage points less efficiently (due to the higher temperature), resulting in significantly higher electricity consumption, just so you can have a bit more coziness for 30 minutes a day. I wouldn’t recommend this. Installing a small infrared heater that only turns on when the bathroom is in use would be more reasonable.
One more thing: Is the bathroom maybe ventilated more heavily? Either with controlled ventilation or frequent tilt windows? Or is the door often left open? Both of these will lower the temperature even if the heating is set correctly…
Finally: Since you are not using the flow restrictors (ERR), which is good, I would switch them off electrically or even remove them entirely.
The curve shows the lowest supply temperature at the highest outdoor temperature (OT) in the lower left (before the heating turns off). At the upper right, it shows the highest supply temperature at the lowest outdoor temperature (LOT).
To make the curve steeper, there are two options. Depending on your heat pump, you can change all or only some of the values:
1: You can lower the base temperature. This is the supply temperature at which the heating starts. Before: 18°C OT = 25°C supply temperature, after: 18°C OT = 23°C supply temperature.
(You might also be able to reduce the start OT, meaning the heating only starts at colder outdoor temperatures. If the supply temperature remains the same, this also results in a steeper curve.)
2: You can directly adjust the "steepness" of your curve. For new builds, the value is usually around 0.6. You can increase it to 0.7 initially. However, since this usually changes the end temperatures, you will need to perform a parallel shift downwards afterward—probably by lowering the supply temperature at both the start and end OT. Sometimes there are also offsets that you can adjust.
(I’m not a professional and have only done this twice myself. If I got any signs reversed or used incorrect terms, please correct me!)
Regarding the bathroom: That is always a tricky issue. The 49-watt undersupply is not a problem since the bathroom is designed for a higher room temperature than other rooms. After a successful balancing, the temperature in the bathroom should be noticeably warmer than in the other rooms. If it’s not, first make sure the bathroom is getting the maximum flow. It’s best to unscrew the flow restrictor (ERR) and manually set the maximum flow to the bathroom on the manifold.
If the bathroom already has maximum flow, there is only one unpleasant solution: the heating curve must be raised overall. At the same time, ALL other rooms must be slightly throttled (manually at the manifold) until their temperatures are balanced again.
But this will make your heat pump operate a few percentage points less efficiently (due to the higher temperature), resulting in significantly higher electricity consumption, just so you can have a bit more coziness for 30 minutes a day. I wouldn’t recommend this. Installing a small infrared heater that only turns on when the bathroom is in use would be more reasonable.
One more thing: Is the bathroom maybe ventilated more heavily? Either with controlled ventilation or frequent tilt windows? Or is the door often left open? Both of these will lower the temperature even if the heating is set correctly…
Finally: Since you are not using the flow restrictors (ERR), which is good, I would switch them off electrically or even remove them entirely.
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