ᐅ Air-to-water heat pump combined with underfloor heating is not functioning properly
Created on: 22 Sep 2021 15:34
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_Ugeen_
Hello everyone,
We moved into our single-family house in the middle of the year and are now using our air-to-water heat pump (Daikin Altherma 3 R ECH2O) for the first time. In the rooms, we decided against the standard analog controllers and chose digital controllers instead. After several discussions with Daikin and the controller manufacturer, I now understand that a valve is only opened or closed when I want to increase the temperature or not.
With the Daikin system, I can set a target room temperature. According to Daikin, this target value does not represent the minimum temperature per room but rather the "preheating value," if I understand correctly. This value was previously set at 23°C (73°F).
In the bedroom, I set the digital controller so that heating only starts when the temperature drops below 18°C (64°F). Despite this setting, the room temperature has always been 22-23°C (72-73°F), although the digital controller shows that heating is off. After changing the target room temperature from 23 to 21°C (73 to 70°F), it got a bit cooler. However, in the bathroom, heating is supposed to activate below 23°C (73°F). The temperature there is 22°C (72°F), and the digital controller indicates that heating is active. Yet, the room does not get warmer, and the floor heating does not noticeably warm up either.
Conclusion: I still have not understood the logic behind the target room temperature setting. In our previous apartment, we also had underfloor heating with analog controllers that I could adjust higher or lower. That worked wonderfully, and I felt like I could control the temperature. Here, with the air-to-water heat pump, I don’t have that feeling. Also, the towel warmers do not get truly warm (only lukewarm), which Daikin says is normal even when the dial is set to 5. This is apparently because it is a low-temperature heat pump. Without the electric booster to warm the towel warmers, they are essentially ineffective. Is this normal? Could there be an error, or do I need to use completely different settings?
If anyone has experience with this topic, I would greatly appreciate your feedback. At the moment, I feel a bit lost on this subject.
We moved into our single-family house in the middle of the year and are now using our air-to-water heat pump (Daikin Altherma 3 R ECH2O) for the first time. In the rooms, we decided against the standard analog controllers and chose digital controllers instead. After several discussions with Daikin and the controller manufacturer, I now understand that a valve is only opened or closed when I want to increase the temperature or not.
With the Daikin system, I can set a target room temperature. According to Daikin, this target value does not represent the minimum temperature per room but rather the "preheating value," if I understand correctly. This value was previously set at 23°C (73°F).
In the bedroom, I set the digital controller so that heating only starts when the temperature drops below 18°C (64°F). Despite this setting, the room temperature has always been 22-23°C (72-73°F), although the digital controller shows that heating is off. After changing the target room temperature from 23 to 21°C (73 to 70°F), it got a bit cooler. However, in the bathroom, heating is supposed to activate below 23°C (73°F). The temperature there is 22°C (72°F), and the digital controller indicates that heating is active. Yet, the room does not get warmer, and the floor heating does not noticeably warm up either.
Conclusion: I still have not understood the logic behind the target room temperature setting. In our previous apartment, we also had underfloor heating with analog controllers that I could adjust higher or lower. That worked wonderfully, and I felt like I could control the temperature. Here, with the air-to-water heat pump, I don’t have that feeling. Also, the towel warmers do not get truly warm (only lukewarm), which Daikin says is normal even when the dial is set to 5. This is apparently because it is a low-temperature heat pump. Without the electric booster to warm the towel warmers, they are essentially ineffective. Is this normal? Could there be an error, or do I need to use completely different settings?
If anyone has experience with this topic, I would greatly appreciate your feedback. At the moment, I feel a bit lost on this subject.
Tolentino schrieb:
Not a bad idea, since there is no switch for that. You really have to disconnect the cables from the motors. Not everyone would just do that.Or take a look in the fuse box: In our case, the control valves are protected by separate fuses.
D
Daniel-Sp22 Sep 2021 22:50Tolentino schrieb:
Not a bad idea, since there is no switch for that. You actually have to disconnect the cables from the actuators. Not everyone does that just like that.
Step one should be to visit the heating engineer. They should perform a hydraulic balancing if it hasn’t been done already. Then you can look up “thermal balancing” here or generally on the internet. This is a topic that can take several days or even weeks, as underfloor heating—as already mentioned further above by @michert—responds very slowly.
If your heating engineer and electrician have communicated, the actuators are on a separate circuit breaker. Then you only need to switch off the breaker and remove the actuators. This saves money over the course of the year.
Furthermore, a lot of information is missing. Is there a heat load calculation, preferably room-by-room? Has the calculation of heating surfaces been done (pipe spacing, flow rate for NAT—nominal air temperature)? Were desired temperatures requested for the room-specific heat load calculation? Has a maximum flow temperature for NAT been agreed upon? Based on many stories here in construction with a general contractor, I suspect this has not happened, and at best there is a standard design of the underfloor heating system from the system manufacturer following a fixed scheme with a flow temperature of 35°C (95°F).
What does the hydraulics of the system look like before the heating circuit valve? Does the heat pump heat directly into the underfloor heating (optimal situation), or is there a heating circuit buffer tank installed, and how is it built in? There are many potential efficiency killers here, such as separation buffers, combined or stratified buffer tanks, and bypass valves.
If you have thoroughly studied the topic and are familiar with your system, you can generally achieve efficient operation, but you have to let go of the expectation that you can achieve something meaningful in every room simply by operating a room thermostat with a brief turn. A heat pump with underfloor heating in a new build means once setting desired temperatures for the individual rooms (within narrow limits), adjusting and optimizing the system during the first two winters, and only dealing with the heating system again when replacing the heat pump in hopefully more than 15 years.
I don’t see the decision against district heating as a mistake if your goal is also to reduce heating costs. District heating combined with underfloor heating in a new build is also a slow-responding system.
Do you have shading on the windows?
Regards
R
RotorMotor22 Sep 2021 23:45How is the house insulated?
A good thermal envelope makes significant temperature differences inside virtually impossible.
In that case, you would have to insulate the interior walls, which is generally not done.
A good thermal envelope makes significant temperature differences inside virtually impossible.
In that case, you would have to insulate the interior walls, which is generally not done.
Tolentino schrieb:
Ultimately, the recommendation here is to either ignore the ERR (individual room control) by setting it to permanent maximum or even deactivate it by unscrewing the actuators on the heating circuit manifold or cutting the power (with power off: open position) I plan to set the ERRs to permanent maximum.
Is this behavior the same as the "power off option," or would it be better to actually remove the actuators?
Am I correct in understanding that there are different versions regarding the position (open or closed) when power is cut?
netuser schrieb:
Do I understand correctly that there are different versions regarding the state (OPEN or CLOSED) during a power failure?Yes, exactly, that exists. I therefore disabled the actuators because otherwise, I would have to supply them with power continuously to keep them open.
Ugeen, before regretting the district heating system, take some time to learn about the topic, and then I believe you will come to appreciate the advantages of the existing system. You just need to detach yourself from previous habits and the corresponding logic. After that, you will likely experience even better comfort than you were used to before.
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