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.
opalau schrieb:
Yes, exactly, those do exist. I turned off the actuators because otherwise I would have to power them continuously to keep them open.Tolentino mentioned that there are motors that remain open without power. How can you possibly identify which type is installed? 🙂
Tolentino schrieb:
Not necessarily. Of course, you can turn down the flow rate at the hydraulic balancing valve (HKV) for the bedroom until you reach your desired temperature.Since I’m not very familiar with this, I don’t know exactly where I need to adjust anything. Where do I set the flow rate?Tolentino schrieb:
Not a bad point, because there is no switch for that. You actually have to disconnect the cables from the actuators. Not everyone does that lightly. The first step should be to contact the heating installer. They should perform a hydraulic balancing if it hasn’t been done yet. Then you can look up "thermal balancing" here or on the internet. This is a topic that can take several days or even weeks, because as mentioned above by @michert, underfloor heating reacts very slowly.I’ll have to bring that up during the first maintenance.Tolentino schrieb:
I don’t think so. District heating has a clear advantage, which is space-saving in the utility room.
Disadvantages are dependency on a monopolistic supplier, specifically:
- Financially
- Technically
As well as higher consumption costs and inefficient heating system.
See above, "thermal balancing."
Otherwise, this requires people who are more than just well-informed amateurs.
Maybe @Daniel-Sp will check back here; he knows quite a bit about this. Since the air-to-water heat pump has to activate the electric heating element above a certain temperature—which also uses electricity—as well as the additional electric supply for the towel radiators in the bathrooms, this doesn’t sound like an inexpensive solution. Plus, we don’t have a solar system yet. However, one is planned for the future.opalau schrieb:
Or check the electrical panel: in our case, the control valves are on separate circuit breakers.Same with us.
Daniel-Sp schrieb:
Once your heating technician and electrician have coordinated, the actuators will be connected to their own circuit breaker. Then you only need to switch off the breaker and remove the actuators. This also saves money over the course of the year.So, I always have to go to the heating manifold and turn something there? As a complete beginner, I’m afraid of breaking something rather than fixing it.Daniel-Sp schrieb:
Furthermore, a lot of information is missing. Is there a heat load calculation, broken down by room? Calculation of the heating surfaces (pipe spacing, flow rate for low-temperature heating (NAT))? Were desired room temperatures recorded for the room-specific heat load calculation? Was a maximum supply water temperature for the low-temperature system agreed upon? From many stories here about building with general contractors, I suspect none of this was done, and at best there was a pro forma design of the underfloor heating based on the manufacturer’s standard system layout with a supply temperature of 35°C (95°F).These details were not discussed with us. What does NAT mean?Daniel-Sp schrieb:
What does the hydraulics of the system look like before the hydraulic balancing valve (HKV)? Does the heat pump feed directly into the underfloor heating (optimal situation), or is there a heating circuit buffer tank added? What type? Many efficiency killers lurk here, such as hydraulic separators, combination buffers/stratified tanks, or bypass valves.
If you have read up well and become familiar with your system, you can usually achieve efficient operation. But you have to abandon the idea of achieving much by simply turning a room thermostat briefly in each room. Heat pumps with underfloor heating in new buildings mean setting desired temperatures for each room (within narrow limits), commissioning and optimizing the system during the first two winters, and only revisiting heating setup when replacing the heat pump after hopefully more than 15 years.Honestly, I’m not sure. My gut feeling says the heat pump heats directly into the underfloor heating. I currently don’t understand where else I can set desired room temperatures if not on the temperature controller. Is it also directly on the hydraulic balancing valve? How do I know exactly how to adjust the temperature there?
Daniel-Sp schrieb:
I don’t see rejecting district heating as a mistake, especially if you’re considering heating costs. Even district heating combined with underfloor heating in a new building is a slow-reacting system.
Do you have shading on the windows?
RegardsYes, we do. We have exterior roller shutters.RotorMotor schrieb:
How is the house insulated?
A good thermal envelope basically makes large temperature differences inside impossible.
Then you would have to insulate the interior walls, which normally is never done.Unfortunately, not at all. We were poorly advised here as well. We only have 24 cm (9.5 inches) solid bricks plastered over, no additional insulation. At the time, we had no knowledge and were told this was sufficient. Today I see it completely differently, but at this point the damage is done.netuser schrieb:
_Ugeen_, before you start regretting district heating, just learn a bit more about the topic and then I think you will come to appreciate the advantages of your existing system. You just have to break free from previous habits and the associated logic. Afterwards, you will probably experience better comfort than you are used to.Maybe so. Among other reasons, we decided on the air-to-water heat pump because we were told it could cool down by 6 to 8 degrees Celsius (11 to 14°F). I didn’t notice that at all this summer. A dedicated air conditioning unit might have been the better solution here.This clearly shows that you should not rely solely on others but rather actively inform yourself. No one here can meaningfully explain what you want to know. First, you need to take the initiative yourself. Please search for hydraulic or thermal balancing in connection with an air-to-water heat pump.
You can spend 2-3 days reading up on it, then provide the requested information here and ask targeted questions.
You can spend 2-3 days reading up on it, then provide the requested information here and ask targeted questions.
_Ugeen_ schrieb:
Among other reasons, we chose the air-to-water heat pump because we were assured that the cooling function would lower the temperature by 6-8 degrees. That was definitely incorrect advice, sorry for you! Realistically, it will be 2-4°C (36-39°F). Did you even confirm that a cooling function is included?
As I have recently learned, it also depends on having the correct room thermostats (RTs), which need to be compatible with it...
We also moved in at the end of January. We have an air-to-water heat pump with underfloor heating and a photovoltaic system.
I experimented for about 14 days until I found the right flow temperature for the air-to-water heat pump.
After that, I set all the radiators (ERR) fully on, except the one in the bedroom, which I turned down almost completely. This way, the bedroom doesn’t heat up as much, and all the other rooms maintain a consistent, comfortable temperature. The bathrooms also have towel radiators. These only get lukewarm, but that is enough to dry the towels overnight or during the day. The electric heater in my air-to-water heat pump only activates at around -15 to -20°C (5 to -4°F). So, it didn’t turn on last winter.
The combination with the photovoltaic system works great. Since March, I have hardly drawn any electricity from the grid. Even now, my system still powers our house 100% off-grid.
I experimented for about 14 days until I found the right flow temperature for the air-to-water heat pump.
After that, I set all the radiators (ERR) fully on, except the one in the bedroom, which I turned down almost completely. This way, the bedroom doesn’t heat up as much, and all the other rooms maintain a consistent, comfortable temperature. The bathrooms also have towel radiators. These only get lukewarm, but that is enough to dry the towels overnight or during the day. The electric heater in my air-to-water heat pump only activates at around -15 to -20°C (5 to -4°F). So, it didn’t turn on last winter.
The combination with the photovoltaic system works great. Since March, I have hardly drawn any electricity from the grid. Even now, my system still powers our house 100% off-grid.
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