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.
Well, that’s exactly what the heat recovery system is supposed to do. It warms the cooler outside air using the heat from the exhaust air.
You might want to check the documentation of your Lunos system to see if it has a bypass function. This would allow cooler air to be directed indoors, bypassing the heat exchanger.
You might want to check the documentation of your Lunos system to see if it has a bypass function. This would allow cooler air to be directed indoors, bypassing the heat exchanger.
Tolentino schrieb:
Well, that’s exactly what heat recovery is designed to do. It warms the cooler outside air using the heat from the exhaust air.
You could check the documentation for your Lunos system to see if it has a bypass function. This allows cooler air to be brought inside by bypassing the heat exchanger. Thanks for the information. A bypass function is available. I will take a closer look at that.
So, it turned out that the lower valves in the heating manifold were not set for individual temperature control. The heating was running at full power in all rooms the entire time. The flow rate, I believe that’s what it was called, was also adjusted. I will now monitor the situation and make further adjustments if necessary.
A
Alessandro6 Oct 2021 10:28Please take a photo of the entire heating system in the utility room/cellar and upload it here.
A thermostat (whether digital or analog) only opens or closes the heating circuit for the respective room. So, you either have warm water flowing through the heating circuit or no water flowing at all.
Your air-to-water heat pump generates a water flow (usually measured in L/min). This is the amount of water that returns from the heating circuit back to the heat pump to be reheated and then flows as supply water to the heating distribution manifold. In my case, this is about 1200 L/min (317 gallons per minute).
An air-to-water heat pump requires a minimum water flow to, for example, defrost the heat exchanger during freezing temperatures.
If you “shut down” too many heating circuits (and therefore reduce the water flow) through the thermostats, the air-to-water heat pump pushes water against the heating distribution manifold, which cannot absorb that volume of water. You can imagine it like pressing a garden hose closed while water is flowing at full force. The heat pump will then go into error mode.
I also spent a long time figuring out the hydraulics to get it right because, for a heating engineer, only one thing counts: that the house gets warm.
In my system, there is a second buffer tank in the hydraulics to counteract the “shutting down” of the water flow. This is not optimal in terms of efficiency but, if properly designed, can protect the operation of the heat pump.
A thermostat (whether digital or analog) only opens or closes the heating circuit for the respective room. So, you either have warm water flowing through the heating circuit or no water flowing at all.
Your air-to-water heat pump generates a water flow (usually measured in L/min). This is the amount of water that returns from the heating circuit back to the heat pump to be reheated and then flows as supply water to the heating distribution manifold. In my case, this is about 1200 L/min (317 gallons per minute).
An air-to-water heat pump requires a minimum water flow to, for example, defrost the heat exchanger during freezing temperatures.
If you “shut down” too many heating circuits (and therefore reduce the water flow) through the thermostats, the air-to-water heat pump pushes water against the heating distribution manifold, which cannot absorb that volume of water. You can imagine it like pressing a garden hose closed while water is flowing at full force. The heat pump will then go into error mode.
I also spent a long time figuring out the hydraulics to get it right because, for a heating engineer, only one thing counts: that the house gets warm.
In my system, there is a second buffer tank in the hydraulics to counteract the “shutting down” of the water flow. This is not optimal in terms of efficiency but, if properly designed, can protect the operation of the heat pump.
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