ᐅ Heat pump is not compatible with a hydronic (water-heated) fireplace.
Created on: 20 Oct 2023 18:54
J
Jessica388
Hello everyone,
I hope someone here can help us because our heating engineer doesn’t seem to be able to…
Key data
New build 2022 with 250 m² (2,691 ft²)
Heat pump Viessmann Vitocal 200-A
Multifunction storage tank MFS1000S
Water-heated stove with heating capacity on the water side of 8 kW
Photovoltaic system
Electric heating element
I am attaching the schematic of the storage tank layout.
The stove was initially connected under “old” and now it has been modified.
Everything works fine as long as the underfloor heating is off.
When the underfloor heating is on, our hot water temperature doesn’t exceed about 55°C (131°F).
When the underfloor heating is off, the temperature ranges between 65–75°C (149–167°F), either via the electric heating element during sunshine or by stoking the stove.
Now, however, this energy seems to be wasted. It can’t be that the underfloor heating requires 70°C (158°F) supply temperature to achieve a flow temperature of 35°C (95°F), right? The return water is only slightly cooler. So the water should only need to be heated by a maximum of 5°C (9°F).
We assume either a) something is still connected incorrectly, or b) the cold water from the underfloor heating causes such circulation that the hot water cools down within minutes.
What can be done about this?
Has anyone experienced similar problems?
Normally, we should almost run without electric power, but currently the heat pump switches on almost every hour to heat hot water…
I hope someone here can help us because our heating engineer doesn’t seem to be able to…
Key data
New build 2022 with 250 m² (2,691 ft²)
Heat pump Viessmann Vitocal 200-A
Multifunction storage tank MFS1000S
Water-heated stove with heating capacity on the water side of 8 kW
Photovoltaic system
Electric heating element
I am attaching the schematic of the storage tank layout.
The stove was initially connected under “old” and now it has been modified.
Everything works fine as long as the underfloor heating is off.
When the underfloor heating is on, our hot water temperature doesn’t exceed about 55°C (131°F).
When the underfloor heating is off, the temperature ranges between 65–75°C (149–167°F), either via the electric heating element during sunshine or by stoking the stove.
Now, however, this energy seems to be wasted. It can’t be that the underfloor heating requires 70°C (158°F) supply temperature to achieve a flow temperature of 35°C (95°F), right? The return water is only slightly cooler. So the water should only need to be heated by a maximum of 5°C (9°F).
We assume either a) something is still connected incorrectly, or b) the cold water from the underfloor heating causes such circulation that the hot water cools down within minutes.
What can be done about this?
Has anyone experienced similar problems?
Normally, we should almost run without electric power, but currently the heat pump switches on almost every hour to heat hot water…
D
Daniel-Sp25 Oct 2023 11:28Hello,
Is the radiator supplied from the same mixing circuit as the underfloor heating, or does it have its own separate mixing circuit?
Is the radiator supplied from the same mixing circuit as the underfloor heating, or does it have its own separate mixing circuit?
B
Buchsbaum25 Oct 2023 11:39Well, I would expect to be able to control the temperature individually in each room with any heating system, regardless of the type. Who wants the same temperature in the bedroom as in the bathroom?
Especially with such a costly investment.
In this particular case, the entire heating system concept probably needs to be reconsidered. But at least it’s a heat pump.
It will probably only run at night using clean green electricity from the photovoltaic system.
Especially with such a costly investment.
In this particular case, the entire heating system concept probably needs to be reconsidered. But at least it’s a heat pump.
It will probably only run at night using clean green electricity from the photovoltaic system.
D
Daniel-Sp25 Oct 2023 11:49This has nothing to do with the heat generator itself. The heat distributes within the thermal envelope, especially if the room doors are open. If you want a room to be particularly warm or cool, you need to isolate it from the others. Small differences in temperature are possible, but 18°C (64°F) in the bedroom and 24°C (75°F) or more in the adjacent bathroom will be difficult. This is even more true the better insulated the house is.
R
Radfahrer25 Oct 2023 12:01Daniel-Sp schrieb:
This has nothing to do with the heat generator at first. The heat distributes itself within the thermal envelope, especially when the interior doors are open. If you want a room to be particularly warm or cool, you have to isolate it from the others. Small differences in temperature are possible, but 18°C (64°F) in the bedroom and 24°C (75°F) or more in the adjoining bathroom will be difficult. This applies even more the better insulated the house is. That is only partly true.
I have 24°C (75°F) in the bathroom and at most 18°C (64°F) in the bedroom next to it (except in summer).
In the living room, I have a slightly higher temperature than in the kitchen, even though there is no wall between them.
This works with radiant heat.
WilderSueden schrieb:
We decided not to install a towel radiator and manage just fine without it. I also don’t understand what you all do in the bathroom that requires it to be 24 degrees. You’re not standing around naked forever—you just dry off and get dressed, right? We never actually turned it on 🙂
Technically, it was required. It’s mounted behind the door on the wall and doesn’t bother anyone. It also didn’t cost a fortune.
B
Buchsbaum25 Oct 2023 12:16That exactly describes the problem.
Often, a homeowner who is building a new house does not even know the difference between convective and radiant heat. They come from a rental apartment with radiators and then have to realize how different underfloor heating feels.
There is simply no direct heat source anymore. In the past, they could turn up the radiator thermostat, and within 5 minutes the room temperature would be a few degrees warmer. Of course, that doesn’t work with a heat pump and underfloor heating.
However, not everyone likes it. Personally, I don’t either. My feet are always warm, and I don’t like that constant heat from below. It is even said to promote varicose veins and similar conditions. So, from a health perspective, underfloor heating is not always beneficial.
I do like it very much in the bathroom, where it also makes sense. But I don’t need it in the kitchen.
And just installing a heat pump with the associated underfloor heating in a new build because it is standard and everyone does it—I don’t think that is the right approach.
Often, a homeowner who is building a new house does not even know the difference between convective and radiant heat. They come from a rental apartment with radiators and then have to realize how different underfloor heating feels.
There is simply no direct heat source anymore. In the past, they could turn up the radiator thermostat, and within 5 minutes the room temperature would be a few degrees warmer. Of course, that doesn’t work with a heat pump and underfloor heating.
However, not everyone likes it. Personally, I don’t either. My feet are always warm, and I don’t like that constant heat from below. It is even said to promote varicose veins and similar conditions. So, from a health perspective, underfloor heating is not always beneficial.
I do like it very much in the bathroom, where it also makes sense. But I don’t need it in the kitchen.
And just installing a heat pump with the associated underfloor heating in a new build because it is standard and everyone does it—I don’t think that is the right approach.
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