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…
A
Allthewayup21 Oct 2023 12:55According to which standard was the house built? We were advised against using a water-based fireplace on all sides in our house. The combination of underfloor heating, heat pump, and water-based fireplace is considered "difficult to manage," and comments like "pearls before swine in a low-energy house" were made. Nevertheless, we have pre-installed all the pipes but will move in without the fireplace for now and wait 2–3 years. In the end, we thought going "all in" would be harder to undo than upgrading later. Wishing you the best of luck finding the ideal setup and please keep us updated.
J
Jessica38821 Oct 2023 13:14Allthewayup schrieb:
According to which standard was the house built? In our house, everyone advised against a water-based fireplace from all sides. The combination of underfloor heating, heat pump, and water-based fireplace is considered "difficult to manage," and comments like "pearls before swine in a low-energy house" were made. Nevertheless, we pre-installed all the piping but are moving in first without the fireplace and will wait 2-3 years. We thought that going “all-in” from the start is harder to reverse than upgrading later. I wish you good luck finding the perfect setup and please keep us updated. We don’t follow a specific “standard.” The house was individually designed.
We have sand-lime brick plus 20cm (8 inches) of insulation and triple-glazed windows, if that’s what you mean?
J
Jessica38821 Oct 2023 13:18@RotorMotor Do you think this chimney connection works better, or the old version? With the old setup, we had the problem that the temperature in the buffer tank didn’t rise during winter, but it was almost unbearable in the living room. That’s why we wanted to make this change.
Jessica388 schrieb:
We have sand-lime bricks plus 20cm (8 inches) of insulation and triple-glazed windows, if that’s what you mean?What does the energy performance certificate say?Jessica388 schrieb:
Do you think the chimney connection looks better like this? Or the old version?The connection plan only shows the hot water system layout. That has no effect on room temperatures.Nevertheless, if the chimney cannot transfer the heat away, the room where it is located will of course become very warm. With the new connection layout, it can manage that and heats the domestic hot water.
J
Jessica38821 Oct 2023 13:32Mycraft schrieb:
What does the energy performance certificate say?
The connection diagram only shows the hot water system layout. It has no impact on the room temperatures.
Nevertheless, if the fireplace cannot dissipate the heat, the room where it is located will naturally become very warm. With the new connection layout, it manages to do so and heats the domestic hot water.We don’t have an energy performance certificate…Exactly, that was also our thought. That’s why we had it remodeled.
Jessica388 schrieb:
We don’t have an energy performance certificate…There still must be a calculation of the primary energy demand, etc., in the house documents.Similar topics