ᐅ Underfloor heating with an air-to-water heat pump. House gets too warm when the sun is shining.
Created on: 4 Dec 2019 14:18
C
chewbacca123
Hello everyone,
I have a general question.
We moved into our new build four months ago. The living area on the ground floor has three large floor-to-ceiling windows facing south. We have underfloor heating and an air-to-water heat pump.
It provides a really comfortable temperature inside the house, but we have a problem – whenever the sun is shining in winter, even if it’s -2°C (28°F) outside, the temperature suddenly rises to 24°C (75°F) in the living room. It gets uncomfortably warm in here, and the underfloor heating can’t be turned down quickly.
Should we assume that the large floor-to-ceiling windows are responsible for the heat gain? A photo of the south-facing side of the house is attached.
What would you do – always lower all the blinds as soon as sunlight is forecast? That seems quite annoying...
We have motorized blinds controlled by Somfy. Would you consider buying a sensor that automatically lowers the blinds at a certain temperature?
Thanks in advance for your replies.
I have a general question.
We moved into our new build four months ago. The living area on the ground floor has three large floor-to-ceiling windows facing south. We have underfloor heating and an air-to-water heat pump.
It provides a really comfortable temperature inside the house, but we have a problem – whenever the sun is shining in winter, even if it’s -2°C (28°F) outside, the temperature suddenly rises to 24°C (75°F) in the living room. It gets uncomfortably warm in here, and the underfloor heating can’t be turned down quickly.
Should we assume that the large floor-to-ceiling windows are responsible for the heat gain? A photo of the south-facing side of the house is attached.
What would you do – always lower all the blinds as soon as sunlight is forecast? That seems quite annoying...
We have motorized blinds controlled by Somfy. Would you consider buying a sensor that automatically lowers the blinds at a certain temperature?
Thanks in advance for your replies.
Daniel-Sp schrieb:
How cold does it get for you?
Your heat pump can only modulate down to 5.4 kW at an outdoor temperature of 7°C (45°F) with a flow temperature of 35°C (95°F). At even lower flow temperatures, the minimum output is higher. I’m afraid the heat pump is oversized by about two steps. The LAV 8 would have been a better choice; it can modulate down to 2.8 kW at 7°C (45°F) outdoor temperature (with 35°C (95°F) flow temperature). Even that would likely be oversized considering the internal heat gains.
The high output at the lowest modulation level also explains the short running times per heating cycle. You mentioned this somewhere here in the forum. I see it the same way as you, but I can’t change it now. I should have insisted against the heating installer, who was determined to install the larger unit...
The circulation runs only very briefly during the day, a maximum of 1 hour.
M4rvin schrieb:
- Last 7 days 93 kWh
- Domestic hot water production continuously at 48°C (118°F)
- Circulation from 5:30 a.m. to 8 a.m. and 4 p.m. to 7 p.m.
- Heating curve slope 0.2 / offset +2°C (3.6°F)
- Set temperature 22°C (72°F) / actual room temperature 22.5°C - 23°C (72.5°F - 73.5°F)
- Heated area 130 m² (1400 ft²)
Previous setting:
Offset 0 and reduced flow (-20% pump speed)
Actual temperature 21°C (70°F)
Consumption week 15.01.-22.01. 89 kWh
Consumption week 08.01.-15.01. 108 kWh
Consumption week 01.01.-08.01. 103 kWh Hi!
One year has passed...
I consumed 2800 kWh and paid 560€ for the year.
When the heating was off, my consumption was 2.6–3.5 kWh/day.
In winter, it was 12–16 kWh/day.
I turned the heating on two weeks ago, but I have initially lowered the target temperature by 1 degree.
Hey,
does anyone happen to have a Rotex / Daikin HPSU Compact Ultra?
It would be great to see how the settings are supposed to be roughly. I’m still having some trouble with it. For example, right now the outdoor unit is “on.” Does it make sense for it to operate late at night when it’s cold outside?
Maybe someone can help—feel free to send me a private message to go through it together...
does anyone happen to have a Rotex / Daikin HPSU Compact Ultra?
It would be great to see how the settings are supposed to be roughly. I’m still having some trouble with it. For example, right now the outdoor unit is “on.” Does it make sense for it to operate late at night when it’s cold outside?
Maybe someone can help—feel free to send me a private message to go through it together...
I think he believes she should work during the day because the screed and similar materials can then efficiently store heat and draw from the stored warmth overnight. The heat pump control system would need to recognize that it gets colder outside at night and use the warmer air as a source. Whether this makes sense from a calculation standpoint, I’m not sure.
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