Just out of curiosity, to better understand the slope of the heating curve, what flow temperatures do you typically run at 0°C (32°F) outdoor temperature, given a certain indoor temperature and insulation level, when using a combination of underfloor heating and a heat pump?
Background of the question:
My logic tells me that if I want, for example, 22°C (72°F) room temperature, the flow temperature must be at least 22°C (72°F) or higher, since I learned that there needs to be a temperature difference for heat transfer to occur.
So if my heating system turns on at 12°C (54°F) outdoor temperature, my flow temperature should logically start somewhere around 22°C–25°C (72°F–77°F). Accordingly, at only 5°C (41°F) outside, it should be around 27°C (81°F), and at 0°C (32°F) close to 30°C (86°F).
The system design usually takes the location and outdoor temperature down to about –12°C (10°F). If at 0°C (32°F) flow temperature is already 30°C (86°F) according to my logic, then at –12°C (10°F) the flow temperature should be about 40°C (104°F). But most underfloor heating designs for heat pumps are based on a maximum flow temperature of 35°C (95°F).
Of course, the insulation of the house and the indoor temperatures still play a role. Or is the increase in flow temperature actually so gradual that it only rises by about 0.5–1°C (1–2°F) for outdoor temperature drops in 0–5°C (0–9°F) increments?
Background of the question:
My logic tells me that if I want, for example, 22°C (72°F) room temperature, the flow temperature must be at least 22°C (72°F) or higher, since I learned that there needs to be a temperature difference for heat transfer to occur.
So if my heating system turns on at 12°C (54°F) outdoor temperature, my flow temperature should logically start somewhere around 22°C–25°C (72°F–77°F). Accordingly, at only 5°C (41°F) outside, it should be around 27°C (81°F), and at 0°C (32°F) close to 30°C (86°F).
The system design usually takes the location and outdoor temperature down to about –12°C (10°F). If at 0°C (32°F) flow temperature is already 30°C (86°F) according to my logic, then at –12°C (10°F) the flow temperature should be about 40°C (104°F). But most underfloor heating designs for heat pumps are based on a maximum flow temperature of 35°C (95°F).
Of course, the insulation of the house and the indoor temperatures still play a role. Or is the increase in flow temperature actually so gradual that it only rises by about 0.5–1°C (1–2°F) for outdoor temperature drops in 0–5°C (0–9°F) increments?
This morning, the temperature was consistently between 20.5°C and 21°C (69°F to 70°F), but this is not very meaningful since it was too warm yesterday and the heating only turned on in the evening (shut-off temperature set at 12°C (54°F)).
A heating curve of 0.1 is definitely a bit low, considering the maximum of 30°C (86°F) at around -11 to -12°C (12°F to 10°F). It’s more likely that a 0.15 curve would be appropriate.
A heating curve of 0.1 is definitely a bit low, considering the maximum of 30°C (86°F) at around -11 to -12°C (12°F to 10°F). It’s more likely that a 0.15 curve would be appropriate.
I envy you. I have to reduce the flow rates of all circuits except for the bathroom and guest toilet; otherwise, these two rooms don’t get properly warm, and all the other rooms become too hot. If I lower the heating curve, these two rooms won’t get warm enough even with full flow.
Malz1902 schrieb:
I need to reduce the flow to all the loops except for the bathroom and guest toilet; otherwise, these two rooms do not really get warm.It is normal for the bathroom to have the highest flow rate, and as long as the heat pump is allowed to handle the required volume flow, this is not an issue. 2.5 and the rest each at 0.3 would, of course, be suboptimal.Bathroom and guest WC 3 l/min (0.8 gal/min) Children’s room and office each 1 l/min (0.26 gal/min) Living room with 3 heating circuits each 0.7 l/min (0.18 gal/min) and kitchen with 2 heating circuits each 1 l/min (0.26 gal/min) Hallway ground floor and hallway upper floor each 1 l/min (0.26 gal/min) Dressing room and bedroom 0.3 l/min (0.08 gal/min)
Malz1902 schrieb:
By the way, the heating curve is set at 0.3 and the spread at 1The "cabin" is from 2017, so 0.3 is obviously way too high. And where is the target room temperature?Flow/return temperature difference 1 K (1.8°F)? 🙄
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