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?
A
Alessandro19 Nov 2021 14:43Malz1902 schrieb:
Quick question: I lowered my heating curve from 0.16 to 0.1. Now the heat pump cycles 15 times in 24 hours at an outdoor temperature averaging 7°C (45°F).
With a heating curve of 0.16 and the same outdoor temperature, it cycled only 3-4 times. Which is better: a lower heating curve with more cycling, or a slightly higher heating curve with less cycling? 15 cycles at 7°C (45°F) outdoor temperature are perfectly fine! There’s no need to worry about that...
D
Daniel-Sp19 Nov 2021 17:22Alessandro schrieb:
15 times at 7°C (45°F) indoor temperature are absolutely fine! No need to worry about that...I see it differently...More explanation is needed
The system first needs to be properly adjusted, then you will automatically reach the "correct" number of starts.
The heating curve alone doesn’t say "squat." You need all relevant parameters.
Malz1902 schrieb:
I raised the heating curve from 0.2 to 0.24,
Malz1902 schrieb:🙄
Lowered the heating curve again, from 0.16 to 0.1.
The heating curve alone doesn’t say "squat." You need all relevant parameters.
driver55 schrieb:
The system first needs to be properly adjusted; then you automatically reach the "correct" number of starts.
🙄
The heating curve alone doesn't say anything at all. You need all the relevant parameters.Which ones do you need or would you like to have?I think that with a heating curve of 0.16 and only 3 cycles in 24 hours, it’s already well adjusted. Changing from 0.16 to 0.1 only changed the indoor temperature by 0.1 degrees.
Malz1902 schrieb:
The change from 0.16 to 0.1 caused the indoor temperature to change by 0.1 degreesAt what outdoor temperature? A change of 0.1 sounds really ambitious. I’m curious to hear your experience during the frost next week!
OWLer schrieb:
At what outside temperature? 0.1 sounds really ambitious. I’m looking forward to your experience report during the frost next week!At an average temperature over 24 hours currently at 5°C (41°F) and everything is fine, but I’m also curious about subzero temperatures.