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?
Since we never wear slippers or similar indoor footwear, you can clearly feel the difference between a tile temperature of 20°C (68°F) and 24°C (75°F).
It might not bother me much, but my wife notices every single degree when I adjust the heating.
I once set it to a 5°C (41°F) parallel shift instead of 6°C (43°F), and she noticed immediately.
It might not bother me much, but my wife notices every single degree when I adjust the heating.
I once set it to a 5°C (41°F) parallel shift instead of 6°C (43°F), and she noticed immediately.
Musketier schrieb:
Unfortunately, there is no intermediate step between a slope of 0.2 and 0.3. Correction
I actually meant between 0.1 and 0.2.
Has anyone here ever observed the behavior of the systems and the corresponding room temperatures over a longer period of time? These snapshots don’t provide any meaningful information. The supply temperature constantly fluctuates. This means that it can have completely different values in the same house, even with the same outdoor and indoor temperatures.
S
Strahleman23 Dec 2021 01:59Mycraft schrieb:
These snapshots don’t really tell us much. But they do make it easier to compare heat pump and underfloor heating sizing 😉 By the way, I think mine is probably not the shortest...
Room temperatures are all around 21.5 - 22 °C (70.7 - 71.6 °F).
Strahleman schrieb:
But they make it easier to compare cock sizes when it comes to heat pump and underfloor heating design. Not really, because these are just snapshots. Only when you have the complete picture can you actually draw any conclusions. You can show these snapshots alongside the particularly good values here, but when the heat pump struggles, that part simply won’t be shown.
B
Benutzer20023 Dec 2021 09:57Mycraft schrieb:
Not at all, because these are just snapshots in time. You can only draw conclusions when you consider the entire picture. You could present these snapshots alongside the particularly good values here, but when the heat pump struggles, that simply isn’t shown. I can tell you that my heat pump consistently operates with a supply temperature of 29/30°C (84/86°F) from -4°C to +4/5°C (25/41/41/41°F). The room temperature remains constant. However, the power consumption varies due to different compressor frequencies and varying flow rates.
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