Hello everyone,
We have an 8 kW air-to-water heat pump from Kermi and a KfW55 house with about 200m² (2,150 sq ft). Currently, the indoor temperature is quite warm at 24.5°C (76°F). Yes, I know that is quite high. The consumption figures are only for the underfloor heating and are separate from the hot water usage.
I understand that the higher temperature leads to increased consumption, but could it possibly be too high?
We live just north of Hanau and in December maintained around 23°C (73°F) with a daily consumption of 6-8 kWh. When it got colder around Christmas, consumption rose to about 20 kWh. It has gotten even colder recently (-6 to 2°C / 21 to 36°F), and we simultaneously raised the temperature to about 24°C (75°F), resulting in a consumption of 30 kWh now.
I read that average consumption is based on 19°C (66°F), and for every degree above that, you need roughly 10% more energy. That would put us at about 60% higher consumption, but is 30 kWh then reasonable? According to the KfW application, we require around 30 W/m² (3 W/sq ft), which totals about 6 kW. But what exactly does that 6 kW refer to — over 24 hours? At what outside temperature? With an indoor temperature of 19°C (66°F)?
We had days in December with consumption as low as 6 kWh, which I think is quite good. However, with a few degrees colder weather and the heating curve increased by 1°C (2°F), the consumption jumps so much? By the way, we heat only via the heating curve, without any additional controllers.
Thanks in advance 🙂
We have an 8 kW air-to-water heat pump from Kermi and a KfW55 house with about 200m² (2,150 sq ft). Currently, the indoor temperature is quite warm at 24.5°C (76°F). Yes, I know that is quite high. The consumption figures are only for the underfloor heating and are separate from the hot water usage.
I understand that the higher temperature leads to increased consumption, but could it possibly be too high?
We live just north of Hanau and in December maintained around 23°C (73°F) with a daily consumption of 6-8 kWh. When it got colder around Christmas, consumption rose to about 20 kWh. It has gotten even colder recently (-6 to 2°C / 21 to 36°F), and we simultaneously raised the temperature to about 24°C (75°F), resulting in a consumption of 30 kWh now.
I read that average consumption is based on 19°C (66°F), and for every degree above that, you need roughly 10% more energy. That would put us at about 60% higher consumption, but is 30 kWh then reasonable? According to the KfW application, we require around 30 W/m² (3 W/sq ft), which totals about 6 kW. But what exactly does that 6 kW refer to — over 24 hours? At what outside temperature? With an indoor temperature of 19°C (66°F)?
We had days in December with consumption as low as 6 kWh, which I think is quite good. However, with a few degrees colder weather and the heating curve increased by 1°C (2°F), the consumption jumps so much? By the way, we heat only via the heating curve, without any additional controllers.
Thanks in advance 🙂
M. Gerd schrieb:
It is between 40-50%. Why?ypg schrieb:
Wow. Isn't that value quite high? How long have you been living in the house? There is a controlled ventilation system, so why is the humidity level so "high"?@ypg
Isn't that range considered the correct and healthy optimum!?
At least that has been my understanding so far, so your statement surprises me.
netuser schrieb:
@ypg
Isn't this range generally considered the correct and healthy optimum? At least, that's been my understanding so far, so your statement really surprises me.Absolutely correct. Below 40 percent is bad, and anything above 60 percent is not good either. The ideal would be 50 percent.Bookstar schrieb:
Absolutely correct. Below 40 percent is bad...At least from a health perspective, it’s "not ideal." So, roughly speaking, I would define the acceptable range as 35-55%. The optimal range is actually around 45-50%.
That’s exactly the dilemma nowadays: with controlled mechanical ventilation systems, the indoor humidity is often too low (below 35%) and the focus is more on increasing it rather than lowering it!
netuser schrieb:
At least from a health perspective, it’s “not ideal.” So, roughly speaking, I would consider the range of 35-55% as acceptable. The optimum, however, is around 45-50%.
Isn’t that exactly the dilemma nowadays, that with controlled mechanical ventilation the humidity is often too low (< 35%) and people rather try to increase it!?I agree. Even with enthalpy recovery, we currently only reach about 35%.HilfeHilfe schrieb:
Tenant who has not yet recorded consumption values. Water in the toilet was leaking slightly, but over more than 8 months it added up a lot. I think around 400 euros. OK, I thought water damage meant something else. But I never expected something like that to cost 400€. Wow.
Yes, currently we are at about 40%, sometimes slightly below. We don’t have the enthalpy data yet. We’ll have to see how the first winter goes, and if we add a few more plants, it might improve slightly. It’s something we are monitoring.
Otherwise, I’m waiting one more day regarding the current consumption values, but during the last 48 hours consumption was consistently about 20 kWh per 24 hours.
A
Alessandro19 Jan 2021 14:49Those are excellent values! 🙂