ᐅ Air-to-Water Heat Pump: Current Consumption and Data

Alessandro schrieb:

But what’s the point of working with ERR to save energy if I still have to operate at 40°C (104°F) supply temperature to heat the house?

Have you tried fully opening all the ERRs and lowering the heating curve?

Bookstar schrieb:

That contradicts all physics and heating technology. Higher supply temperatures significantly increase consumption, especially with a heat pump.

Maybe I’m thinking about it wrong because my heat pump is return-temperature controlled. The supply temperature is reached relatively quickly. From a consumption perspective, the jump from a supply temperature of 30°C (86°F) to 33°C (91°F) takes about 15 minutes. When dealing with 2 kWh, that’s negligible. What takes longer, of course, is reaching the target return temperature.

But that only happens once because the temperature level then adjusts relative to the return temperature.

The hydraulics of an underfloor heating system are not simple; sometimes minimal adjustments can have significant effects. I am currently throttling the circuits, and yesterday a slight reduction in one circuit caused the entire heat distribution to become unbalanced.

Daniel-Sp schrieb:

Of course, the supply temperature also affects the efficiency, which can be seen in the performance charts of heat pumps. These are usually specified for 35°C (95°F) and 55°C (131°F) heating water temperatures. And indeed, the COP is lower at the same air temperature when the heating water is 55°C (131°F) compared to 35°C (95°F).
What type of heat pump does @Zaba12 have? Modulating or fixed-speed?

Fixed

Are you able to track the heat demand over a longer period? For my home, I get about 18,000 kWh per year including hot water. From the energy performance certificate, I read 25 kWh/m² plus hot water. When I calculate it that way, I get around 10,000 kWh per year. Of course, that’s an idealized calculation method. They also assume a dry building, etc. But my actual consumption is 80% higher. That surprises me.

I have already explained what information is needed to comment on this. Without providing data, it is not possible to say anything.

Bookstar schrieb:

Can you actually read out the heat demand over a longer period? For my place, it comes to 18,000 kWh per year including hot water. From the energy certificate, I see 25 kWh/m² (8 kBtu/ft²) plus hot water. When I calculate it that way, I come to about 10,000 kWh per year. Certainly, that is an idealized calculation. They also assume a dry building, etc. But I am 80% above that, which surprises me.

The data from the energy certificate are worthless; they only reflect the actual consumption inadequately. For example, the quality of the floor heating design is not considered at all in the energy certificate.