ᐅ New Single-Family House Construction (KFW70) / Aerated Concrete vs. Sand-Lime Brick / Which Material to Choose?

@Björn: I was referring to your explanation regarding the tolerance. That's exactly what I meant. For a gas condensing boiler, it doesn't really matter whether the flow temperature is 35 or 45 degrees Celsius (95 or 113 degrees Fahrenheit).

It should be like this: Björn did it (explained what I meant), you’re not supposed to be left in the dark.

Yes, and due to the much lower overall investment and interest costs, a gas condensing boiler would be positioned much lower on the chart... so the image is completely inaccurate.

The graphic only shows the operating costs. It has nothing to do with the initial investment costs! However, you would recover the additional costs of the brine heat pump after 20 years. The graphic demonstrates this (although with completely incorrect consumption values and therefore exaggerated differences). Of course, that is then just speculation. But that’s not something you usually do.

Perlenmann schrieb:
@€ That’s ridiculous. You don’t need to explain that to a layperson, do you?!...

Another answer was hardly to be expected, as it sufficiently demonstrates "expertise."

How many systems have you planned so far, and how many have you actually measured in operation?

@ Michalko:
The main goal of this chart isn’t to precisely reflect the price increases of heat pump electricity or gas; I have standardized it here, assuming a moderate 5% increase. No one knows how prices will actually develop in the future. It was only meant to show that they will certainly not decrease. Anyone who wants to use different values can recalculate based on their own assumptions.

@ Mycraft: "yes, and due to the much lower total investment and interest, a gas condensing boiler is also positioned much lower in the chart"
The investment costs shown represent only a rough estimate. In many cases, for example, gas condensing boilers plus connection costs are often at a similar level to an air source heat pump for the same heating load. With new construction, a gas condensing boiler still requires mandatory investment in a solar thermal system, which is completely avoided with a heat pump. It is not unreasonable that a ground source heat pump with vertical drilling usually costs more.

The chart’s sole purpose is to illustrate that there are significant differences, that careful planning is definitely worthwhile, and that over the life cycle, considerable consumption costs can arise.
It should be understood that additional costs, such as debt service, depreciation, maintenance, etc., exist and need to be considered in a comprehensive evaluation.
The majority of new buildings, at least in my planning experience, meet Energy Saving Ordinance (EnEV) standards or KfW 70, with KfW 55 being less common. Passive houses (PH) are rather the exception.

Best regards.

€uro schrieb:
Another response was not really to be expected, as it clearly shows "expertise."
How many systems have you designed so far, and how many have you measured in operation?

As I said, I am a layperson, so zero, none. But what does that have to do with anything? How much difference in percentage does increasing the flow temperature by 10 degrees Celsius (18°F) make on a gas condensing boiler? And how much on a heat pump? I don’t know the exact figures, but even as a layperson, I understand the general trend!
And if I am wrong (which I could live with), please enlighten me with a serious explanation! THAT would help everyone!

And please explain why you use 15 MWh/year as the basis?

Perlenmann schrieb:
...As I said, I’m an amateur, so zero, zero...

Exactly, that’s why you couldn’t answer my question.

Perlenmann schrieb:
...I don’t know the exact numbers, but as a layperson I recognize the trend!...

Gas condensing boilers and heat pumps are two completely different principles of heat generation. This leads to partly different requirements and necessities. Limiting the discussion solely to the flow temperature (VLT) is simply incorrect. Moreover, it is not the flow temperature itself, but precisely the temperature difference of the heating medium that is decisive. This is a very important factor for heat pumps but less so for gas condensing boilers. In fact, slightly higher flow temperatures can even be advantageous there!
Only the actual heat generator performance factor is a meaningful comparative criterion when it comes to energy balances.
For gas condensing boilers, this value is always > 1, since actual consumption is always greater than demand. For heat pumps, it is < 1, as consumption is lower than demand due to the use of environmental energy. For electric direct heating, it equals 1.
For gas condensing boilers, this value is determined by calculating the ratio of consumption recorded at the meter to the actual energy amount used for heating and domestic hot water (measured by a heat meter).

Perlenmann schrieb:
...And please explain why you use 15 MWh/year as the basis?

See my previous post. It is an average value from existing buildings and new constructions (Energy Saving Ordinance up to Passive House standard).

Best regards.