KfW 70 without ventilation system

Hello,

...I am quite capable of creating a heat demand calculation and ....

What does this heat demand calculation look like?

in this context also a cost/benefit analysis. Especially regarding the latter, heat recovery in single-family house KfW 70 is not a great advantage - measured by the energy saved in relation to the increased investment costs.

I never claimed that it is the "great advantage"! Rather the lesser evil.
The importance and influence of the climate location as well as user behavior on the energy balance seem to be unknown to you. How else would one come to such generalized pro and contra.

Best regards

Hello €uro,

I never claimed that it is the "solution"! Rather the lesser evil.

Unfortunately, it often reads differently in your replies here in the forum

The importance and influence of the climate location as well as user behavior on the energy balance seem to be unknown to you.

You might be surprised – no, it is not unknown to me. However, I am happy to be convinced of the practical opposite: in your opinion/experience, where does HRV, taking into account climate location and user behavior, play a meaningful role at all – for KfW 70 and below – in terms of cost-benefit ratio?

Kind regards

Hello,

..Unfortunately, it often reads differently in your answers here in the forum

I rather don't think so. It just seems that everyone only wants to understand what fits into their own portfolio.

... However, I am happy to be convinced by the practice-oriented opposite: ...

It is not my intention to convince, I only express my opinion/view, as the forum cannot replace professional advice but can only provide hints. What each individual makes of it is up to them.
It is not unusual that generalists do not conform here, and for me, it's actually not a big problem.

Best regards.

Hello,

we are also planning a house in solid construction, which according to the development plan must meet the KfW70 standard. Time and again, house construction companies try to convince us to install a ventilation system. We understand the economic interests of the companies.

However, we hope that with good insulation, a solar thermal system, and a large photovoltaic system (electricity generation) (southwest roof, approx. 40 sqm) enough "renewable" energy will be generated for KfW70. Does anyone have experience with this?!????

AGAINST the ventilation system speaks
- besides the well-known germ problem from air conditioning systems,
- and the 1 cm floating doors (which transmit every noise everywhere),
- above all the uniform climate zone that I would create in my house!
I definitely do not want that. I want to be able to have 24 degrees warm in the bathroom in winter and 17 degrees in the bedroom, 22 in the living room, and 15 degrees in the pantry!
Because I neither want to grill the supplies at 24 degrees nor freeze in the bathroom at 17 degrees!

The argument "Who is supposed to ventilate if no one is in the house?" seems strange to me. Where does all the moisture come from if no one is in the house?

The uniform climate zone finally convinced me against the ventilation system...

Has anyone perhaps already built a KFW70 house with gas condensing boiler, insulation, solar thermal, and photovoltaics (WITHOUT ventilation and WITHOUT pumps)?

Best regards

@DoaTJ:

I can understand your argument.
In principle, it must be clear that a super-insulated house requires certain rules to be followed.
In my opinion, the most important thing is proper execution to avoid condensation caused by thermal bridges.
Furthermore, it must of course be ensured that the moisture accumulating inside the house is regularly removed to the outside (through ventilation, of course).
Those who are aware of this can certainly do without the installation of a central ventilation system, which—as you have already mentioned—also brings some not insignificant disadvantages.

Regards

Hello, we also want to build a solid house. Bungalow; 150 sqm; attic not developed. We will get geothermal energy and NO ventilation system. The contract states that we are guaranteed a KfW 85 and the final heat determination will only take place after signing the contract. "But a KfW 70 is always possible!" according to the seller. Is that common practice? Can you get KfW 70 without ventilation with geothermal energy?