ᐅ Which heating system is best for a new build without a mechanical ventilation system?

Alpandian89 schrieb:
What are the advantages of a ventilation system?

In short: Optimal indoor air quality (CO2, humidity, other odors, and microorganisms) can currently be ensured efficiently, permanently, and conveniently almost only through mechanical ventilation in modern buildings.

andimann schrieb:
If cost-effectiveness is important to you, I would consider a gas heating system.

That depends... With a creative energy consultant, the following should be evaluated:
- Gas heating with controlled ventilation (for energy regulations), but without solar thermal vs.
- Heat pump with controlled ventilation (for comfort)
Otherwise, gas plus solar thermal vs. heat pump without solar thermal. In our case, gas would have involved higher investment costs, and this will likely be the case in many other situations.

Alex85 schrieb:
With gas, solar, and controlled ventilation with heat recovery, you are pretty close to KfW55 standards.

I doubt that, well, depending on what "close" means.

Alex85 schrieb:

If the building components of the thermal envelope also meet the reference values, then the matter is settled. Or did I misunderstand that?

What we have implemented so far – if it has to be gas, it requires much more insulation. Otherwise, the energy saving regulation cannot be met with gas; achieving KFW 55 standard is even less feasible.

Overall, an air-to-water heat pump is more cost-effective, especially since it also avoids the expense of a gas connection.

Regards, Bauexperte

@Bauexperte
How should the reference value method be understood in this context? Is it then a kind of "loophole" to avoid completely banning gas in new buildings when no advantage can be gained using other calculation methods?

Alex85 schrieb:
@Bauexperte
How should the reference value method be understood then? Is it a "loophole" to avoid completely banning gas in new buildings when no advantage can be gained using other calculation methods?

I have long lost understanding for the people who come up with such nonsense.

The only undisputed fact is that gas is undesirable as a heat source in the medium term (and immediately in new buildings).

Regards, Bauexperte

Bauexperte schrieb:
The only undisputed fact is that gas is undesirable as a heat source in the medium term (and in the short term for new buildings).

...and it makes you independent from the Russians. *end of conspiracy theory*

For KFW55 certification, specific requirements regarding heat transmission loss and primary energy demand must be met. The heat transmission loss is entirely independent of the building systems. The primary energy demand is measured against a reference building, which uses gas heating.

Meeting the primary energy demand depends on the heat transmission loss. If the heat transmission loss is met just barely, then the building systems need to be 21.4% (1 minus (55 divided by 70)) more efficient than those in the reference building.

Since the KFW55 insulation is already quite good, most of the heat demand in the reference building is related to ventilation. If a controlled mechanical ventilation system is used there, achieving the 21.4% target is easily possible.