Which heating concept for new construction without ventilation system?

Hello Alpandian89,

I would add the mentioned points with your personal user behavior. It would certainly be interesting to question your hot water consumption, for example. The higher the proportion of hot water to be generated, the more the efficiency of the heat pump decreases, which then favors the targeted gas condensing boiler solution with solar thermal support; the roof orientation should also be relatively suitable for this.

I would definitely support the point about the ventilation system. Both for energetic reasons (heat recovery) and hygienic reasons (air quality, air exchange), this is especially attractive in new buildings due to the relatively low costs.

Best regards, Erik

I would add the mentioned points with your personal user behavior. It would certainly be interesting to question, for example, what your hot water consumption is? The higher the proportion of hot water to be generated, the more the efficiency of the heat pump drops, which then plays into the hands of the targeted gas condensing boiler solution with solar thermal support; the roof orientation should be relatively well suited for this.

Depending on the heat pump, the annual performance factor for hot water operation is even better. For example, some devices from ROTEX, which provide water via hygiene storage tanks and therefore only need to heat to 45 degrees. In this case, the more hot water, the better the annual performance factor. But in general, the differences are marginal. You also cannot cool with a natural gas heating system, and eventually you will be forced to switch (in 10, 20, 30 years) because fossil fuels are politically no longer desired.

To achieve KFW55 according to the Energy Saving Ordinance 2016, the following parameters must be met:

Roof surfaces, top floor ceiling, dormers U ≤ 0.14 W
Windows U ≤ 0.9 W
Masonry U ≤ 0.2 W (hardly achievable with unfilled Poroton at normal thickness)
Entrance door U ≤ 1.2 W

If gas is used, you need controlled residential ventilation and solar:

Condensing boiler, solar domestic hot water preparation (standard values according to DIN V 4701-10), central ventilation system with heat recovery (heat supply rate > 80%)