If the insulation is adequate, then gas with [Kontrollierte-Wohnraumlüftung] Low maintenance costs and low r consumption For me 176sqm, insulation according to passive standard 2 people 400€ gas per year
Better talk about your consumption in kWh. Besides, it’s not that cheap. I pay 4.5 cents gross per kWh. That would mean about 8900 kWh for you and an estimated heating load of 4-5 kW at [Norm AT]. With 4.5 cents plus the gas meter basic fee and a cheap €150 maintenance per year, you are already on par with a heat pump and an annual performance factor of 4.
No. You use gas with controlled residential ventilation and calculate whether that is sufficient. If it is sufficient, you do nothing further (unless you absolutely want to because you like photovoltaics or solar thermal).
What is the name of the calculation that needs to be done to see whether gas with controlled residential ventilation is already sufficient? Should the general contractor perform the calculation, or do I hire someone for that?
The general contractor, or rather their HVAC engineer, who always does this for them.
and also here: study. question. Could that be? Why? The proofs and calculations are not trivial, but logical and comprehensible with some effort. We once dealt with such an engineer (later canceled construction project). He could answer all questions with "I don't know exactly either, I have to enter it that way into the program.".... :-(
Thank you very much for your support! This is how I will proceed. If, in the end, solar thermal energy must be installed on the roof, it will only be as large as necessary to comply with the Energy Saving Ordinance. If such a small solar thermal system were used, would it be for supporting the heating, for hot water, or for both? Are there any recommendations?