I would like to revive the thread again, as we should decide this week which heating technology we will choose:
Is there any advantage to a complete indoor installation? We have a basement and enough space – so the only advantage of an indoor installation should be the appearance (no "ugly" outdoor unit) – right?
We are currently leaning towards 2 separate units, due to the already mentioned disadvantages of combined units. Since we also have enough space, for us the combined unit is only an advantage because of the slightly lower price. However, the advantages of 2 separate units outweigh this, which is why we tend to go for the split unit (i.e., outdoor installation).
Would you agree with that?
Regarding the ventilation system: Our general contractor said that with Tecalor, both sheet metal ducts and plastic ducts are installed (Viessmann apparently only installs plastic ducts now). Our heating installer will apparently basically install sheet metal ducts unless we "ask otherwise". What do you think about this? Should one tend to sheet metal rather than plastic? According to the general contractor, the plastic ducts cost about €1,000 more. The plastic ducts are apparently rounded – the sheet metal ducts are folded or square.
An enthalpy heat exchanger is included for us – are there any other important details that should be considered? Can you recommend a model from Tecalor here? Or are there "standard models"? I would like to be a bit more prepared before we have the conversation... the heating topic is important to me, but as a layperson it still feels somewhat "suspect".