Air-water heat pump + controlled residential ventilation - (central ventilation system)

Good day everyone,

brief key data from our side:

- KFW 55 single-family house with 160m² and basement
- 2 full floors with hipped roof
- currently 2 people – hopefully 4 people in a few years

we are shortly before signing the contract – but unfortunately we are still very uncertain about one topic, as we have received very little input in this area.

It concerns the models/connection of our air-water heat pump and the controlled residential ventilation (central ventilation system):

The following was offered by our general contractor:

Option 1:

- Compact unit – controlled residential ventilation + air-water heat pump in one --> Brand/Model: Tecalor THZ 504 SOL
--> Includes the air-water heat pump which is included in our house price --> additional costs of €8,000 (for the controlled residential ventilation) would still be added if we decide on this device.

Option 2:

- Air-water heat pump with outdoor installation + central ventilation system as a separate device --> Brand/Model air-water heat pump: Tecalor TTL 7.6 ACS
--> Includes the air-water heat pump which is included in our house price --> additional costs of €12,000 (for the controlled residential ventilation) would still be added --> Here we are apparently "free" in the model selection of the controlled residential ventilation – we would have to see what the trade offers us.

Option 3:

- Air-water heat pump with indoor installation + central ventilation system as a separate device --> Brand/Model air-water heat pump: Tecalor TTL 9.5 I
--> Includes the air-water heat pump which is included in our house price --> additional costs of €12,000 (for the controlled residential ventilation) would still be added --> Here we are apparently "free" in the model selection of the controlled residential ventilation – we would have to see what the trade offers us.

Has anyone had experiences in general regarding the difference between indoor installation/outdoor installation? Which is better? We get both models at the same price. Both should reach the annual performance factor of 4.5 and are eligible for BAFA funding. Does anyone have experience possibly with exactly these devices? Is €12,000 a reasonable amount for the controlled residential ventilation? Will I get something good for that? Are there model/manufacturer recommendations for this as well?

There is also the question:
--> Is such a "compact unit" actually any good? Does anyone know this device? Is that the "future"? Of course, we could effectively save €4,000 this way.

Would never go for a compact device, it actually only has disadvantages.

Would never go for a compact device, it actually only has disadvantages.

Mine works. Tecalor thz 504. To each their own.

Yes, but a controlled residential ventilation system, if it is defective, would simply be replaced... if it is integrated in the heating system, it will probably be more expensive.

Yes, but a controlled residential ventilation system, if it is defective, would simply be replaced ... if it is integrated into the heating system, it will probably be more expensive

That is the question I am also asking myself.

Only: Where do you get this thesis from? Is that really the case? Is the repair effort higher for a compact unit? If the controlled residential ventilation system is defective, can't I buy a separate ventilation system anymore? Do I always have to stick to a compact unit then?

Would never go for a compact unit, it actually only has disadvantages.

Because you write that a compact unit "only" has disadvantages: Can you also name other disadvantages here?

I find the input in these areas here in the house building forum very meager. Is it because the expert knowledge required is really extremely high, or that as a builder you don't really need to or shouldn't know about it? Is there more "trust" in the trade/general contractor in this area? Do you just have whatever the general contractor suggests installed here?

I would like to know that because the topic concerns me a lot and I actually have a very hard time deciding...

Compact devices have poorer repair properties. Also often compromises, because everything has to fit into a tight installation space. I also think it is more difficult if you want to replace one of these devices.