Air-to-water heat pump: choice between Viessmann and Ochsner

Hello dear community,

we have two air-to-water heat pumps offered for our semi-detached house:
1. Viessmann Vitocal 200-S 201.E10 with 7.4 kW
2. Ochsner Air Hawk 208 C11A

Important is above all trouble-free operation, reasonable service.

Key data about the house:

[*]Semi-detached house, will be built solid, not a KfW house (so about "KfW-60")
[*]Two full floors + basement, ground floor + upper floor 68 + 68 sqm, plus about 30 sqm heated basement part
[*]Underfloor heating, controlled ventilation system (controlled living space ventilation) with heat recovery and enthalpy heat exchanger
[*]No photovoltaic system primarily

Do you have experience with both? I could only find rather negative reports about the Vitocal.
The installation company mainly works with Viessmann systems and explicitly recommends it, but can also install the one from Ochsner.

Thank you!
Best regards

we have two air-to-water heat pumps offered for our semi-detached house: 1. Vitocal 200-S 201.E10 with 7.4 kW 2. Ochsner Air Hawk 208 C11A

Are you trying to say that you seriously have T.W.O. options for the delivery of a heat pump "in times like these"? - I constantly hear from people who have to wait for the household usual quantity "1 piece" until "who knows when"...

Viessmann is already out, as it is clearly oversized. Then, not much is left.

Are you trying to say that you seriously have T.W.O. options for the delivery of a heat pump "in times like these"? - I constantly hear from people who have to wait for the household usual quantity "1 piece" until "nobody knows when"...

That’s what the construction company or installation company says. Construction start 3rd quarter, installation 2024

Viessmann is already out, as it is clearly too oversized. Then there is not much left.

The heating load calculation is still pending, but - roughly estimated: the new building according to the Energy Saving Ordinance 2016, a heating demand rather towards 0.05 kW/sqm, approximately 165 sqm of heating area: 0.05 x 165 = 8.25 kW. The pump from Viessmann has 7.4 kW. Why is it considered too oversized? Just for understanding :)

That is what it is called by the construction company or installation company. Construction start 3rd quarter, installation 2024

That means they are basically betting that the supply bottlenecks will be resolved by then (?)