Heat pump or gas with central ventilation system with heat recovery

Yes, it works, but not for every house and not with every energy consultant. The waste heat in the air is the renewable energy.

Just Google it, there are some people here and in other forums who have succeeded.

...Because this results in missing ventilation losses...

... which no longer make up more than 30% of the total heating effort. I would calculate everything and choose the cheapest option. In my opinion, gas and controlled residential ventilation are likely significantly more expensive than the simple air blower without extras.

The controlled residential ventilation system is not designed to save money. However, if it is planned, it can be used to dispense with [ST] in the case of gas heating.

So, now I am a bit further. I am interested in your opinion on the two topics:

1. Gas boiler: Vaillant ecoTEC plus / ventilation system: Multibreeze from Pedotherm and Vaillint Reco VAIR VAR 275

Vaillant is well-known and will certainly deliver good quality. Pedotherm is unfamiliar to me. Does anyone have experience here?

2. Enthalpy heat exchanger:

You wrote that I should definitely use it. However, it is not quite clear to me when it is useful for humidity recovery and what exact function it has. Can someone enlighten me and also share their opinion? The additional costs should be around 1,600 euros.

Many thanks

1. Multibreeze is, I believe, simply the term for the way Pedotherm builds the systems. "With the Multibreeze residential ventilation from PEDOTHERM your house receives controlled breathing. A supply air duct network installed in the floor continuously and draft-free supplies your rooms with fresh outside air." The actual ventilation is from Vaillant. Pedotherm does the underfloor heating and piping for the controlled residential ventilation for our general contractor. Everything worked well with them.

2. The problem is that with ventilation in winter it can quickly become very, very dry (25%), without the enthalpy heat exchanger the moisture goes straight out of the house. The heat exchanger extracts it from the exhaust air and returns it to the supply air. However, moisture must also be generated in the house by hanging laundry, showering, etc. For us, using the ET heat exchanger brought about 10-15% improvement and got us out of the unpleasant range. €1600 for the device is quite something. The original for our Tecalor heat pump should also cost €1500. We chose a retrofit solution and paid €700. Judging by pictures the same thing, just relabeled by the controlled residential ventilation manufacturer at double the price. The manufacturer is apparently Paul for all.