Choose air-water heat pump Viessmann or Alpha Innotec?

Dear Forum,

I kindly ask for your help with the following problem:

Initial situation: Single-family house with 180 sqm of living space, underfloor heating, no ventilation system, Kfw 70, air-to-water heat pump installed outside. According to the construction contract with the general contractor, the installation of an air-to-water heat pump Viessmann Vitocal 200 S is agreed upon. Now the builder informs us that instead of the contractually agreed Viessmann heat pump, a unit from the manufacturer Alpha Innotec Hydraulik Tower Dual LWD 70A/RX will be installed and refers to the following advantages: the outdoor unit is much quieter than the one from Viessmann, the indoor unit of the Hydraulik Tower requires only 0.5 sqm of space, and in case of malfunction, a special Viessmann installer does not need to be called.

We know Viessmann as a well-known manufacturer and, possibly due to lack of knowledge, have great concerns about deciding against the contractually agreed device.

How do the experts here in the forum see the two devices in direct comparison considering our above-mentioned conditions? Does anyone have personal experience with Alpha Innotec?

And the last important question: Does the general contractor possibly prefer the Alpha Innotec brand for cost reasons and because it yields a higher margin for him? If so, can the difference in acquisition costs be roughly estimated?

Many thanks for your help,
have a nice evening,

Ellen

Just compare the performance data.

In general, the potential (efficiency) problems later on are not with manufacturer A or B but with the sizing and installation of the heat pump.

You surely have solar thermal on the roof to achieve Kfw70 without a ventilation system?

I would worry more about that than about the heat pump manufacturer...

Hello everyone,

: sorry, I wasn’t aware that I had posted any link. I thought I had only copied the text. I will be more careful next time.

We have already looked at the cop. However, I have also often heard that relying solely on this value is too short-sighted. Also, it doesn’t help me if the datasheet looks good but the thing constantly fails.

We don’t have solar thermal on the roof. The hot water is provided by the heat pump.

As for the sizing, unfortunately I don’t know how to tell if it is correct. We don’t have a heating load calculation. Are we entitled to request this from the general contractor or do we have to rely on the calculation according to the KfW application or can something be read out of these?

Questions upon questions

Most likely, the change is not due to the margin but simply due to the workload of the [GÜ] and keeping the promised deadlines...

[GÜ] often work with several subcontractors, and the first plumber has Viessmann while the second has Alpha Innotec in their program. The one who gets your order from the [GÜ] installs their stuff.

That may well be the case, but we had the respective devices with the exact designation written into the house construction contract. In that respect, in my opinion, it is not so simple with "he just installs his stuff."

Don't get me wrong, I certainly don't want to insist on anything. I just currently lack the feeling whether I am supposed to have cheaper devices with lower quality installed for the sake of margin or if the systems are more or less equally good.

Ok then the situation is different...

But at first glance, the AI pump even seems to be more expensive... so it probably can't be due to the margin...