Surcharge for cooling function of air-water heat pump?

Hello,

we are now having a Vaillant Arotherm Split VWL 75/ with uniTower VWL 78/5 IS installed.

I have now read on the manufacturer's website that the aroTherm split can also be used for cooling with underfloor heating (which we have) if "proper design" is ensured.

Unfortunately, I haven't found any more information. What does "proper design" mean?

We will definitely ask our contact person about this at the next appointment. I just like to be prepared beforehand to know if it really causes additional costs or what exactly needs to be done.

With another home builder, we were once quoted a four-figure extra cost for the additional cooling function. But I don't remember which heating model was supposed to be installed then.

With us, it is about €3,500 for the cooling. This is probably mainly due to the thermostats, which simply cost much more.

Corresponding interpretation can mean anything. From the installation distances to additional components to the thermostats just mentioned. If the upgrade reaches the four-digit range, it is by no means justified and simply a rip-off and scam. The performance of cooling through the underfloor heating is only marginal. Assuming the house is occupied, this type of cooling is a battle against windmills.

I agree completely. We will invest the extra cost in a Mitsubishi split air conditioner with three indoor units. That way, it will at least be cool when needed.

Provided the house is inhabited, this type of cooling is a fight against windmills.

You certainly cannot generalize. Here with us, we have had very good experiences for the second summer now. Of course, the blinds on the south side are set to "slit," otherwise it doesn't work. But about 4 to 5 K less than outside still is inside the house. For us, it's very comfortable, and we don't want it any "colder" either. When you drive to Italy by car, you don't set the air conditioning to 18°C at 32°C outside in Austria, do you? It takes about 1000 kWh per season, and exactly when the photovoltaic system produces a lot. With the heat pump, it didn't cost us any extra (Rotex HPSU), and I have foregone special cooling thermostats. The actuators of the underfloor heating are just loosely hanging as decoration in the distribution box anyway...

But do you, for example, not find the cold tiles in the bathroom uncomfortable? Or does it not make a noticeable difference?