ᐅ New Construction: Can an Air Source Heat Pump Be Combined with a Photovoltaic System?

In our new construction planning, heating and domestic hot water will be provided by an air source heat pump from one of the following manufacturers: Viessmann, Brötje, Vaillant, Wöhler, or Novelan. Does anyone have experience with Brötje or any of the other companies mentioned, or can you recommend one of them?

We are also planning to install an additional photovoltaic system to complement the air source heat pump. Does anyone have tips or suggestions regarding this?

Thank you very much in advance.

We have a Vaillant Arotherm-Split air source heat pump with 3 kW.

The house itself is officially KFW 55 certified, but unofficially it’s closer to KFW 40. It has underfloor heating and a mechanical ventilation system with heat recovery.

Regarding the heat pump, I can’t say much at the moment except that the warm-up phase for the underfloor heating is coming to an end these days.

The electricity consumption was/is high as the warm-up phase was mostly powered by the electric heating element, and apparently it was only allowed to run that way.

The indoor unit is about the size of a refrigerator. The outdoor unit hums quietly, and you can occasionally hear a slight water dripping sound when it defrosts.

An 8.45 kWp photovoltaic system will be installed on the roof as soon as the weather permits.

We just received the provisional electricity bill from the energy supplier today: 150 € per month, which is partly due to the high electricity consumption during the current warm-up phase, especially since the photovoltaic system is not yet operational.

I would make sure that the heat pump is a modulating type, meaning it can adjust its output dynamically according to the current demand. I would no longer choose a fixed ON-OFF unit.

We have an LWAV 82R1/3 from Alpha Innotec and a photovoltaic system with 9.1 kWp on the roof.

Correct, a modulating heat pump works well with a photovoltaic system.

During the day, heat the water and underfloor heating at a higher level and use the screed as a heat and energy storage.

If you don’t need a heat pump with a cooling function (Halmi’s model has one), I can recommend the LWDV series from Alpha Innotec. Very efficient.

Otherwise, have a separate meter for the heat pump and household. Connect them in series within a so-called cascade metering setup. Both the household and the heat pump draw power from the photovoltaic system, allowing you to benefit from the lower electricity rates for the heat pump. This usually pays off despite a second basic fee!

@lesmue79 Why was the photovoltaic system not running during the screed heating program?

Because the photovoltaic system has not yet been installed. It was contracted externally and is not provided by the general contractor.

Ah, I missed that, it comes later, I understand. But you really should have checked that before the screed.