How a heat pump can even fit under a window—and make an older building in Bochum energy-efficient for the future.
In a quiet residential neighborhood in Bochum in Germany a typical post-war house built in 1955 can be found – unspectacular from the outside, but a prime example of modern energy technology on the inside. Jasmin and David Eichholtz live here with their three children Leo, Tom, and little Hannah. The building used to be heated by a gas boiler. Today, a Vaillant aroTHERM plus heat pump provides efficient and thus cost-effective heating. Due to the small safety distances, installing the new aroTHERM plus was no problem even with limited space. In front of the house, the heat pump in its elegant black-gray design cuts a fine figure – and cannot be heard by the neighbors even when operating at full capacity.
It was clear to us that if we were going to modernize, we would do so with a view to the next 20 years
The system architect, who works for Vaillant, planned the entire installation himself. The realization was carried out by Alexander Lipps from Ueckermann & Lipps, a craftsmen’s business with 95 years of history that now specializes in modern system solutions.
“We had previously installed a Vaillant heat pump at Ms. Eichholtz's parents' house—two streets away. Based on their positive experience with us, the Eichholtz family then commissioned us again,” says Lipps. The decision in favor of the aroTHERM plus was made because of its performance, its flexibility of installation, and its low noise emissions—as well as its elegant black-gray design.
The Eichholtz family has extensively modernized their single-family home: insulation of the exterior facade, new windows, refurbishment of the attic, installation of a PV system with battery storage. Nevertheless, installing the heat pump was no easy task: “We had exactly one suitable location—right next to the house wall under a window,” says David Eichholtz. “This would have been difficult with a conventional heat pump – the new Vaillant aroTHERM plus allows for significantly smaller distances owing to its innovative safety concept.”
The system was installed in less than five days – including the foundation and electrical work. The indoor unit was fitted in the space previously occupied by the gas boiler. The Eichholtz family deliberately decided against a buffer storage system in order to save space and increase efficiency. Heat is distributed via a single heating circuit that supplies underfloor heating and flat radiators. Due to the environmentally friendly R290 refrigerant, the Vaillant aroTHERM plus can also heat existing buildings very efficiently.
A real highlight is the system integration with the SolarEdge PV unit. The heat pump communicates fully automatically with the inverter and battery storage—the entire system is integrated into an intelligent energy management system. “In the past, smart homes were all about convenience – today, they are also about cost control and maximizing self-consumption,” says Lipps. “Those who generate electricity also want to use as much of it as possible themselves – for heating, cooling, hot water, or charging electric cars, for example. The SolarEdge PV system in combination with the Vaillant aroTHERM plus is perfectly suited for this.”
Another bonus: the option of cooling—gently and efficiently via the underfloor heating system. “Even when it's 30 degrees Celsius outside, we have a comfortable 23 degrees upstairs,” says Jasmin Eichholtz. “Without any additional appliances, just using the heat pump. The indoor climate is noticeably better than it used to be.”
Due to its low safety distances, the aroTHERM plus can be installed flexibly—even in places where conventional heat pumps cannot be technically fitted.
Alexander Lipps makes final adjustments to the sensoCOMFORT system controller, which enables convenient control of the heating system via an app and, among other things, flexible integration of photovoltaics.
Fully integrated into the energy management system – installer Alexander Lipps and homeowner David Eichholtz can monitor all operating data for the new aroTERM plus at any time via an app on a tablet or smartphone.
We wanted to become independent of gas and help protect the climate – and that’s exactly what we have accomplished.
The aroTHERM plus heat pump was the right choice. Efficient, quiet, visually appealing – and perfectly interconnected with the PV system.
Single-family home, semi-detached house
Built in 1955, extension added in 2006
Energy-efficient renovation of the attic + PV system: 2023
Living space: approx. 300 m² (of which 240 m² is heated)
Air/water heat pump: aroTHERM plus 10 kW
Hot water tank: Vaillant uniSTOR VIH RW 250
Control system: Vaillant sensoCOMFORT VRC 720
Heat distribution: One heating circuit (without buffer tank / without hydraulic separator)
Heating surfaces: Primarily underfloor heating + individual flat radiators
Project duration for heat pump: approx. 5 days of work
PV system: 12.4 kWp
Battery storage: 12 kWh
PV system manufacturer: SolarEdge
Energy management: Full integration of the heat pump into the SolarEdge system
