Oil tanks are out; air source heat pumps are in

Owing to his job at Swisshaus, the owner had already established an interest in heating technology as part of the energy transition. Now, he’s also taken this home with him. The oil heating system gave way to an external air source heat pump from CTA.

The family house and the pool are newly heated with a heat pump.

The old oil heating system in this house was worn out. The family home, conservatory and swimming pool are now predominantly heated with air as a renewable energy source. The heat pump also ensures there is a supply of hot water in the house. Choosing this sustainable solution didn’t just massively reduce the CO2 emissions – it also brought about efficient, low-maintenance and cost-effective heating.

Choosing the heat pump

This family home, dating back to the late 80s, has a lot of land around it. Although all variations would have been possible here, the owner opted for an external heat pump. An area behind the house, also close to the utility room, presented itself as the ideal place. Geothermal probe drilling would have made the pipe longer and more laborious to lay, as there was no room to place a drill point behind the house and on the slope. External heat pumps are quick to install and have lower investment costs when compared to other heat pump systems. Unlike internal air source heat pumps, external variations require planning permission from the municipality. The operating costs are a little higher than for geothermal probes or groundwater heat pumps: the colder the ambient air, the more energy the heat pump requires to bring the air temperature up to the heating temperature.

Martina und Toni Frei,building owners

A never-ending energy source

It’s so practical not having to think about ordering oil any more. This leaves us plenty of free time for our shared leisure activities. As an energy source for our heat pump heating system, air is always there.

The heat pump in use

The heat pump AH CM 18a is ideally suited to renovations as well as newly built family homes and apartment buildings. These heat pumps also offer sufficient heat output with good energy efficiency even when the outdoor temperatures are low. Depending on the required output, several units can be interconnected. The heat pump also runs quietly.


The heat pump in use

  • Highly efficient

  • Quiet operation

  • Cascadable/combinable

  • Silent Mode setting


The outdoor unit is placed behind the house.

Two types of air source heat pump

Air source heat pumps are installed on building exteriors or interiors. External units have a pipe that leads to the inside. Internal units require two air ducts: one to draw in the air, and another to release it back into the environment.

More about the heat pump types

In safe hands

Choosing a CTA heat pump means opting for a high-quality, durable product. Even though heat pumps are generally considered low-maintenance, regular servicing and checks are required to maintain their perfect and low-cost performance in the long run. For newly installed heat pumps, experts recommend taking out our “CTAplus” extended warranty. This comprehensive protection offers cover for up to 12 years from commissioning. Alternatively, or even after the “CTAplus” expires, we offer a flat-rate service contract that we, a family-run company with Swiss-based production, offer for all heat pumps.

More about the service


  • Installation: Affentranger Jakob Gmbh, Lengnau

  • Heat pump-supplier: CTA AG, Münsingen


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