When is a heat pump really quiet enough?

Heat pumps are usually discussed in terms of efficiency, output and cost. In everyday life, though, another factor decides whether a system really works well: acoustics. Outdoor heat pumps in particular stand where people live — next to the house, in the garden, close to terraces or the neighbours' property. A modern heat pump therefore has to do more than heat reliably; it has to run so quietly that it hardly gets noticed. That is why low noise emissions are a consistent design goal for the ElephantONE.

Reducing noise where it is created

The main sources of noise in a heat pump are the fan and the compressor, and that is exactly where our acoustic concept starts. For the fan we use a noise-optimised design: adapted blade geometry, additional noise-reduction features and a larger fan. This lets the fan run at a lower speed — and reduces noise at its source. For the compressor we take a multi-stage approach: a low-vibration dual-rotor compressor, additional sound insulation and a sound-insulated housing for the heat pump system.

Quiet in operation — especially at night

Technical noise is perceived more strongly at night. That is why we are developing the ElephantONE with a silent-night mode that optimises operation acoustically during sensitive hours. The integrated system architecture helps: heat pump, storage, battery and controls work as one coordinated system, so heat can be generated and stored more flexibly — without unnecessarily loud operating points. Our development goal is clear: BEG-eligible from 2026, at least 10 dB below the ecodesign limit and night-time values compliant with TA Lärm (the German noise regulation) in typical installation set-ups.

Acoustics as a product principle — considered from the start

A heat pump is not good just because it is efficient. It also has to work where people live. That is why we do not treat acoustics as an add-on but as part of the product concept: noise is reduced directly at the fan and compressor, its spread is deliberately limited and operation is controlled intelligently. Because in everyday life, what counts is not only how efficiently a heat pump works, but also how unobtrusively it does so.