From Internal Sources to Urban Immission: Approaches to Understand Noise Propagation within Outdoor Heat Pumps and in Residential Areas
The sound of a heat pump, as perceived by owners and neighbors, results from an interaction between various internal sources (including the compressor, the cooling circuit flow, the ventilator fan, and electronics) and the transfer paths connecting these sources with the recipients. This paper presents the methods and findings of a research project that examines noise propagation from heat pumps from different levels of detail. In particular, the in-situ characterization of the compressor’s blocked forces is described, alongside an analysis of how the placement and installation of heat pumps in residential settings alter perceived noise. Laboratory experiments, field measurements, and digital simulations, using sound power data and typical urban configuration models, demonstrate that measures such as optimized location, noise barriers, soundproof enclosures, and soundabsorbing facades can significantly reduce noise emissions. The study concludes with recommendations to improve the integration of noise mitigation strategies into urban planning.