Increasing market transparency of residential air-to-water heat pumps in Europe by clustering the appliances
The transition to low-carbon heating requires not only efficient technologies but also transparent markets that enable informed policy and consumer decisions. Yet, users and installers face challenges in comparing air-towater heat pumps (AWHPs) due to complex technical parameters and inconsistent model naming across countries and online platforms. This study aims at helping to navigate in choosing the heat pump by improving the understanding of how heat pumps are priced in Western Europe. Using the open-source hplib library, a dataset of 696 Keymark-certified AWHPs from 13 manufacturers was compiled, covering units up to 13 kW using low-GWP refrigerants R32 and R290. Retail prices were collected through automated web scraping of European online vendors and matched to certified technical parameters. Price modelling shows that the main price drivers are rated power, storage size and refrigerant type. Together with noise emission, standby power, reference COP (coefficient of performance), and tank configuration, these factors explain most of the observed price variation (R² = 0.84). The three dominant drivers substantially outweigh the influence of COP, which contributes only marginally to price formation. Unsupervised clustering identified five distinct product groups differentiated mainly by brand origin (EU vs. non-EU) and configuration (monoblock vs. split). European heat pumps show higher maximum supply temperatures and lower noise levels, indicating premium and suitability for retrofits, while non-EU heat pumps focusing on affordability. The efficiency remains similar between regional groups (SCOP = 4.70 EU vs. 4.76 non-EU). However, European models are priced higher (€1,362/kW vs. €1,023/kW). Overall, this study integrates model matching, price modeling, and clustering to contribute to a transparent, data-driven European AWHP market. The findings enhance product comparability and provide evidence to support policymakers and consumers in accelerating the heat-pump transition.