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ARTICLE

Performance Evaluation of the Hybrid Heat Pump to Decarbonize the Buildings Sector: Energetic, Environmental and Economic Characterization

Miriam Di Matteo^*, Domiziana Vespasiano, Gianluigi Lo Basso, Costanza Vittoria Fiorini, Andrea Vallati

Department of Electrical and Energy Engineering, Sapienza University of Rome, via Eudossiana 18, Rome, 00184, Italy

* Corresponding Author: Miriam Di Matteo. Email:

(This article belongs to the Special Issue: Selected Papers from the SDEWES 2024 Conference on Sustainable Development of Energy, Water and Environment Systems)

Energy Engineering 2026, 123(2), 1 https://doi.org/10.32604/ee.2025.064353

Received 13 February 2025; Accepted 05 December 2025; Issue published 27 January 2026

Abstract

Decarbonising the building sector, particularly residential heating, represents a critical challenge for achieving carbon-neutral energy systems. Efficient solutions must integrate both technological performance and renewable energy sources while considering operational constraints of existing systems. This study investigates a hybrid heating system combining a natural gas boiler (NGB) with an air-to-water heat pump (AWHP), evaluated through a combination of laboratory experiments and dynamic modelling. A prototype developed in the Electrical and Energy Engineering Laboratory enabled the characterization of both heat generators, the collection of experimental data, and the calibration of a MATLAB/Simulink model, including emissions and exhaust analyses. Sensitivity analyses were performed to identify optimal configurations for energy efficiency and system control, accounting for interactions between subsystems. Results highlight that hybridisation significantly improves primary energy efficiency and reduces fuel consumption compared to conventional NGB-only systems. Environmental performance, assessed through CO₂ and NOx emissions and renewable energy integration, demonstrates the benefits of partial electrification in the residential sector. Economic assessment further quantifies decarbonization costs and fuel savings, illustrating trade-offs between low-capital, moderate-performance systems and high-efficiency, high-renewable solutions requiring larger investments. The analysis shows that strategic decisions for residential decarbonisation cannot be separated from system-wide considerations, including control strategies, component integration, and economic feasibility. The study underlines the importance of hybrid and renewable-based solutions as pivotal pathways for energy transition in the residential building sector.

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