Abstract This study presents a numerical analysis of an indirect-expansion water-to-air heat pump (HP) combined in series with linear concentrating photovoltaic thermal collectors (CPVT), to meet the space heating demand of a residential house during the cold season, while maximizing the solar contribution. The system is dynamically simulated in TRNSYS under real climatic conditions in Constantine, Algeria, based on the actual thermal load of a modeled house. The CPVT collector field and the thermal storage volume are sized to optimize solar coverage and limit thermal losses. The results show an optimal thermal efficiency of the collectors throughout the heating season, with an average of 47% during sunlit hours. However, the concentration of solar radiation affects the electrical efficiency, which averages 6.29% during these hours. The CPVT collectors supply 58% of the heat pumps thermal demand, with coverage ranging from 34% to 83%, while the heat pump meets 93% of the total heating demand with an average COP of 4.8, demonstrating the relevance of the CPVT-HP system. A sensitivity analysis indicates that thermal efficiency increases with ambient temperature, whereas electrical efficiency slightly decreases with higher irradiation. The economic analysis, conducted under two operating scenarios, reveals that in the most favorable scenario, energy savings reach 8000 USD with an estimated payback period of 9 years, confirming the system's profitability when operated year-round. Overall, the results highlight the technical, economic, and environmental viability of this CPVT-HP coupling, particularly in regions with high solar potential.
Ayat et al. (2026) studied this question.