Parametric Analysis of a Dual-Fluid Air–Refrigerant BIPV/T Façade Concept

A solar-assisted heat pump (SAHP) with a building-integrated photovoltaic/thermal (BIPV/T) façade evaporator is presented. The novelty of the proposed configuration is the integration of refrigerant-based PV cooling and controlled cavity airflow within a single façade evaporator, such that the airflow provides an additional heat source under low-solar conditions. The air-side and refrigerant-side CFD models were independently validated against published experimental data before being combined for the parametric analysis. Under the investigated peak condition, the maximum predicted solar thermal and electrical efficiencies were 46.6% and 14.9%, respectively. Under off-peak conditions, the parametric analysis identified strong thermo-hydraulic sensitivity to flow ratio, tube height, and tube pitch. For the optimized system geometry, the proposed system has the potential to recover up to 50% of the peak incident solar energy reference during off-peak solar conditions. Further experimental work is required to validate the findings of the numerical study.