Multi-Performance Enhancement of Guanzhong Rural Dwellings: A Case Study on Parametric Effects of OSRW System

Improving the thermal, daylighting, and energy performance of rural dwellings in cold regions is important for low-carbon rural construction. This study evaluated a composite on-top sunspace roof window (OSRW) for narrow-deep Guanzhong rural dwellings in Shaanxi Province, China. A field-informed benchmark model, supported by field surveys and short-term hygrothermal measurements, was simulated using an EnergyPlus–Radiance framework within Rhino–Grasshopper. Performance was assessed using useful daylight illuminance (UDI100–2000), PMV-based annual comfort hours, and annual total load. Single-variable parametric simulations, feasibility-band screening, and a combined-variable consistency check were used to identify practical design ranges. The recommended configuration included a side roof WRR of 0.7–0.8, central roof WRR of 0.5–0.7, OSRW cavity height of 0.4–0.8 m, story height of 3.2–3.6 m, south facade WWR of 0.3, and R-type inner-window configuration. In the combined-variable check, annual load reductions remained positive across all retained cases (10.97–65.37%), UDI generally improved (mean 4.46%), and thermal comfort showed clearer trade-offs (−9.58–6.70%), mainly controlled by side roof WRR. These findings provide construction-oriented OSRW parameter guidance for similar narrow-deep Guanzhong rural dwellings under comparable benchmark, weather, and operational-control assumptions.