Volume 58

A Multi-Objective Approach to Optimizing Sunspaces in Rural Dwellings for Energy Demand, Thermal Comfort, and Daylighting in Cold Regions of China Yuechen Duan, Yuanyuan Wei, Tao Zhang, Weijun Gao

Abstract

Rural dwellings in cold regions face the dual challenge of reducing energy consumption while maintaining thermal comfort and daylight. Although sunspaces are effective passive solar strategies, their optimization remains underexplored due to complex variable interactions and conflicting performance goals. This study proposes a multi-objective optimization framework to evaluate and enhance sunspace design in cold-climate rural buildings. Four comparative scenarios are established to decouple sunspace effects from baseline building performance: (1) unoptimized building, (2) optimized building, (3) unoptimized building with sunspace, and (4) optimized building with sunspace. Optimization integrates a genetic algorithm with EnergyPlus and Radiance simulations, targeting total energy demand (EDtot), thermal comfort (PNTave), and daylighting (UDIave). Sensitivity analysis highlights key variables such as window-to-wall ratio and solar heat gain coefficient (SHGC). A two-stage assessment compares cost-free and cost-constrained scenarios. Results show that combining an optimized envelope with a sunspace achieves the best outcome, reducing EDtot by 89.82% and raising PNTave to 77.66%. Optimizing the envelope alone reduces EDtot by 62.41% with a 1.91-year payback, while a cost-constrained sunspace alone provides limited improvement (14.85% EDtot reduction). This structured approach isolates the impact of sunspaces and offers practical guidance for cost-effective retrofits of rural housing in cold regions.

Keywords Sunspace, rural dwellings, cold climate, multi-objective optimization, energy systems, passive solar design