Wall Insulation Dominates Heating Savings in Cold-Region Factory Simulations

A modeling study of a large assembly workshop in Shenyang, a city in China’s severe cold region, has ranked the building-design levers that most strongly shape industrial heating and cooling demand. Using controlled simulations with the DeST software, researchers varied envelope insulation, window shading, and ventilation rates and tracked how annual thermal loads responded. Their central result is a clear hierarchy: walls matter far more than roofs, solar control cuts cooling but raises heating, and ventilation changes trade cooling savings against winter heating penalties.

The sharpest contrast appeared in insulation performance. Lowering the wall U value from 1.0 to 0.1 W/(m²K) reduced the modeled annual heating load by 10.6 percent. Applying the same U-value reduction to the roof produced only a 1.85 percent decrease. The authors identify wall insulation as the more influential measure, a finding that reflects the large wall area and heat-exchange exposure typical of tall industrial halls.

Window properties showed a two-sided effect. Reducing shading coefficients lowered cooling load, but it simultaneously increased heating load, because less solar gain entered the space during cold months. The study therefore concludes that thermal and daylight performance should be evaluated together rather than optimized for one season alone.

Ventilation rates produced a similar seasonal trade-off. Increasing outdoor air exchange reduced cooling load while raising winter heating demand, since more cold outdoor air must be warmed during the heating season. Boundary analysis in the study indicated that sensible heat recovery can moderate this penalty by transferring heat from exhaust air to incoming fresh air.

The simulations also identified a transition zone in the cooling response between 3 and 4 air changes per hour. According to the authors, this interval can inform ventilation design when it is combined with indoor air quality requirements and production needs, rather than treated as a standalone optimum.

Important limitations frame these findings. Because operational measurements and reliable production schedules were unavailable, the model was not calibrated against real building performance, and internal heat gains from equipment and processes remained fixed. The authors state that the results therefore represent comparative thermal responses to design parameters, not predictions of operational energy use for a specific running factory.

Within those constraints, the study establishes an ordered set of priorities for industrial buildings in severe cold regions: wall insulation first, followed by solar control, ventilation rate selection, and heat recovery. For designers of large workshops in climates like Shenyang’s, the practical message is that envelope decisions, especially on walls, carry disproportionate weight in the annual heating budget, while measures that help in summer can quietly cost energy in winter unless heat recovery is built in.

Subject of Research: Thermal load responses of a large industrial workshop to envelope insulation, window shading, and ventilation design in a severe cold region

Article Title: Thermal load responses of a large assembly workshop to envelope and ventilation design in a severe cold region

Article References: Chu, Q., Wang, H., Wang, J., Liu, H., Ming, Y., & Zhu, S. (2026). Thermal load responses of a large assembly workshop to envelope and ventilation design in a severe cold region. Scientific Reports. https://doi.org/10.1038/s41598-026-76870-6

Image Credits: AI Generated

DOI: 10.1038/s41598-026-76870-6

Keywords: building simulation, DeST, heating load, cooling load, wall insulation, U value, shading coefficient, ventilation rate, heat recovery, severe cold region, industrial buildings, Shenyang