The four passive renovation strategies are opening, shading, inner facades, and underlying surfaces. They are evaluated by simulating each strategy on a Lingnan school courtyard prototype with ENVI-met and using the mean Physiologically Equivalent Temperature (mPET) of the courtyard observation area as the thermal comfort indicator. The simulations are run for the summer solstice period, and the results are compared qualitatively and quantitatively to identify the most effective renovation approach.

The study proposes four passive renovation strategies for improving thermal comfort in Lingnan school courtyards: opening (changing the position and size of openings), shading (adding vertical or horizontal shading), inner facades (changing wall materials), and underlying surfaces (changing surface materials and vegetation coverage). Each strategy is tested through controlled-variable simulations in ENVI-met using a representative prototype of a U-shaped courtyard with corridors, oriented north-south, with dimensions of 48 m × 28 m for the courtyard. The simulation period is the summer solstice (June 21) between 8:00 and 18:00, with meteorological conditions referenced from Shenzhen EPW data. Evaluation is based on the PET (Physiologically Equivalent Temperature) distribution and, more importantly, the mean PET (mPET) of the courtyard observation area, which serves as a comprehensive indicator of outdoor thermal comfort. Since summer PET in Lingnan often falls into the hot range, mPET is used to compare the thermal performance of the prototype against each renovation scheme. A detailed comparative analysis is carried out at 3:00 PM, when courtyard PET peaks, and partial correlation analyses are used to examine the relationships between renovation strategies, physical environmental factors, and thermal comfort. This combination of qualitative and quantitative analysis helps determine which renovation strategy offers the greatest thermal comfort improvement.

Key points

The four renovation strategies are opening, shading, inner facades, and underlying surfaces.
Each strategy includes design elements: opening has position and size; shading has vertical and horizontal options; inner facades concern wall materials; underlying surfaces relate to surface materials and vegetation coverage.
Evaluation uses ENVI-met performance simulation on a Lingnan school courtyard prototype.
The main evaluation metric is the mean Physiologically Equivalent Temperature (mPET) in the courtyard observation area.
Simulations are performed for the summer solstice from 8:00 to 18:00, with 3:00 PM selected for detailed analysis because PET peaks then.
Results are compared through qualitative and quantitative analyses, including partial correlation analysis, to identify optimal renovation strategies.

What are the four passive renovation strategies proposed for optimizing thermal comfort in Lingnan school courtyards, and how are they evaluated?