What are the recommended ranges for opening size, shading density, and grass coverage to optimize thermal comfort in courtyards?

The recommended ranges are: opening size from 1/4 to 3/4 of the courtyard's one-side length; west-facing vertical shading density from 0.25 to 0.50; horizontal shading covering 1/4 to 1/2 of the courtyard area; and grass coverage from 1/4 to 1/2 of the courtyard area.

These ranges come from performance simulations of renovated primary and secondary school courtyards in Shenzhen. For openings, positioning on the south or east side with a length spanning 1/4 to 3/4 of one courtyard side yields the best airflow and thermal comfort. For shading, west-facing vertical shading with a density of 0.25 to 0.50 effectively reduces afternoon solar radiation, while horizontal shading works best when covering 1/4 to 1/2 of the courtyard area. Increasing beyond these ranges reduces airflow and gives diminishing returns. For underlying surfaces, grass coverage of 1/4 to 1/2 of the courtyard area is recommended to balance solar radiation reduction with adequate airflow and daily usability.