Page 28 - JCAU-7-3

Journal of Chinese
Architecture and Urbanism Natural ventilation in courtyard dwellings

and temperature profiles (Pathirana et al., 2019). Results to improving the accuracy of CFD simulations and to
indicated that stack ventilation was efficient, with warm designing energy-efficient, thermally comfortable indoor
air expelled through upper vents and cool air drawn in spaces.
through lower inlets. The presence of foliage within the Furthermore, CFD simulations and short-term
courtyard also contributed noticeably to daytime cooling measurement studies on courtyard dwellings in Inner
and improved thermal comfort (Figure 6).
Mongolia and Gansu revealed important seasonal patterns
To address the limitations of CFD-only approaches, in ventilation effectiveness. Air change rates and thermal
some researchers have begun using hybrid methods that comfort assessments showed that some occupied courtyard
combine CFD simulations with scaled wind tunnel testing residences remained uncomfortable due to inadequate
or real-time measurement data from occupied courtyard ventilation in corner rooms not directly exposed to
buildings. For instance, in the case of Gansu province, courtyard inlets. Additionally, user adaptation behaviors
hourly airflow and temperature data collected from sensor (e.g., temporary window sealing, the use of internal
arrays installed in an occupied residence were used to curtain barriers, and vegetation screens) were found to
calibrate simulation parameters. The comparison with significantly change airflow patterns compared to those
observed comfort conditions was improved through CFD predicted by simulation. These discrepancies, documented
calibration, thereby providing strong support for hybrid through thermal comfort logs and occupant diaries,
validation techniques. highlight the importance of incorporating behavioral data

In the CFD simulation study, efforts were directed into future design simulations.
toward assessing the effectiveness of three-dimensional 4.4. Climate-specific design considerations for Inner
steady-state RANS equations in modeling temperature Mongolia
stratification and indoor air quality in a displacement
ventilation environment. Utilizing full-scale measurement The results highlight specific design considerations
data, the shear stress transport k-ω turbulence model, related to the climatic features of Inner Mongolia, where
along with other associated modeling results on thermal hot summers and cold winters limit the consistent use of
stratification and airflow distribution, showed the best natural ventilation. While natural ventilation is primarily
agreement with empirical observations. The results used for cooling during the summer, it must be carefully
demonstrated that the model effectively captured managed in winter to avoid excessive heat loss (Chen
buoyancy-driven thermal plumes and recirculation zones, et al., 2020). Some studies suggest that courtyard geometry
with an average difference of 4.2% compared to measured should be adaptable to allow for seasonal alteration of stack
coefficients (Gilani et al., 2016). Sensitivity analysis ventilation strategies. For instance, in summer, courtyards
revealed that only grid resolution and the choice of should remain open to prevailing winds to enable effective
discretization schemes significantly affected overall results, cross-ventilation and cooling (Li & Chen, 2021). In
while the “age of air” predictions were largely insensitive contrast, during winter, courtyards should be partially
to iterative convergence criteria. These insights contribute open or buffered to prevent cold air infiltration and the

Figure 6. Comparison of temperature scale (T–Ti) from computational fluid dynamics simulation and experimental results. Source: Gilani et al., 2016.
Copyright © 2016 Building and Environment.

Volume 7 Issue 3 (2025) 10 https://doi.org/10.36922/jcau.7226