Evaluating urban outdoor thermal comfort: a validation of ENVI-met simulation through field measurement

Abstract

Thermal comfort plays a significant role in encouraging people to utilize outdoor spaces. Therefore, this feature must be analyzed and evaluated in order to be improvised. Computational fluid dynamics (CFD) is an alternative technique that predicts thermal comfort and environmental parameters. Validation of CFD is important to ensure its effectiveness. This study assessed the performance of ENVI-met for its ability to estimate thermal indices (PET) by comparing it to field measurement for various points in a street canyon in Port Said, Egypt, throughout the summer and winter seasons. Except for the limited air velocity correlation, the results presented very good agreement, particularly with respect to the final results of the PET visually curved and numerical values, with an index of agreement value ranging from 0.81 to 0.95. The study's conclusions concern the use of the ENVI-met simulation model as a tool for assessing outdoor thermal comfort.

Highlights

• Outdoor thermal comfort was investigated in a hot-humid climate.

• The effectiveness of using a Computational fluid dynamics (CFD) simulation software program such as ENVI-met was evaluated as an alternative technique in urban design.

• Varied environmental parameters and outdoor thermal comfort indices were evaluated.

• It was concluded that validating CFD simulation through field measurement was significant in offering integrated decisions for urban design.

Abbreviations: Environmental parameters; Ta; Air temperature; Tmrt; Mean radiant temperature; RH; Relative humidity; Va; Air velocity; Thermal comfort indices; PMV; Predicted mean vote; r; PPD; Predicted percentage of dissatisfaction; PET; Physiological Equivalent Temperature; UTCI; Universal Thermal Climate; UCB; University of California-Berkeley; ETU; universal effective temperature; Simulation Software; CFD; Computational fluid dynamics; UCB; University of California-Berkeley; LES; Large Eddy Simulation; RANS; Reynolds Averaged Navier Stoke; Error calculations; r; Pearson correlation coefficient; R2; Coefficient of determination; RMSE; Root Mean Squared Error; MAE; Mean Absolute Error; IA; Index of agreement; ASHRAE; American Society of Heating; Refrigeration; and Air-Conditioning Engineers.

KEYWORDS:

• Outdoor thermal comfort
• CFD simulation
• validation
• ENVI-met field measurement
• environmental parameters

Disclosure statement

No potential conflict of interest was reported by the author(s).