Iranian Journal of Biosystem Engineering

Iranian Journal of Biosystem Engineering

Comparative Evaluation of Ventilation Capacity, Microclimate Quality, and Crop-Zone Thermal Conditions in Buoyancy-Driven and Wind-Driven Natural Ventilation Systems under Hot-Arid Climatic Conditions of Ahvaz

Articles in Press

Document Type : Research Paper

Authors
Seyed Majid Sajadiye
Ayad Saberian
Department of Biosystems Engineering, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
10.22059/ijbse.2026.417256.665653
Abstract
Natural ventilation is an effective strategy for greenhouse microclimate control and energy conservation. However, its performance is commonly evaluated based on air exchange rate, while its impact on thermal conditions within the crop growth zone remains less explored. This study comparatively evaluated wind-driven natural ventilation and wall-mounted solar chimney-assisted natural ventilation in a greenhouse located in the hot-arid climate of Ahvaz, Iran, using three-dimensional computational fluid dynamics simulations. Analyses were conducted under realistic temperature, solar radiation, and wind conditions during March, April, and October. The wind-driven system achieved a higher ventilation capacity, with an average air exchange rate of 5.36 h⁻¹ compared with 1.75 h⁻¹ for the solar chimney-assisted system. Despite this, the solar chimney produced a more stable and organized airflow pattern, reducing stagnant zones and air recirculation within the greenhouse. As a result, the average canopy temperature decreased from 38.93 to 36.96 °C, the temperature uniformity index increased from 0.75 to 0.91, and the canopy cooling effectiveness index improved from 0.14 to 0.54. The solar chimney also achieved an average thermal efficiency of 6.63%. The findings demonstrate that air exchange rate alone is insufficient for evaluating natural ventilation performance. Greater emphasis should be placed on microclimate quality and thermal conditions within the crop growth zone. Overall, the wall-mounted solar chimney improved airflow organization and thermal performance, highlighting its potential as a passive and sustainable solution for greenhouse climate control in hot-arid regions.
Keywords
Computational Fluid Dynamics (CFD)
Greenhouse Microclimate
Natural Ventilation
Solar Chimney
Sustainable Greenhouse
Iranian Journal of Biosystem Engineering

Articles in Press, Accepted Manuscript
Available Online from 11 August 2026

  • Receive Date 24 June 2026
  • Revise Date 25 July 2026
  • Accept Date 11 August 2026