Thermal analysis of a modular plant growth chamber: Experiments and numerical simulation

Abstract

India, an agriculture-based economy, is the second-largest producer of vegetable crops globally. However, the seasonal and weather-dependent nature of these crops poses significant challenges, prompting a growing adoption of technologies like protected farming. Introduced to India in 1998 through the Indo-Israel Greenhouse Project, greenhouse farming has expanded rapidly but brought unique challenges, especially the issue of overheating during the summer months. India’s abundant sunlight, particularly in summer, often results in temperatures inside greenhouses exceeding optimal levels for plant growth. To address this, evaporative cooling systems, such as pad-and-fan setups, are commonly employed. However, these systems signifi cantly increase water consumption, contradicting one of the primary objectives of protected farming—efficient resource usage, particularly water. The focus of this work is to quantify the extent of overheating in a lab-scale greenhouse model and explore the potential of Infrared (IR) filtering to mitigate this issue. Experimental results demonstrate the effectiveness of IR filters in reducing overheating, offering a promising solution to this challenge. Additionally, this study presents a comprehensive approach to predicting bulk air temperature inside greenhouses through two methodologies: Computational Fluid Dynamics (CFD) simulations and a simplified lumped mass reduced-order model. Both models exhibit good accuracy in temperature prediction, providing valuable tools for optimizing greenhouse designs and ensuring favorable growing conditions with efficient resource usage.