The effect of vent configuration and insect screens on greenhouse microclimate

Abstract

The influence of insect screens and vent configurations on airflow and temperature patterns in an arched plastic covered greenhouse used for cultivating tomatoes was analysed using a commercial computational fluid dynamics (CFD) code. The numerical model was first validated against experimental measurements which were carried out in an equivalent greenhouse incorporating continuous side openings. Measurement data included the three Cartesian components of air velocity, determined by means of a sonic anemometer, and the spatial distribution of air temperature measured using a fast response temperature sensor. The experimental data were used to define proper and realistic boundary conditions for use in the numerical model. Numerical results predicted a gradual increase of air temperature and a decrease of air velocity as the porosity of the tested insect screen was reduced. It was found that vent configuration affects the ventilation rate and the climate distribution inside the greenhouse.