Determination of Greenhouse-specific Aspects of Ventilation using Three-dimensional Computational Fluid Dynamics

The ventilation of a Spanish ‘parral’ greenhouse was studied using three-dimensional computational fluid dynamics (CFD). The calculations were verified by experimental results from tracer gas measurements. Two types of roof openings have been considered; the rollup window configuration and the flap window configuration. The calculations resembled experimental data within 15%. The wind speed correlated linearly with ventilation rate for both configurations without the buoyancy effect. This is in agreement with the basic theory on ventilation. The CFD calculations indicated that ventilation rate for both configurations is largely dependent on wind direction, which was also seen with the experimental data. Ventilation rate varied for the flap window configuration from 0·8 to almost 4 renewals per hour per m s−1 wind speed.