SE—Structures and Environment: A Strategy for Greenhouse Climate Control, Part II: Model Validation

✍ Scribed by M. Trigui; S. Barrington; L. Gauthier

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 264 KB
• Volume: 79
• Category: Article
• ISSN: 0021-8634
• DOI: 10.1006/jaer.2000.0648

✦ Synopsis

The present project tested a model predicting the dynamic ambient greenhouse air conditions maximizing a tomato crop yield value less the energy cost. For simpli"cation, this yield value less energy cost is referred to as net pro"ts. Net pro"ts were equated to crop yield value, computed from the dynamic greenhouse conditions (temperature, incident radiation, CO level and relative humidity), less the costs of heating, dehumidi"cation and CO injection. The physical parameters describing a Venlo-type glass greenhouse located in QueH bec City, Canada, were measured to describe its heat and mass (CO and water vapour) transfers and test the model. The model was used to predict net pro"ts for 2 months of tomato production. The measured values were compared to that calculated by the sub-models (transpiration rate and tomato yield) and the model itself. The sub-models and model proved to be accurate within a 3% error when used to predict crop yield and net pro"ts for periods of 1 week or longer. The model was found to be especially sensitive to exterior temperature, a!ecting heating costs but not yield, then incident radiation reducing heating costs and increases yield through transpiration, and "nally, relative humidity a!ecting crop yield and dehumidi"cation costs.