Effects of Vent Configuration and Span Number on Greenhouse Microclimate under Summer Conditions in Eastern China
- Resource Type
- Authors
- Keshi He; Zhenglu Liu; Zhenyu Huang; Lijuan Sun; Dayue Chen
- Source
- International Journal of Ventilation. 13:381-396
- Subject
- Engineering
Meteorology
business.industry
Microclimate
Humidity
Greenhouse
Natural ventilation
Building and Construction
Computational fluid dynamics
Atmospheric sciences
Span (engineering)
law.invention
Control and Systems Engineering
law
Ventilation (architecture)
Electrical and Electronic Engineering
business
Roof
Civil and Structural Engineering
- Language
- ISSN
- 2044-4044
1473-3315
The effects of vent configuration and span number on the microclimate in multi-span greenhouses were investigated. A three-dimensional (3-D) computational fluid dynamics (CFD) model was constructed based on an 11-span plastic greenhouse cultivated with 0.2 m-high lettuces. The model was verified with the temperature profile measured in the greenhouse. Then, it was used to explore the effects of vent configuration and span number on greenhouse climate. Simulations show that different vent configurations result in very different microclimate fields. Roof plus side opening has the best cooling and homogeneity performance and is thus recommended. The side openings, the first two windward roof openings and the last two roof openings play a central role during the ventilation process. A minor modification of the ventilation system induces a temperature decrease of 0.1 K and a humidity elevation of 0.3% and increases greenhouse climate homogeneity. These simulations also show that the ventilation rate ex...