http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WXV-4P481W4- 2&_user=6763742&_coverDate=09%2F30%2F2007&_rdoc=1&_fmt=high&_orig=search&_sort=d&_doca nchor=&view=c&_searchStrId=1366521828&_rerunOrigin=scholar.google&_acct=C000070526&_versio n=1&_urlVersion=0&_userid=6763742&md5=63e1e038d8e8c0ee0c7a3295c290673e Simple greenhouse climate model as a design tool for greenhouses in tropical lowland I. Impron a , b , , S. Hemming b and G.P.A. Bot b , c a Department of Geophysics and Meteorology, Faculty of Mathematics and Natural Sciences, Bogor Agricultural University, Darmaga Campus Wing 19 Level 4, Bogor, Indonesia b Wageningen University and Research Centre, Plant Research International, Greenhouse Technology, P.O. Box 16, 6700 AA Wageningen, The Netherlands c Wageningen University, Systems and Control Group, P.O. Box 17, 6700 AA Wageningen, The Netherlands Received 22 March 2006; accepted 30 March 2007. Available online 5 July 2007. Abstract Six prototypes plastic greenhouses were built in the tropical lowlands of Indonesia. The geometrical dimensions were designed using computational fluid dynamics (CFD) by taking local climate parameters as static reference boundary conditions. It is necessary to evaluate the climate dynamics inside the greenhouse during varying climatological conditions. A greenhouse climate model was developed to optimise cover properties and ventilation rate as main parameters, calculating only three state variables: average greenhouse air temperature T Air , average greenhouse air water vapour pressure (expressed as air water vapour pressure deficit D Air ), and average canopy temperature T Can . Solar radiation distribution, air exchange by ventilation, and crop transpiration constituted the backbones of the model. The climate outdoor and inside the test greenhouses with crops having leaf area index from 0.02 to 4.10 were measured for one growing season. Measurements and calculations of T Air and D Air agreed satisfactorily, with less than 5% errors. It is concluded that the model is robust and could be used as a design tool for the tropical lowland greenhouses. Nomenclature A area, m 2 C coefficient c