Theoretische, messtechnische und anwendungsbezogene Bewertung von U’-bezogenen Energiverbrauchsberechnungen von Gewächshäusern und deren Realisierung in einem Softwaresystem

Abstract

Simulating the energy consumption of greenhouses provides significant advantages for planning their construction or estimating the effectiveness of reconstruction measures. A substantial number of models used today derive from a simple model by Kanthak in 1970. To this day neither a theoretical nor a practical comparison of these developments has been conducted. Therefore, this study aims to qualitatively and quantitatively compare four representative models that are based on Kanthak. The best performing model is implemented into a software program. To quantitatively compare models, a test stand was developed. The resulting measurement box was then used to parameterize environmental variables to compare and evaluate the models. The results from the test stand showed that models, which accounted for cloudiness and windspeed, outperformed other models. A model developed by Tantau and Akyazi in 2014 delivered the most accurate results. However, these model prediction accuracies could not be reproduced under applied greenhouse conditions in the field. Here, the model developed by Rath in 1992 showed best accuracy. This model was therefore used as the core algorithm in the new iteration of the software system HORTEX© To increase prediction accuracy and to enable future software development, the majority of algorithms and functions in the original HORTEX©were restructured and replaced. The resulting software, distributed by the Eugen Ulmer KG publisher as Hortex 5.0©, contributes to improving the energy consumption of greenhouses.