Predicting the energy consumption of heated plastic greenhouses in south-eastern Spain

  1. López, J. C.
  2. Bonachela Castaño, Santiago
  3. Baille, Alain
  4. González Real, María Milagros
  5. Pérez Parra, Jerónimo
  6. Pérez Parra, J. J.
Journal:
Spanish journal of agricultural research

ISSN: 1695-971X 2171-9292

Year of publication: 2006

Issue: 4

Pages: 289-296

Type: Article

DOI: 10.5424/SJAR/2006044-206 DIALNET GOOGLE SCHOLAR lock_openDialnet editor

More publications in: Spanish journal of agricultural research

Abstract

Measurements of heat consumption in a parral type greenhouse, equipped with an air-heating system, were carried out in south-eastern Spain (Almería) during the 1998/99 winter. From the daily values of heat consumption (Qd, MJ m-2 d-1) recorded in five identical greenhouses heated to different night temperature set-points (Tc), and data of minimum outside air temperature (Te,min), relationships between Qd and the temperature difference (DTmin = Tc - Te,min) were established. Linear regressions between Qd and DTmin gave satisfactory fits (R2 ranging from 0.75 to 0.83), considering that Te,min was the only input data for the model. When all data were pooled, the correlation was curvilinear, the best fit to a 2nd order polynomial being Qd = 0.049 DTmin2 - 0.001 DTmin + 1.107 (R2 = 0.89). Validation of this model was performed using data obtained during other years, giving a fair agreement at the daily (R2 = 0.86), 10-day (R2 = 0.95) and yearly (R2 = 0.99) time scales. This simple model could be of interest to growers for decision-making related to the choice of set-point temperature and crop planning in heated greenhouses.