Energy Efficiency in Greenhouse Evaporative Cooling Techniques: Cooling Boxes versus Cellulose Pads
Evaporative cooling systems using a combination of evaporative pads and extractor fans require greenhouses to be hermetic. The greatest concentration of greenhouses in the world is located in southeast Spain, but these tend not to be hermetic structures and consequently can only rely on fogging syst...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2014-03-01
|
| Series: | Energies |
| Subjects: | |
| Online Access: | http://www.mdpi.com/1996-1073/7/3/1427 |
| _version_ | 1798042431027937280 |
|---|---|
| author | Antonio Franco Diego L. Valera Araceli Peña |
| author_facet | Antonio Franco Diego L. Valera Araceli Peña |
| author_sort | Antonio Franco |
| collection | DOAJ |
| description | Evaporative cooling systems using a combination of evaporative pads and extractor fans require greenhouses to be hermetic. The greatest concentration of greenhouses in the world is located in southeast Spain, but these tend not to be hermetic structures and consequently can only rely on fogging systems as evaporative cooling techniques. Evaporative cooling boxes provide an alternative to such systems. Using a low-speed wind tunnel, the present work has compared the performance of this system with four pads of differing geometry and thickness manufactured by two different companies. The results obtained show that the plastic packing in the cooling unit produces a pressure drop of 11.05 Pa at 2 m·s−1, which is between 51.27% and 94.87% lower than that produced by the cellulose pads. This pressure drop was not influenced by increases in the water flow. The evaporative cooling boxes presented greater saturation efficiency at the same flow, namely 82.63%, as opposed to an average figure of 65% for the cellulose pads; and also had a lower specific consumption of water, at around 3.05 L·h−1·m−2·°C−1. Consequently, we conclude that evaporative cooling boxes are a good option for cooling non-hermetic greenhouses such as those most frequently used in the Mediterranean basin. |
| first_indexed | 2024-04-11T22:35:26Z |
| format | Article |
| id | doaj.art-f114f941b9b1464291562f41184eeab4 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-04-11T22:35:26Z |
| publishDate | 2014-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-f114f941b9b1464291562f41184eeab42022-12-22T03:59:14ZengMDPI AGEnergies1996-10732014-03-01731427144710.3390/en7031427en7031427Energy Efficiency in Greenhouse Evaporative Cooling Techniques: Cooling Boxes versus Cellulose PadsAntonio Franco0Diego L. Valera1Araceli Peña2ETSIA, University of Sevilla, Ctra. Utrera km 1, 41013 Sevilla, SpainCentro de Investigación en Biotecnología Agroalimentaria—BITAL, University of Almería, Ctra. Sacramento s/n, 04120 Almería, SpainCentro de Investigación en Biotecnología Agroalimentaria—BITAL, University of Almería, Ctra. Sacramento s/n, 04120 Almería, SpainEvaporative cooling systems using a combination of evaporative pads and extractor fans require greenhouses to be hermetic. The greatest concentration of greenhouses in the world is located in southeast Spain, but these tend not to be hermetic structures and consequently can only rely on fogging systems as evaporative cooling techniques. Evaporative cooling boxes provide an alternative to such systems. Using a low-speed wind tunnel, the present work has compared the performance of this system with four pads of differing geometry and thickness manufactured by two different companies. The results obtained show that the plastic packing in the cooling unit produces a pressure drop of 11.05 Pa at 2 m·s−1, which is between 51.27% and 94.87% lower than that produced by the cellulose pads. This pressure drop was not influenced by increases in the water flow. The evaporative cooling boxes presented greater saturation efficiency at the same flow, namely 82.63%, as opposed to an average figure of 65% for the cellulose pads; and also had a lower specific consumption of water, at around 3.05 L·h−1·m−2·°C−1. Consequently, we conclude that evaporative cooling boxes are a good option for cooling non-hermetic greenhouses such as those most frequently used in the Mediterranean basin.http://www.mdpi.com/1996-1073/7/3/1427greenhouseevaporative coolingpressure dropheat and mass transfer coefficientsspecific water consumptionsaturation efficiency |
| spellingShingle | Antonio Franco Diego L. Valera Araceli Peña Energy Efficiency in Greenhouse Evaporative Cooling Techniques: Cooling Boxes versus Cellulose Pads Energies greenhouse evaporative cooling pressure drop heat and mass transfer coefficients specific water consumption saturation efficiency |
| title | Energy Efficiency in Greenhouse Evaporative Cooling Techniques: Cooling Boxes versus Cellulose Pads |
| title_full | Energy Efficiency in Greenhouse Evaporative Cooling Techniques: Cooling Boxes versus Cellulose Pads |
| title_fullStr | Energy Efficiency in Greenhouse Evaporative Cooling Techniques: Cooling Boxes versus Cellulose Pads |
| title_full_unstemmed | Energy Efficiency in Greenhouse Evaporative Cooling Techniques: Cooling Boxes versus Cellulose Pads |
| title_short | Energy Efficiency in Greenhouse Evaporative Cooling Techniques: Cooling Boxes versus Cellulose Pads |
| title_sort | energy efficiency in greenhouse evaporative cooling techniques cooling boxes versus cellulose pads |
| topic | greenhouse evaporative cooling pressure drop heat and mass transfer coefficients specific water consumption saturation efficiency |
| url | http://www.mdpi.com/1996-1073/7/3/1427 |
| work_keys_str_mv | AT antoniofranco energyefficiencyingreenhouseevaporativecoolingtechniquescoolingboxesversuscellulosepads AT diegolvalera energyefficiencyingreenhouseevaporativecoolingtechniquescoolingboxesversuscellulosepads AT aracelipena energyefficiencyingreenhouseevaporativecoolingtechniquescoolingboxesversuscellulosepads |