Evaluation of New Passive Heating Systems for Low-Cost Greenhouses in a Mild-Winter Area
The main objective of this work was to evaluate new variants of passive heating systems used for horticultural crop cycles planted in the cold period in low-cost greenhouses on the Mediterranean Spanish coast (a mild-winter area). The double low cover (DLC) is variant of the conventional fixed plast...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-07-01
|
| Series: | Horticulturae |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2311-7524/11/7/752 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849407057338302464 |
|---|---|
| author | Santiago Bonachela María Cruz Sánchez-Guerrero Juan Carlos López Evangelina Medrano Joaquín Hernández |
| author_facet | Santiago Bonachela María Cruz Sánchez-Guerrero Juan Carlos López Evangelina Medrano Joaquín Hernández |
| author_sort | Santiago Bonachela |
| collection | DOAJ |
| description | The main objective of this work was to evaluate new variants of passive heating systems used for horticultural crop cycles planted in the cold period in low-cost greenhouses on the Mediterranean Spanish coast (a mild-winter area). The double low cover (DLC) is variant of the conventional fixed plastic screen that reduces the air volume and increases the airtightness around crops. Three identical DLCs were installed inside a typical greenhouse, and the microclimate measured in the three DLCs was similar. The DLCs reduced the solar radiation transmissivity coefficient by around 0.05 but increased the mean daily substrate and air temperatures (up to 1.6 and 3.6 °C, respectively). They also modified the air humidity, although this can be modulated by opening the vertical sheets located on the greenhouse aisles (DLC vents). The black plastic mulch forming an air chamber around the substrate bags (BMC), a new mulch variant used in substrate-grown crops, increased the substrate temperature with respect to the conventional black mulch covering the entire ground surface. The combination of BMC plus DLC increased the mean daily substrate temperature by up to 2.9 °C, especially at night. Low tunnels covered with transparent film and with a spun-bonded fabric sheet were also compared, and both materials were efficient heating systems regarding substrate and air temperatures. Low tunnels combined with the DLC substantially increased air humidity, but this can be partially offset by opening the DLC vents. The combination of low tunnels and DLC does not seem recommendable for greenhouse crops planted in winter, since both systems reduce solar radiation transmissivity. |
| format | Article |
| id | doaj-art-b2c0e68be2ba4ed587b58317fc0a2e9d |
| institution | Kabale University |
| issn | 2311-7524 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Horticulturae |
| spelling | doaj-art-b2c0e68be2ba4ed587b58317fc0a2e9d2025-08-20T03:36:11ZengMDPI AGHorticulturae2311-75242025-07-0111775210.3390/horticulturae11070752Evaluation of New Passive Heating Systems for Low-Cost Greenhouses in a Mild-Winter AreaSantiago Bonachela0María Cruz Sánchez-Guerrero1Juan Carlos López2Evangelina Medrano3Joaquín Hernández4Departamento de Agronomía, Centro de Investigación en Agrosistemas Intensivos Mediterráneos y Biotecnología Agroalimentaria (CIAMBITAL), Universidad de Almería, La Cañada de San Urbano s/n, 04120 Almería, SpainAndalusian Institute for Research and Training in Agriculture, Fishery, Food and Ecological Production (IFAPA), Center La Mojonera, 04745 Almería, SpainDepartamento de Agronomía, Centro de Investigación en Agrosistemas Intensivos Mediterráneos y Biotecnología Agroalimentaria (CIAMBITAL), Universidad de Almería, La Cañada de San Urbano s/n, 04120 Almería, SpainAndalusian Institute for Research and Training in Agriculture, Fishery, Food and Ecological Production (IFAPA), Center La Mojonera, 04745 Almería, SpainDepartamento de Agronomía, Centro de Investigación en Agrosistemas Intensivos Mediterráneos y Biotecnología Agroalimentaria (CIAMBITAL), Universidad de Almería, La Cañada de San Urbano s/n, 04120 Almería, SpainThe main objective of this work was to evaluate new variants of passive heating systems used for horticultural crop cycles planted in the cold period in low-cost greenhouses on the Mediterranean Spanish coast (a mild-winter area). The double low cover (DLC) is variant of the conventional fixed plastic screen that reduces the air volume and increases the airtightness around crops. Three identical DLCs were installed inside a typical greenhouse, and the microclimate measured in the three DLCs was similar. The DLCs reduced the solar radiation transmissivity coefficient by around 0.05 but increased the mean daily substrate and air temperatures (up to 1.6 and 3.6 °C, respectively). They also modified the air humidity, although this can be modulated by opening the vertical sheets located on the greenhouse aisles (DLC vents). The black plastic mulch forming an air chamber around the substrate bags (BMC), a new mulch variant used in substrate-grown crops, increased the substrate temperature with respect to the conventional black mulch covering the entire ground surface. The combination of BMC plus DLC increased the mean daily substrate temperature by up to 2.9 °C, especially at night. Low tunnels covered with transparent film and with a spun-bonded fabric sheet were also compared, and both materials were efficient heating systems regarding substrate and air temperatures. Low tunnels combined with the DLC substantially increased air humidity, but this can be partially offset by opening the DLC vents. The combination of low tunnels and DLC does not seem recommendable for greenhouse crops planted in winter, since both systems reduce solar radiation transmissivity.https://www.mdpi.com/2311-7524/11/7/752air temperatureblack mulchfixed screenlow tunnelpassive heating systemradiation |
| spellingShingle | Santiago Bonachela María Cruz Sánchez-Guerrero Juan Carlos López Evangelina Medrano Joaquín Hernández Evaluation of New Passive Heating Systems for Low-Cost Greenhouses in a Mild-Winter Area Horticulturae air temperature black mulch fixed screen low tunnel passive heating system radiation |
| title | Evaluation of New Passive Heating Systems for Low-Cost Greenhouses in a Mild-Winter Area |
| title_full | Evaluation of New Passive Heating Systems for Low-Cost Greenhouses in a Mild-Winter Area |
| title_fullStr | Evaluation of New Passive Heating Systems for Low-Cost Greenhouses in a Mild-Winter Area |
| title_full_unstemmed | Evaluation of New Passive Heating Systems for Low-Cost Greenhouses in a Mild-Winter Area |
| title_short | Evaluation of New Passive Heating Systems for Low-Cost Greenhouses in a Mild-Winter Area |
| title_sort | evaluation of new passive heating systems for low cost greenhouses in a mild winter area |
| topic | air temperature black mulch fixed screen low tunnel passive heating system radiation |
| url | https://www.mdpi.com/2311-7524/11/7/752 |
| work_keys_str_mv | AT santiagobonachela evaluationofnewpassiveheatingsystemsforlowcostgreenhousesinamildwinterarea AT mariacruzsanchezguerrero evaluationofnewpassiveheatingsystemsforlowcostgreenhousesinamildwinterarea AT juancarloslopez evaluationofnewpassiveheatingsystemsforlowcostgreenhousesinamildwinterarea AT evangelinamedrano evaluationofnewpassiveheatingsystemsforlowcostgreenhousesinamildwinterarea AT joaquinhernandez evaluationofnewpassiveheatingsystemsforlowcostgreenhousesinamildwinterarea |