Influence of Heating System on Greenhouse Microclimate Distribution

Tadj, Nacima; Bartzanas, Thomas; Fidaros, D.; Draoui, Belkacem; Kittas, C.

doi:10.13031/2013.29498

Cited by 26 publications

(34 citation statements)

References 31 publications

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“…While these structures allow suitable conditions for crop development to be maintained during most of the year, extreme heat or cold conditions can lead to crop damage and therefore economic losses. The problem of low temperatures during winter can be solved by supplying some heat to the greenhouse during the critical periods [1,2]. Conventionally, thermal energy is transferred to the greenhouse either by circulation of hot water through a piping system or by air heaters [3,4].…”

Section: Introductionmentioning

confidence: 99%

“…Conventionally, thermal energy is transferred to the greenhouse either by circulation of hot water through a piping system or by air heaters [3,4]. Pipe heating is an effective means of maintaining an appropriate temperature for crops, both by convectively heating the greenhouse air and by radiating heat directly to the leaves, and it is the most common greenhouse heating system [1,2]. …”

Section: Introductionmentioning

confidence: 99%

“…Greenhouse heating is essential, even in areas with mild temperate climates, like the Mediterranean region, in order to maximize crop production in terms of quantity and quality and thus to increase the overall greenhouse efficiency [2]. Air heaters are used for heating greenhouse air either alone or in combination with heating pipes [2].…”

Section: Introductionmentioning

confidence: 99%

“…Air heaters are used for heating greenhouse air either alone or in combination with heating pipes [2]. This combination can increase temperatures by 5 °C compared to using heating pipes alone, but it also implies a 19% increase in energy consumption [1] and a more heterogeneous climate distribution [2]. …”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Thermography and Sonic Anemometry to Analyze Air Heaters in Mediterranean Greenhouses

López

Valera

Molina-Aiz

et al. 2012

Sensors

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Abstract:The present work has developed a methodology based on thermography and sonic anemometry for studying the microclimate in Mediterranean greenhouses equipped with air heaters and polyethylene distribution ducts to distribute the warm air. Sonic anemometry allows us to identify the airflow pattern generated by the heaters and to analyze the temperature distribution inside the greenhouse, while thermography provides accurate crop temperature data. Air distribution by means of perforated polyethylene ducts at ground level, widely used in Mediterranean-type greenhouses, can generate heterogeneous temperature distributions inside the greenhouse when the system is not correctly designed. The system analyzed in this work used a polyethylene duct with a row of hot air outlet holes (all of equal diameter) that expel warm air toward the ground to avoid plant damage. We have observed that this design (the most widely used in Almerí a's greenhouses) produces stagnation of hot air in the highest part of the structure, reducing the heating of the crop zone. Using 88 kW heating power (146.7 W•m −2 ) the temperature inside the greenhouse is maintained 7.2 to 11.2 °C above the outside temperature. The crop temperature (17.6 to 19.9 °C) was maintained above the minimum recommended value of 10 °C.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Thermography and Sonic Anemometry to Analyze Air Heaters in Mediterranean Greenhouses

López

Valera

Molina-Aiz

et al. 2012

Sensors

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“…It was pointed out that measuring with only one sensor near the center of the greenhouse would overestimate the average temperature of the entire area. Tadj et al (2010) investigated distribution of temperature and humidity in greenhouse by different heating methods. The experiments were performed in a tomato growing greenhouse of 8 × 20 m 2 size, in which the heating pipes at the bottom and a heater at the upper were used for heating.…”

Section: Introductionmentioning

confidence: 99%

Spatial, Vertical, and Temporal Variability of Ambient Environments in Strawberry and Tomato Greenhouses in Winter

Ryu

Chung

et al. 2014

Journal of Biosystems Engineering

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Purpose:In protected crop production facilities such as greenhouse and plant factory, farmers should be present and/or visit frequently to the production site for maintaining optimum environmental conditions and better production, which is time and labor consuming. Monitoring of environmental condition is highly important for optimum control of the conditions, and the condition is not uniform within the facility. Objectives of the paper were to investigate spatial and vertical variability in ambient environmental variables and to provide useful information for sensing and control of the environments. Methods: Experiments were conducted in a strawberry-growing greenhouse (greenhouse 1) and a cherry tomato-growing greenhouse (greenhouse 2). Selected ambient environmental variables for experiment in greenhouse 1 were air temperature and humidity, and in greenhouse 2, they were air temperature, humidity, PPFD (Photosynthetic Photon Flux Density), and CO2 concentration. Results: Considerable spatial, vertical, and temporal variability of the ambient environments were observed. In greenhouse 1, overall temperature increased from 12:00 to 14:00 and increased after that, while RH increased continuously during the experiments. Differences between the maximum and minimum temperature and RH values were greater when one of the side windows were open than those when both of the windows were closed. The location and height of the maximum and minimum measurements were also different. In greenhouse 2, differences between the maximum and minimum air temperatures at noon and sunset were greater when both windows were open. The maximum PPFD were observed at a 3-m height, close to the lighting source, and CO2 concentration in the crop growing regions. Conclusions: In this study, spatial, vertical, and temporal variability of ambient crop growing conditions in greenhouses was evaluated. And also the variability was affected by operation conditions such as window opening and heating. Results of the study would provide information for optimum monitoring and control of ambient greenhouse environments.

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Comparison of heating modules for suspension-type multipoint temperature variability management in smart greenhouses

Iqbal,

Islam,

Kabir

et al. 2023

Smart Agricultural Technology

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Influence of Heating System on Greenhouse Microclimate Distribution

Cited by 26 publications

References 31 publications

Thermography and Sonic Anemometry to Analyze Air Heaters in Mediterranean Greenhouses

Thermography and Sonic Anemometry to Analyze Air Heaters in Mediterranean Greenhouses

Spatial, Vertical, and Temporal Variability of Ambient Environments in Strawberry and Tomato Greenhouses in Winter

Comparison of heating modules for suspension-type multipoint temperature variability management in smart greenhouses

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