Articles
Analysis of temperature and humidity in a large-scale asymmetric plastic-covered greenhouse with a water-controlled brewed hot system
Article number
1227_21
Pages
173 – 180
Language
English
Abstract
In order to address low land-use efficiency, an unfriendly mechanization environment, and other problems in Chinese solar greenhouses, a new, large-scale asymmetric plastic-covered tunnel with a water-controlled brewed hot system (an experimental greenhouse, GH-F) was designed.
GH-F is oriented in the east-west direction and has a double roof with a wide steel frame.
The sun projection on the south and north roof is 10-12 and 7-8 m, respectively.
It also has a 1×0.5 m2 fermentation groove in the north roof.
The experiment was conducted from 15 December 2015 and 5 February 2016. We compared the results between a traditional brick-structure greenhouse (GH-D) and GH-F for temperature exchange, humidity exchange, and building expenses.
Our results showed that GH-F had both thermal insulation and economic benefits.
The highest temperature difference between GH-F and the environment was 21.9°C during winter.
The average night air temperature in GH-F was kept above 8°C, which was only 1°C lower than that in GH-D. This difference was consistent during cloudy and non-cloudy nights.
Temperatures in the GH-F system were higher than the environmental temperature, ranging from 11.1 to 15.3°C during non-cloudy nights, 8.5-11.7°C during cloudy nights, and 12.3-13.7°C during snowy nights.
However, the system temperature difference between GH-F and GH-D during snowy nights was dependent on time.
The relative humidity in GH-F was 2-7% lower than that in GH-D at night.
The initial cost for GH-F was 200 yuan m-2, which was 20.3% lower than the cost of GH-D. In summary, GH-F can improve land-use efficiency, increase thermal insulation, and decrease initial building costs and relative system humidity.
Thus, GH-F is an appropriate design for vegetable production in northwestern and mid-eastern areas of China, especially in areas that are primarily sunny during winter.
GH-F is oriented in the east-west direction and has a double roof with a wide steel frame.
The sun projection on the south and north roof is 10-12 and 7-8 m, respectively.
It also has a 1×0.5 m2 fermentation groove in the north roof.
The experiment was conducted from 15 December 2015 and 5 February 2016. We compared the results between a traditional brick-structure greenhouse (GH-D) and GH-F for temperature exchange, humidity exchange, and building expenses.
Our results showed that GH-F had both thermal insulation and economic benefits.
The highest temperature difference between GH-F and the environment was 21.9°C during winter.
The average night air temperature in GH-F was kept above 8°C, which was only 1°C lower than that in GH-D. This difference was consistent during cloudy and non-cloudy nights.
Temperatures in the GH-F system were higher than the environmental temperature, ranging from 11.1 to 15.3°C during non-cloudy nights, 8.5-11.7°C during cloudy nights, and 12.3-13.7°C during snowy nights.
However, the system temperature difference between GH-F and GH-D during snowy nights was dependent on time.
The relative humidity in GH-F was 2-7% lower than that in GH-D at night.
The initial cost for GH-F was 200 yuan m-2, which was 20.3% lower than the cost of GH-D. In summary, GH-F can improve land-use efficiency, increase thermal insulation, and decrease initial building costs and relative system humidity.
Thus, GH-F is an appropriate design for vegetable production in northwestern and mid-eastern areas of China, especially in areas that are primarily sunny during winter.
Authors
X. Hu, X. Song, J. Xiao, Y. Guo, J. Li
Keywords
GH-F, temperature, relative humidity, building cost
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