TITLE:
Technology and Studies for Greenhouse Cooling
AUTHORS:
Hugang Li, Shuangxi Wang
KEYWORDS:
Greenhouse Cooling Technologies and Studies, Natural Ventilation, Evaporation Cooling, Shading
JOURNAL NAME:
World Journal of Engineering and Technology,
Vol.3 No.3B,
August
25,
2015
ABSTRACT: Greenhouse technology is an efficient and
viable option, especially for the sustainable crop production in the regions of
adverse climatic conditions. High summer temperature is one of the worst
effects on greenhouse crop production throughout the year. The main purpose of
this paper is to present some technologies and studies for greenhouse cooling
in summer. In the paper, some applicable and practical cooling technologies
have been discussed. The choice of efficient cooling method depends on many
aspects, such as local climate, agronomic condition, design and covering materials.
To achieve desirable benefits, the combination of different cooling methods is
necessarily used. Analysis of earlier studies revealed that a naturally
ventilated greenhouse with larger ventilation areas (15% - 30%), provided at
the ridge and side covered with insect-proof nets of 20 - 40 mesh size with
covering material properties of NIR (near infrared radiation) reflection during
the day and FIR (far infrared radiation) reflection during night was suitable
for greenhouse production throughout year in some special regions. Evaporation
cooling is the most effective cooling method for controlling the temperature
and humidity inside a greenhouse. However, its suitability is restricted to the
respective region and climate when the humidity level is high. The entry of unwanted radiation or light can be controlled by the use of shading. Researches
show that shade net application with different perforated mesh size and their
evaluation with respect to local climate and region are necessary to get
cooling benefits in summer.