Page 25 - AWA Vol.41-No.8

HORTICULTURE

Features and advantages of double-layer greenhouses

With the development of modern agriculture, dou-
ble-layer greenhouses are gaining popularity. These
structures consist of two layers of transparent covering
material, creating an airtight air layer in between. Like
a "warm cotton coat," they offer multiple advantages,
including insulation, energy savings, and temperature
control.
1. Structural Features: Double-layer Protection Creates
a Three-Dimensional Space
Double-layer greenhouses build on traditional sin-
gle-layer greenhouses by adding an inner layer of film
or frame to create a "double insulation layer." Their core
construction includes:
1.Outer Frame and Covering: These typically uti- 2. Energy Saving and Consumption Reduction, Lower-
lize hot-dip galvanized steel pipes or aluminum alloy ing Operating Costs
frames, complemented by UV-resistant PE film, glass, or Reduced Heat Loss: The thermal resistance of the air
PC panels. They offer high resistance to wind (capable insulation layer is 2-3 times that of a single-layer film,
of withstanding winds of force 8 and above) and rain and reducing winter heating energy consumption by 30%-
snow erosion.
40%. For a 1,000 square meter greenhouse, for example,
2. Inner Insulation: By hanging an insulating screen a double-layer structure can save approximately 20 tons
(such as non-woven fabric or PVC film) or adding a of coal annually, equivalent to over 15,000 yuan in costs.
second layer of film, they create a 10-30 cm air insula-
tion layer with the outer layer, effectively blocking heat Efficient Water Utilization: Double-layer insulation re-
transfer between the interior and exterior. duces evaporation within the greenhouse. Combined
with a drip irrigation system, water consumption is re-
3. Supporting Equipment Integration: Often combined duced by 40% compared to traditional irrigation. It also
with ventilation systems (interconnected top and side reduces air humidity, minimizing the incidence of pests
windows), temperature control equipment (heating and diseases (e.g., the incidence of cucumber downy
furnaces, fans), irrigation systems (drip and sprinkler mildew can be reduced by 30%).
irrigation), and intelligent control systems, this system
achieves precise environmental control. 3. Strong environmental control improves crop quality
and yield.
II. Core Advantages: Triple Breakthroughs in Insula-
tion, Energy Saving, and Efficient Production Precise microclimate control: The intelligent tempera-
ture control system maintains a constant diurnal tem-
1. Excellent Insulation Performance, Extending the perature difference of 10-15°C (favoring sugar accu-
Growing Cycle
mulation in the fruit) and a humidity level of 60%-70%
Significant Winter Insulation: The double-layer struc- (reducing disease risks). For example, when growing
ture can raise the greenhouse temperature by 3-8°C strawberries, a double-layer greenhouse can increase
compared to single-layer greenhouses. In the harsh cold the sugar content of the fruit by 1-2 degrees and reduce
regions of northern China, combined with auxiliary heat- the rate of fruit deformities by 20%.
ing equipment, this system allows for the normal growth
of winter vegetables (such as cucumbers, tomatoes, and Enhanced stress resistance: The double-layer structure
other warm-loving crops) and prevents freezing dam- provides a stronger buffer against extreme weather con-
age. For example, in North China, single-layer green- ditions (cold waves, heavy rain, and strong ultraviolet
houses often experience nighttime temperatures below rays), ensuring more stable crop growth. Data shows that
0°C in winter, while double-layer greenhouses maintain vegetable yields in double-layer greenhouses increase
temperatures between 5-8°C, reducing heating energy by 15%-25% compared to single-layer greenhouses, and
consumption by over 50%. Summer Insulation and Cool- vegetables can be brought to market 10-15 days earlier,
ing: The outer covering can be made of shade netting preserving market demand during peak periods.
or reflective film, while the inner insulation curtain can Double-layer greenhouses are particularly suitable for
be deployed at noon, creating a dual cooling effect of high-latitude, cold regions, large-scale cultivation bases
"shading + air insulation," keeping the greenhouse tem- seeking high yields, and the cultivation of environmen-
perature 2-4°C lower than the outside temperature, al- tally sensitive cash crops. Their excellent energy-saving
leviating high-temperature stress on crops (e.g., during performance and stability make them crucial facilities in
summer cultivation of peppers and lettuce). modern agricultural production. Circle 23 on enquiry card
Vol. 41 No. 8 23