Greenhouses naturally trap heat, so finding an effective way to cool them is essential. One popular method is using shade cloths. Shade cloths are also known as energy curtains, shades, thermal curtains, screens, heat retention curtains, or blankets. They’re designed to help control greenhouse temperatures by creating shade or retaining heat when needed.
In commercial greenhouses, cooling is rarely managed through a single approach. Shade cloths are often used alongside ventilation and humidity control to help maintain stable growing conditions as external temperatures rise. Learn more about cooling down greenhouses here.
Shade cloths are typically used when energy consumption is high, solar radiation is intense, or humidity levels are too low. Their design consists of moveable panels made from fabric or plastic film that shield the enclosed greenhouse space. Depending on the setup, shade cloths can also be automated using climate data.
Accurate temperature and humidity data helps growers decide when shade cloths should be deployed. It also helps determine whether shading is reducing plant stress or creating new challenges elsewhere in the greenhouse.
Greenhouses naturally trap heat, so finding an effective way to cool them is essential. One popular method is using shade cloths. Shade cloths are also known as energy curtains, shades, thermal curtains, screens, heat retention curtains, or blankets. They’re designed to help control greenhouse temperatures by creating shade or retaining heat when needed.
In commercial greenhouses, cooling is rarely managed through a single approach. Shade cloths are often used alongside ventilation and humidity control to help maintain stable growing conditions as external temperatures rise. Learn more about cooling down greenhouses here.
Shade cloths are typically used when energy consumption is high, solar radiation is intense, or humidity levels are too low. Their design consists of moveable panels made from fabric or plastic film that shield the enclosed greenhouse space. Depending on the setup, shade cloths can also be automated using climate data.
Accurate temperature and humidity data helps growers decide when shade cloths should be deployed. It also helps determine whether shading is reducing plant stress or creating new challenges elsewhere in the greenhouse.
Shade cloth cooling tips for greenhouses
When selecting a shade cloth, the weave density has a significant impact on greenhouse conditions. A looser weave can help manage excessive humidity{link}, while a tighter weave traps both humidity and heat.
Because shade cloths influence humidity levels, they work best when combined with good airflow and ventilation. Without adequate air movement, cooling strategies can increase humidity and raise the risk of disease.
Radiant cooling {correct link} can help prevent sharp temperature drops overnight and reduce plant stress in colder climates. Cool air trapped between the curtain and the greenhouse roof can be released gradually in the morning. This allows it to mix with warmer air below and avoids sudden temperature changes.
Managing temperature changes gradually is especially important in greenhouses that use heating systems. Rapid fluctuations can stress plants and lead to uneven conditions across growing zones.
It’s also important to control how much solar energy plants are exposed to. Shade screens can help protect the tips of leafy greens from burning. Monitoring moisture levels and overall greenhouse temperature remains essential.
The most suitable shade cloth configuration depends on your greenhouse structure, crop type, and how other climate systems, such as ventilation and heating, are set up.
There are three main ways shade cloths can be used in a greenhouse: sidewall curtains, gutter-to-gutter systems, and truss-to-truss systems.
Option 1: Sidewall Curtains
Sidewall curtains help maximise natural ventilation{link} by allowing heat to escape as fresh air enters the greenhouse. There are three common ways to raise and lower sidewall curtains:
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The curtain material wraps around a tube and is raised or lowered using a hand crank or electric motor.
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Ropes and pulleys are attached to the top edge of the curtain, allowing it to be dropped open or lifted closed.
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The material is rolled and unrolled around a tube that rotates through rope loops connected to pulleys. These are operated by a hand crank or a motorised lead screw.
Option 2: Gutter-to-Gutter System
Gutter-to-gutter systems reduce the volume of air inside the greenhouse. Curtains are pulled flat across the width of the structure at gutter height. However, this system isn’t suitable for all greenhouses.
One disadvantage is that circulation fans{link} mounted at gutter level may be blocked, limiting airflow beneath the curtain where crops are grown. Existing gas lines, electrical conduits, or heating pipes at gutter height may also need to be relocated. Hanging baskets can’t be used, as they interfere with curtain movement.
Despite these limitations, gutter systems offer benefits. They reduce heating costs per ground area and are generally easier to install than truss-to-truss systems.
Option 3: Truss-to-Truss System
Truss-to-truss systems use curtain panels that move from one truss to another. There are three common configurations.
1. Flat at gutter height
This setup is similar to the gutter system and helps minimise the volume of space that needs heating. Installation is relatively straightforward.
2. Slope-flat-slope
In this configuration, the curtain follows the roof slope partway up the truss before transitioning into a flat section. This design allows the system to fit over equipment mounted above the gutter and leaves space to hang baskets.
3. Slope-slope
The slope-slope system runs parallel from the gutter to the peak of the truss. It reduces the amount of cold air trapped above the curtain and provides greater clearance for equipment.
Both slope-flat-slope and slope-slope systems have some drawbacks. They take longer to install, leave more greenhouse volume above the curtain, and require more materials for moving and stationary edges. However, both designs still allow space for hanging baskets.
Cooling your greenhouse with thermal shade cloths can be a cost-effective way to regulate temperature and support consistent crop performance.
Related greenhouse climate topics
Shade cloths are just one part of managing greenhouse temperature and humidity. You may also find these guides useful:
If you’re managing a commercial greenhouse, understanding your growing environment is key.
Bluelab works with growers to measure and monitor the conditions that influence crop performance. This helps you make more confident decisions about how your greenhouse is running.
Contact Bluelab to discuss monitoring and measurement options for your commercial grow environment.
