introduction
Xiongqian makes perforated sheet and perforated metal mesh. We started making these products in 2012. Building shading is getting smarter. A perforated sheet is not just a metal panel with holes. Architects now use parametric design. Parametric design lets architects control the hole type of every panel. It also controls the angle. This balances shading, daylight, and airflow. Today, I share our manufacturing experience. I explain these three core parameters.
Why Parametric Design Matters
Traditional perforated shading is simple. The factory makes only one open area. The client uses it on the whole facade. But this is not smart. Different facades get different sun intensity. West walls get harsh sun. North walls get soft light. Parametric design adjusts the hole type and angle. It adjusts based on the specific location. This makes the building more energy-efficient.
ArchDaily reported on a project in Türkiye in 2025. It was a solar power plant control building. Kasso supplied about 7,200 stainless steel perforated sheet panels. These panels had four different perforation densities. These panels controlled daylight. They also moderated views. This is parametric design in action.
Hole Type and Open Area
The hole type sets the base performance. Round holes are the most common. Square, slotted, and hexagonal holes also have uses.
Open area is the key number. It is the ratio of hole area to total panel area. A lower open area gives better shading. But it also gives less daylight.
MDPI published a study in 2026. The study found that open area is the most influential parameter. Across all orientations, a 20% open area resulted in the lowest energy consumption. This ratio limits direct solar penetration. It also keeps enough diffuse daylight.
But the open area is not fixed. The best value changes with climate. The study noted that in hot arid Doha, 30% open area achieved up to 45% energy savings. In hot humid Lahore, 50% open area performed better. The larger airflow offset the high humidity.
Hole type also matters. Round holes give uniform shading. They act the same at different angles. Slotted or louver holes give stronger shading at specific angles. Parametric design can mix hole types. This achieves a specific result.
Shading Panel Angle
Angle is the most flexible tool. Shading panels can be horizontal. They can be vertical. The panel itself can be tilted. It can also rotate like a louver.
A study looked at a south-facing glass facade in Novi Sad, Serbia. The study showed that parametric perforated brise-soleils reduce solar radiation by up to 90%.
The study also found a specific optimal combination. For a south facade, it is four panels, a 28° inclination, circular holes (radius 0.5), and a density of 0.39. This gave the best shading.
Why is angle so important? It changes the “effective path” of sunlight. Sunlight passes straight through a normal hole. Sunlight hits at an angle. The panel thickness blocks part of the hole. This effectively reduces the open area. The WINDOW software technical documentation from LBNL provides formulas. The formulas are for circular hole transmittance. They show transmittance drops as the incidence angle increases. This means a tilted panel gives stronger shading at low sun angles. Low sun angles happen in the morning and evening.
Shading Coefficient (SC)
The shading coefficient measures how well a device blocks solar heat. A lower value means better shading.
The shading coefficient depends on two main factors. These factors are open area and installation angle.
Open area is the most direct factor. A panel with 20% open area has a base shading coefficient of around 0.2. But the actual value is affected by angle.
The angle effect is complex. Horizontal panels shade high-angle sun well. High-angle sun happens at noon. Vertical panels shade low-angle sun well. Low-angle sun happens on east and west facades. Parametric design optimizes the panel angle. It optimizes for the sun path.
ScienceDirect published a paper in 2014. The paper says metal screens depend on three things. These things are shading geometry, latitude, and orientation. The study used parametric analysis. It evaluated grids with different spacing. It evaluated the annual shading performance.
How the Three Parameters Work Together
These three parameters are not isolated. Parametric design optimizes them together.
| Parameter | Main Impact | Higher Value | Lower Value |
|---|---|---|---|
| Open Area | Base balance of daylight and shading | More daylight, weaker shading, higher energy use | Less daylight, stronger shading, may be too dark |
| Angle (Tilt) | Response to different sun heights | Stronger shading at specific angles, weaker at others | Uniform shading, less targeted |
| Shading Coefficient (SC) | Overall thermal performance metric | Less heat blocked, higher cooling load | More heat blocked, but may sacrifice daylight |
Here is a practical design workflow. First, the designer sets the target shading coefficient. Then, the designer chooses a base open area. They choose based on local climate. Dry climates use 20-30%. Humid climates use around 50%. Next, the designer uses parametric software. They use software like Grasshopper. They simulate actual shading at different angles. Finally, the designer generates the hole distribution map. The factory manufactures the product.
FAQ
What open area is best for a perforated shading panel?
There is no fixed answer. For hot dry climates, 20%-30% is suggested. For humid climates, 40%-50% is better. Parametric design can fine-tune this.
Does hole type have a big effect on shading?
It has an effect. But it is less than open area and angle. Round holes give uniform performance. Slotted and louver holes are stronger in specific directions. Parametric design can mix hole types.
What shading coefficient can be achieved?
A 20% open area with the right angle can achieve 0.15-0.25. But this requires simulation for each project.
What software is used for parametric design?
Rhinoceros with Grasshopper is common. Ladybug is used for solar analysis. Studies also use Galapagos for optimization.
Where can I find reliable perforated metal sheet suppliers?
Look for a manufacturer with parametric design capability. They can precisely control each panel. Feel free to ask.
Conclusion
Parametric design for perforated sheet shading comes down to three variables. These variables are hole type (open area), angle, and shading coefficient. Open area sets the base performance. Angle provides dynamic adjustment. The shading coefficient is the final measure. Parametric tools let architects find the optimal combination.
If you are planning a building shading project, send us the facade orientation. Send us the solar data. Xiongqian‘s engineering team will help you evaluate the open area. We will also help with the hole type. We can provide samples for real-world testing. Contact us if you need reliable perforated metal sheet suppliers.
