What Is an Artificial Sky and How Does It Work?

An artificial sky is a controlled lighting environment that recreates selected characteristics of natural daylight for study and testing. Architects, designers, researchers, and students can use these facilities to examine how daylight enters and spreads through buildings. By providing repeatable lighting conditions, the setup helps users study daylight performance and make informed decisions about building design.

What Is an Artificial Sky?

An artificial sky is a physical facility designed to simulate the luminance patterns of the sky under defined conditions. It typically uses electric light sources and specially designed surfaces or arrangements to distribute light across a testing area. Depending on the facility, the system may represent overcast or other specified sky conditions.

Architects and researchers commonly place scale building models inside the facility. This approach allows them to observe how building form, windows, openings, and interior layouts influence daylight within a space. The controlled environment also makes it possible to conduct consistent daylight studies across different design options.

How Does an Artificial Sky Work?

The system creates a defined sky lighting condition around a model or test area. Its components work together to produce, distribute, and measure light during a daylight study.

The main parts of the process include:

• Controlled Light Source: Electric lamps or other lighting equipment generate the light needed to simulate the selected sky condition.

• Light Distribution: Reflective, diffusing, or illuminated surfaces distribute light according to the required sky luminance pattern.

• Test Model Placement: A scale model is positioned within the testing area so light can enter through windows, skylights, and other openings.

• Light Measurement: Sensors such as illuminance meters record light levels at selected points within the model.

These steps provide measurable information about how daylight performs within a proposed or existing building design.

What Can an Artificial Sky Help Measure?

Daylight testing can provide useful information about the amount and distribution of light within interior spaces. Measurements can also support comparisons between different design choices.

Common factors studied during testing include:

• Indoor Illuminance: Sensors measure the amount of light reaching selected surfaces or locations inside a model.

• Daylight Distribution: Measurements show how evenly daylight reaches different parts of an interior space.

• Window and Opening Performance: Tests show how the size, position, and design of openings influence indoor daylight.

• Shading Effects: Models can demonstrate how shading devices affect the amount and pattern of daylight entering a space.

These measurements help design teams understand daylight behavior and compare potential building solutions using consistent test conditions.

Where Are Artificial Skies Used?

Artificial sky facilities are mainly used in architecture, building science, daylight research, and education. Design teams can use them to study daylight during different stages of building development and compare design options under repeatable lighting conditions.

Universities and research institutions also use these facilities for experiments and teaching. Students can observe daylight principles through physical models, while researchers can collect measurements for studies related to building form, openings, shading, and indoor lighting.

Conclusion

An artificial sky provides a controlled way to recreate defined daylight conditions and study their effects on buildings. By combining controlled lighting, light distribution, physical models, and measurement tools, it helps users examine indoor daylight performance. Its use in design, research, and education supports informed decisions about windows, shading, building form, and interior daylight conditions.