Evaluating Emerging Spectral Lighting Software: Comparing Measurements of Light Spectrum and Derived Metrics in a One-Room Laboratory Environment with Simulation Results

ABSTRACT

The goal of this study was to evaluate the use of new spectral simulation tool, Adaptive Lighting for Alertness (ALFA), by comparing software-predicted values of spectral irradiance, illuminance, and equivalent melanopic lux (EML) to corresponding measurements captured in a laboratory environment with light-emitting diode (LED) luminaires. Four lighting conditions were considered by varying the correlated color temperature (CCT) of the LED luminaires. Meter measurements of space geometry, spectral reflectance distribution (SRDs) of materials, and spectral power distribution of luminaires were used as input to the simulation. Simulated spectral irradiance values between 400 and 700 nm were generally within 10% of measured values, with many spectral bands having less than 5% error. Larger mean absolute percent error (MAPE) was observed for the mixed lighting conditions for bands between 420 and 490 nm, which subsequently influenced calculated EML values. Compared to horizontal measurements, vertical measurements were particularly susceptible to additional error through the measurement procedure and measurement equipment.

KEYWORDS:

• Lighting simulations
• software validation
• spectral simulations
• solid state lighting

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was completed as part of the 2020 BENEFIT FOA, supported by the U.S. Department of Energy’s Solid-State Lighting Program, part of the Building Technologies Office within the Office of Energy Efficiency and Renewable Energy (EERE).