INTEGRATED ROOM LIGHTING: A PATH TO REDUCING ENERGY CONSUMPTION IN LED LIGHTING SYSTEMS

In addition to ensuring visual functions, light exerts a biological effect on humans, known as non-image-forming (NIF) response to light. Such NIF responses to light stimuli support the normal physiological state of humans during daytime. The new international standard ISO/CIE 8995-1:2025 "Light and lighting - Lighting of workplaces" specifies requirements for workplace lighting in rooms, including recommendations for circadian stimulation at appropriate times of day. It notes that achieving the recommended values for circadian effectiveness requires higher illumination levels than those established by existing standards for visual functions, negatively impacting lighting energy efficiency. This study aims to analyze ways of reducing energy consumption of lighting systems and experimentally investigate methods for ensuring the required level of integrated lighting without exceeding energy consumption limits specified in DBN V.2.5-28:2018 "Natural and Artificial Lighting". The work provides a description of the test room used for experiments, outlines research methods, and analyzes various approaches for reducing energy consumption, including optimization of LED luminaires characteristics, effective use of daylight, and enhancing reflectivity of interior surfaces. It is demonstrated that using daylight, employing LED luminaires with luminous efficacy no lower than 100 lm/W and correlated color temperature (CCT) of 6000-6500 K, along with ceiling and wall surfaces having a reflectance coefficient of 0.8, can ensure melanopic illumination levels compliant with ISO/CIE 8995-1:2025 requirements, without exceeding specific installed power norms (W/m²) as stipulated by the DBN V.2.5-28:2018 guidelines. Conclusions and recommendations are formulated based on the obtained results.