APPLICATION OF BUILDING PHYSICS METHODS FOR NATURAL LIGHTING OF UNDERGROUND ROOMS OF EDUCATIONAL INSTITUTIONS

Abstract

Since the beginning of Russia’s full-scale invasion of Ukraine, the construction of underground public buildings has become a strategic priority for protecting civilians, particularly in frontline regions. For the first time in global practice, fully underground schools and kindergartens have been implemented as facilities capable of mitigating the effects of blast waves, fragmentation, and radiation hazards. However, the absence of natural daylight in such environments creates significant sanitary-hygienic, physiological, and psychological challenges, especially for children who remain underground for extended periods. Insufficient daylight negatively affects circadian rhythms, visual performance, emotional stability, and learning efficiency.

The purpose of this study is to develop practical recommendations for the integration of natural daylighting systems into underground educational buildings. The research methodology is based on a systems approach, theoretical analysis, review of international case studies, evaluation of Ukrainian regulatory documents, and examination of modern daylight transportation technologies, including light pipes, fiber-optic systems, heliostats, mirror light guides, and reflective light tunnels.

The paper presents a design proposal for an underground kindergarten in which daylight transportation is combined with the ventilation system into a unified engineering unit. Light-collecting elements are placed on separate reinforced concrete columns located outside the debris zone, ensuring system operability in case of structural damage. The design incorporates spherical collectors, reflective light guides with 90° rotation, protective dampers with automatic sealing, and transformer furniture for flexible spatial use.

The results demonstrate that transported natural lighting improves visual comfort, supports healthy biological rhythms, reduces dependence on artificial lighting, and enhances the psychological well-being of users in protected underground environments. The scientific novelty lies in the first comprehensive method for providing daylight in underground educational facilities in Ukraine under wartime conditions. The practical significance consists in the applicability of the proposed solutions for the design of protected schools, kindergartens, and hospitals, contributing to energy efficiency, environmental sustainability, and improved quality of life in underground architecture.