Comparative analysis of natural, mechanical and hybrid ventilation systems in public buildings

Abstract

The conflict between indoor air quality demands and energy-saving targets in public buildings has intensified as the requirements of SP 60.13330.2020 and SP 50.13330.2024 have tightened. Design decisions oscillate between traditional gravity-driven natural schemes, full mechanical supply-exhaust units with heat recovery, and hybrid variable-mode systems; unambiguous selection criteria coordinated across climatic zones and building types have not been established in technical literature. The aim of this work is to compare the three schemes against a set of technical, energy and economic indicators for typical public buildings. Three model objects – an administrative block of 1500 m², an educational building of 5200 m² and a retail facility of 9800 m² – were used as the design basis, with reference to the climatic conditions of Vladivostok, Moscow and Yakutsk. Comparative-analytical and calculation-normative methods were applied; heat transfer coefficients and specific air consumption rates were calculated according to SP 60.13330.2020. The hybrid scheme yields an air change rate of 1.8-4.5 h⁻¹ at specific energy consumption of 12.7 ± 0.4 kWh/m² per year – 31,2% lower than the mechanical supply-exhaust system and 18,4% higher than the natural scheme with corrective devices; for climatic zones with mean annual temperature below −2° C the advantage of the mechanical variant in terms of microclimate provision becomes decisive. The findings are applicable when developing design strategies for highly-occupied public buildings and when revising departmental recommendations for ventilation scheme selection.