Ocheretianko M. Energy efficient space heating by combined use of electric infrared emitters and water heaters

Thesis for a Doctor of Philosophy degree by specialty 05.23.03 ”Ventilation, lighting, heat and gas supply” – Kyiv National University of Construction and Architecture, Kyiv, 2021. Thesis devoted to finding solution for actual scientific and technical problem – researching dynamic formation of a comfortable indoor hydrothermal environment and increasing buildings energy efficiency by means of applying combined heating system, which consist of electric infrared heaters and water heating devices. Based on the conducted energy and exergy comparative analysis for heating systems efficiency with different sources of heat and energy supply promising ways of creating combined radiative-convective systems were shown. Mathematical model analysis for indoor hydrothermal environment which occurs in radiative-convective heating system is carried out and the analytical solution of differential equations describing heat-mass transfer processes in “heating devices - humid air – enclosure surfaces” system is obtained. Conducted experimental studies for dynamic indoor hydrothermal environment formation for premises heated with electric infrared heaters and water heating devices. Influence of air moisture content on internal surfaces irradiation and it’s corresponding effect on indoor thermal comfort parameters has been investigated. Design improvement recommendations for electric infrared heaters were given. Recommendations aimed to make operation of electric infrared heaters more efficient in combined radiative-convective heating systems. Engineering calculation methodology for combined radiative-convective heating system has been developed. A technical and economic analysis for heating systems has been carried out. Based on it’s results were determined conditions under which it is advisable to use a combined radiative-convective heating system.