No abstract

Heating of large-cubage buildings accounts for significant share of energy consumption. The radiant heating system using gas heaters is a common solution for large-cubage halls and is considered to be energy efficient. There is a possibility of additional heat energy recovery from the flue gases of gas radiant heaters because new solutions were introduced to the market. Furthermore heat recovery consists the most promising solution and develop during the recent years rapidly. On the other hand, few works have been dedicated to heat recovery from exhaust gas but none of them consider exhaust gas from radiant heaters. Exhaust gas temperature depends on the type and efficiency of the gas heater. The selection of both the type of radiant heaters and the heat recovery system requires many factors to be taken into account. This study consider possibilities for application of different heat exchangers in exhaust gases system of gas radiant heaters. The authors propose to classify exhaust gas heat recovery systems in dependence on intermediary medium: water/air, gas heaters type: ceramic/tube and number (single/group) and their mounting location.

This paper demonstrates the need and potential for using waste heat recovery (WHR) systems from infrared gas radiant heaters, which are typical heat sources in large halls, due to the increasing energy-saving requirements for buildings in the EU and the powerful and wide-spread development of the e-commerce market. The types of gas radiant heaters are discussed and the classification of WHR systems from these devices is performed. The article also presents for the first time our innovative solution, not yet available on the market, for the recovery of heat from the exhaust gases of ceramic infrared heaters. The energy analysis for an industrial hall shows that this solution allows for environmental benefits at different levels, depending on the gas infrared heater efficiency, by reducing the amount of fuel and emissions for domestic hot water (DHW) preparation (36.8%, 15.4% and 5.4%, respectively, in the case of low-, standard- and high-efficiency infrared heaters). These reductions, considering both DHW preparation and hall heating, are 16.1%, 7.6% and 3.0%, respectively. The key conclusion is that the innovative solution can spectacularly improve the environmental effect and achieve the highest level of fuel savings in existing buildings that are heated with radiant heaters with the lowest radiant efficiency.