Time-stepped exergy analysis, enviromental and economic evaluation of a new designed natural ventilation system

Abstract

This study investigates a new stack-type natural ventilation system (NVS) designed for small and medium-scaled industrial buildings. The NVS was designed and constructed for the disposal of the welding gases to obtain suitable working conditions from the thermal comfort point of view. The NVS system was analyzed by time stepped exergy analysis based on experimental data observed for a yearlong measurement. The experimental set-up was established to determine the ventilation throughout the wind speed measurements, temperature, and relative humidity measurements. Besides, the NVS was economically evaluated by the net present value (NPV) method. The exergy efficiency of the system was recorded ranging between 65 and 95% depending on the external conditions such as wind speed and outdoor temperature. With annual ventilation of 6,850.80 m3/h, it was determined that an annual saving of 12,092.20 m3 of natural gas, 1045.11 tones of CO2 emission, and 0.0345 GWh electricity was available. The system was found investable with an NPV of 18,576.61 $ for a lifetime of 20 years.