The Improvement Plan of Natural Ventilation Performance Evaluation of Residential Buildings in Green Building Certification (G-SEED)

Purpose: G-SEED has had a significant impact on reducing carbon emissions and saving energy in the eco-friendly building sector. Additionally, it has contributed to improving indoor air quality by promoting the use of pollutant reduction materials. However, an analysis of formaldehyde and VOCs concentrations in 30 buildings that obtained G-SEED revealed that some VOC concentrations exceeded recommended levels, despite the use of materials emitting less than the TVOC standard. To address this issue, this study conducted a feasibility study on the appropriate ratio of natural ventilation performance suggested by G-SEED for ventilation windows, which can affect the reduction of indoor TVOC emissions. Method: Measurements and simulation analyses were carried out in three locations in certified buildings. In the measurement analysis, TVOC concentration characteristics were studied with windows and doors closed. During natural ventilation, there was a rapid decrease in concentration within 30 minutes. Based on these findings, a simulation of natural ventilation was conducted by applying a ratio of 11 ventilation windows per floor area. The results showed that when the ventilation window application rate was at least 6%, the TVOC concentration decreased to IAQ level 1 within 30 minutes. Result: Consequently, based on the measurement and simulation results, this study proposes an improvement plan to revise the ratio of windows in the natural ventilation performance category of residential buildings in the current G-SEED, lowering the minimum requirement from 8% to 6%.