Sustainable building design requires the application of natural ventilation,
which has three prerequisites – a comfortable outdoor air temperature
(20–25°C), unpolluted outdoor air and a low-noise environment (under
55 dBA). There are many locations where the first two prerequisites are
met, but the environmental noise makes applying natural ventilation
challenging. This research developed an auxiliary noise-reducing vent for
windows (NRVW) that allows daylight and outdoor air to enter the room
while reducing the penetration of outdoor noise. As an auxiliary, the
NRVW is intended to be integrated into any (double) glazed windows
with a sound transmission class (STC) above 25 dBA. The research used
physical model experiments to measure the NRVW’s STC and outdoor–
indoor transmission class (OITC). Digital model simulation was used to
measure the NRVW’s ventilation performance. It was found that NRVW
has a rating of STC 18 and OITC 16, and it generates indoor air velocity
of 0.015–0.086 m/s in the occupants’ zone for an outdoor wind speed of
1–5 m/s. Modification of the room interior increases the indoor air
velocity to 0.147 m/s. Computer simulation also demonstrated that, with
an occupant inside the room, an outdoor air temperature of 25°C and
outdoor wind speed of 1–5 m/s maintained the indoor air temperature
at 25.309–25.258°C, indicating that the resulting airflow could keep the
indoor air temperature low. Although the NRVW was originally
developed for warm–humid climate conditions, it is also applicable for
other climates if the required outdoor conditions are met.