Current Acoustic Condition
Use Case and Reference Standard
The multipurpose room of Raplab (HIL B61), has the primary use case of lecture and workspace.
According to the SIA 181/1 standard, this use case is categorized under 1b Speaking/Lecturing or 1c Teaching/Communication. Take 1c as reference standard as it requires a smaller T_soll.
The target T_soll of 1c is then:
0.26 lg(238 m3/m3) – 0.14 = 0.48s
Sound Frequency for Speaking
Approximate from 250 Hz – 4 kHz
Reverberation Estimation
- Numerical Estimation
For the room with volume of 238 m3, consider the sound frequency of 250 Hz – 4 kHz.
With the material information, the existing RT_60 is in average 1.8s, far from the target value.
Empirical Estimation
From the estimation, the room with its current setting as workspace has a RT60 value of 0.86s, which does not meet the goal (T_soll) of 0.4s.
Summary of Reverberation Estimation
The numerical estimation reaches its limit due to the unknown material properties / quantities (eg. clothes, models, shelf…)
Nonetheless the current RT is far from meeting the T_soll value, intervention needs to be implemented.
Proposed Acoustic Treatment
From the existing condition analysis, the space has very limited amount of sound absorbing material, which shortens RT.
Targeting specifically in the frequency band between 250-4000 Hz, the following sound absorbing materials are recommended.
Ceiling
Cover concrete ceiling surface with “Wood tongue-and-groove planks”
Source: https://www.akouo-acoustics.com/woodline-groove
Wall
Replace current side reflectors with “Pattern Fiberglass”
Source: https://auralaid.com/fiberglass-acoustic-panels-for-noise-control-in-singapore-workspaces/
Floor
Cover floor surface with “carpet”
Summary
The intervention drastically improved the reverberation time in this room.
