Modelling & Testing Results

Performance of different windows

From the early days of MACH Acoustics, we have attempted to establish the performance of windows, as well as investigating methods of enhancing the performance of vented facades. Originally, MACH Acoustics used scaled models, however computational methods have improved, and our research pot has grown, allowing us to now investigate the acoustic performance of open windows by means of analytical models.

The illustrations below compare propagation of sound through four types of windows. These illustrations clearly show the benefits of using such modelling.

Note that this modelling has been referenced against Napier University’s data, as well as test data measured at the Univeristy of Bath Hive (see Chapter 3).

Comparative Results Modelling

The graph below shows the result of combining the overall frequency response of this window and plotting the Rw value for the sash window over an open area.

The results of the Finite Element Modelling and Finite Time Difference Modelling shows a strong correlation with the data provided by Napier University and the results measured on site.

Results – Sash Window – Frequency and Opening

This video illustrates the sound reduction of a sash window being opened to different amounts, for the frequency of 1KHz.

Results - Angle of Incidence

These results show the effect of angle of incidence, upon the sound reduction of open windows.

Forms of Noise Control

Forms of Noise Control text

Modelling & Testing Results