INSUL is a
program for predicting the sound insulation of walls, floors, ceilings and windows. It is
based on simple theoretical models that only require easily obtainable construction
information. The program can makereasonableestimatesofthe Transmission Loss (TL) and Weighted Sound Reduction
Index (STC) for use in noise transfer calculations.
Test data can be entered to permit easy comparison
with predictions. INSUL takes account of finite size effects,
which are very important when predicting small samples such as windows and also for normal
elements at low frequencies.
Like any prediction tool INSUL is not a
substitute for measurement.However,
comparisons with test data indicate that INSUL reliably
predicts STC values to within 3dB for most constructions.
Screen Display: Staggered Wall Construction
Screen Display: Ceiling Construction
INSUL can be used to quickly evaluate new materials and systems, or
to investigate the effects of changes to existing designs.It models materials using the simple mass law and coincidence frequency approach
and models more complex partitions using work by Sharp, Cremer and others.It can predict the effect of installing an
acoustic blanket in the stud cavity.It has
evolved over several versions into a very easy to use tool that takes advantage of the
Windows™ environment, and has been refined by continued comparison with laboratory
tests to provide acceptable accuracy for a wide range of constructions.
INSUL will
greatly enhance the ability of acoustic consultants and product manufacturers to quickly
and confidently specify constructions in order to achieve a desired airborne sound
insulation
Leakage Calculation
Composite Transmission Loss Calculation
Insul includes the ability to predict the effect of leakage. This is
especially useful for predicting the sound insulation of doors and windows
which are notoriously difficult to seal perfectly. Insul uses the theory
published by Gomperts (The Sound Transmission of Circular and Slit Shaped
Apertures in Walls (Gomperts and Kihlman 1967 Acustica Vol 18)) to firstly
predict the transmission loss of thin slits and then the combined
transmission loss of the slit and the partition.
A composite transmission
loss calculator allows to compute the total Transmission Loss for a
composite Wall Assembly. This software feature can either use INSUL
data or the user can enter own data. The calculation works with either 1/3
or 1/1 Octave data.
