# Appendix C Acoustics of Buildings¶

## Example C.1 Page no 427¶

In [20]:
#Given
s1=5000
a1=0.05
s2=8000
a2=0.03
s3=500
a3=0.025
s4=600
a4=0.3
s5=500
a5=4.2
v1=50
v2=80
v3=20

#Calculation
A1=s1*a1
A2=s2*a2
A3=s3*a3
A4=s4*a4
A5=s5*a5
A=A1+A2+A3+A4+A5
V=v1*v2*v3
T=(0.16*V)/A

#Result
print"(i) Reverbrating time with absorption coefficient 0.05 is",A1,"sq m"
print"(ii) Reverbrating time with absorption coefficient 0.03 is",A2,"sq m"
print"(iii) Reverbrating time with absorption coefficient 0.025 is",A3,"sq m"
print"(iv) Reverbrating time with absorption coefficient 0.3 is",A4,"sq m"
print"(v) Reverbrating time is",round(T,1),"Second"

(i) Reverbrating time with absorption coefficient 0.05 is 250.0 sq m
(ii) Reverbrating time with absorption coefficient 0.03 is 240.0 sq m
(iii) Reverbrating time with absorption coefficient 0.025 is 12.5 sq m
(iv) Reverbrating time with absorption coefficient 0.3 is 180.0 sq m
(v) Reverbrating time is 4.6 Second


## Example C.2 Page no 428¶

In [28]:
#Given
S1=220                             #m**2
S2=120
S3=120
T=460.0
a1=0.03
a2=0.06
a3=0.80
V=600                                #m**3

#Calculation
A=S1*a1+S2*a2+S3*a3
Av=A/T
T1=0.16*V/A

#Result
print"Average absorption coefficient is",round(Av,3)
print"Reverbration time is",round(T1,2),"Sec"

Average absorption coefficient is 0.239
Reverbration time is 0.87 Sec


## Example C.3 Page no 429¶

In [30]:
#Given
V=7000                                 #m**3
T=1.4                                  #sec

#Calculation
A=0.16*V/T

#Result
print"Total absorption is",A,"O.W.U"

Total absorption is 800.0 O.W.U


## Example C.4 Page no 429¶

In [37]:
#Given
a1=6                     #m
a2=4
a3=3
a=0.25

#Calculation
V=a1*a2*a3
S=((a1*a2)+(a2*a3)+(a3*a1))*a
T=0.16*V/S

#Result
print"Time of reverbration is",round(T,2),"Sec"

Time of reverbration is 0.85 Sec


## Example C.5 Page no 430¶

In [47]:
#Given
a1=0.03
s1=220
a2=0.80
s2=120
a3=0.06
s3=120
V=1200

#Calculation
a=(a1*s1+a2*s2+a3*s3)/(s1+s2+s3)
a1=a*(s1+s2+s3)
T=0.16*V/a1

#Result
print"Average sound absorption coefficient is", round(a,4)
print"Reverberation time is",round(T,2),"Second"

Average sound absorption coefficient is 0.2387
Reverberation time is 1.75 Second