York YUHC 18, Service Manual, Page: 8 / 49

Part3. Noise level
CONCEALED DUCT TYPE
Microphone
1.0m
Duct
18,000~24,000 btu/h 30,000~36,000 btu/h
Octave band center frequency
£ ¨
Hz
£ ©
Sou
nd pr
es
su
re
le
ve
l
d
B
£¨
0
d
B=
0.
000
2
¦Ì
bar
£©
Audibility limits of
continuous white
sound
Audibility limits of
continuous white
sound
So
und pre
ssure
le
ve
l dB
£¨
0dB
=0.
0
0
0
2
¦Ì
ba
r
£©
Octave band center frequency
£ ¨
Hz
£ ©
48,000 btu/h 60,000btu/h
Audibility limits of
continuous white
sound
Sou
nd pressur
e level dB
£¨
0dB=0.00
02
¦Ì
bar
£©
Octave band center frequency
£ ¨
Hz
£ ©
Audibility limits of
continuous white
sound
S
ound
p
ressure level d
B
£¨
0dB=
0
.0
002
¦Ì
bar
£©
Octave band center frequency
£ ¨
Hz
£ ©