Greenheck Fan Centrifugal Ceiling and Cabinet Exhaust Fans CSP - Manual (Page 14)

14
Sound Data
The sound data shown in this catalog has been
presented to aid the system designer in selecting a
fan which will meet the desired sound criteria. Sone
levels have been included on the performance pages
to provide a means of quickly evaluating the relative
loudness of a fan selection.
What is a sone?
Sones are an internationally recognized unit of
loudness. In practical terms, the loudness of one sone is
equivalent to the sound of a quiet refrigerator measured
from five feet away in an acoustically average room.
A sone is a single number rating, which indicates the
inlet noise derived from the eight audible octave bands.
Sones are a linear measurement of sound level. For
example, a sound level of 10 sones is twice as loud
as 5 sones.
Can radiated noise increase the
sound levels?
Radiated noise from fan housings can cause
unacceptable sound levels, on any brand of fan. The
size of these fans allows them to be placed in areas
where this noise will be transmitted to the conditioned
space through walls or ceilings. Where possible,
cabinet fans should be located in remote parts of the
ventilation system.
When should a SP or CSP fan be used?
Model SP and CSP fans are designed for the lowest
possible sound levels. Forward-curved wheels,
Model CFM WG FRPM Sones
SP-A410 405 1/8 1000 3.0
CSP-A410 403 1/8 1000 1.5
*Sone value with insulated inlet duct.
Things to know when
sound is critical
The compact size of the SP and CSP fans provides
the system designer greater flexibility in locating these
fans for lowest sound levels. In critical sound areas,
insulated ductwork, flexible duct connections, or
placing the fan in a remote section of the ductwork
(away from the critical area) offers the best means of
meeting desired sound levels.
Remote mounted
model CSP with
vibration isolators
and insulated
ductwork provides
the quietest
installation.
Model SP mounted directly
overhead may be too
loud for sound critical
applications.
Fiberglass
insulated housings and vibration isolators between
the motor and housing contribute to quiet, efficient
operation. Applied and installed as recommended,
SP and CSP sound levels will fall well within the
ranges shown in the Suggested Limits for Room
Loudness chart. For applications where sound levels
are critical, a remote mounted CSP with ductboard is
recommended. Placement of SP and CSP fans should
take into account the desired sound level at the
location of the listener.
Suggested Limits for Room Loudness
Sones DBA
1.3-4 32-48 Private homes (rural and suburban)
1.7-5 36-51 Conference rooms
2-6 38-54 Hotel rooms, libraries, movie theatres, executive offices
2.5-8 41-58 Schools and classrooms, hospital wards and operating rooms
3-9 44-60 Court rooms, museums, apartment houses, private homes (urban)
4-2 48-64 Restaurants, lobbies, general open offices, banks
5-15 51-67 Corridors and halls, cocktail lounges, washrooms and toilets
7-21 56-72 Hotel kitchens and laundries, supermarkets
Reprinted from AMCA Publication 302 (Application of Sone Ratings for Non-ducted
Air Moving Devices, with room—sone—dBA correlations) with the written permission
from the AMCA International, Inc., 30 West University Drive, Arlington Heights,
IL 60004-1893.
NOTE: Values above are for room loudness and are not sound ratings. Room loudness
is the resulting level in a conditioned space after the acoustical qualities of the room
have been accounted for.
When room sound levels are
critical, such as in executive
offices, conference rooms, hospital
operating rooms, and school study
areas, a CSP fan is the best choice.
Shown here is a comparison of SP
and CSP fans of the same size,
with equal performance in typical
installations. The CSP shows lower
sone values.