Greenheck Fan Mixed Flow Fans Belt and Direct Drive QEI-L - Manual (Page 8)

8
Optional Features
The Sure-Aire™ flow monitoring system measures fan
flow within a 3% accuracy. Unlike traditional flow probes
mounted in the fan venturi that create a system effect
hindering fan performance, Sure-Aire™ does not interfere
with airflow and will not impact the fan’s air or sound
performance. This option is available on all mixed flow fan
models and ships completely assembled from our factory.
An electronics package with pressure transmitter and
digital read out is available with the Sure-Aire™ system. The
electronic kits are available for 50 or 60 Hz power supplies
and provide a 4-20 mA output that can be tied into the
building’s automation system.
Sound Vault Housing - Radiated Sound Enclosure
The sound vault housing is an excellent product for fans that will be positioned adjacent to an occupied work
space or in sound critical applications. It locks in radiated sound from the fan casing, motor and drives, and
minimizes vibration transmission. Standard construction includes an acoustically lined housing, integral spring
isolators, and internal flexible connections at the fan’s inlet and outlet to effectively isolate the fan from the
system. Vertical or horizontal mounting configurations are available.
Why use a Sound Vault?
• Sound power attenuation levels determined by
sound intensity tests on actual units
• Ships fully assembled with fan
• Internal isolation to limit breakout noise
• Access panels for inspection of fan and motor
• Bearing lubrication lines extended to outside of
enclosure
• Formed mounting rails with prepunched holes
for easy installation
• Available on both QEI-I and QEID through
size 27 fans
This table lists the radiated sound
reductions from total sound power
levels for each octave band with
the sound vault housing.
Sound Sensitive Areas
Sure-Aire™
Center Frequencies [Hz] 63 125 250 500 1000 2000 4000 8000
Attenuation Value (dB) 13 20 25 31 34 35 36 36