Plenum Fans are designed specifically for application in pressurized plenums found in industrial and commercial air-handling systems. The unhoused, compact design combined with the choice of two AcoustaFoil® wheels provides the utmost in quiet and efficient operation.
• Two wheel choices: High-efficiency AcoustaFoil wheels, Sizes 12” – 73”. Ultra-quiet AcoustaFoil-Q wheels for sound-sensitive applications, Sizes 18” – 66”.
• Capacities to 160,000 CFM.
• Pressures to 12” WG.
• Aerodynamic, spun inlet cone.
• Choice of four horizontal arrangements:
Arrangement 1 —Sizes 12” to 15”
Arrangement 3 —Sizes 16” to 73”
Arrangement 3-P—Sizes 16” to 40”
Arrangement 4 —Sizes 12” to 60”
• Arrangement 3-V for vertical mounting in Sizes 16” to 73”.
• Designed and tested to eliminate all natural frequencies in the operating range.
• Temperatures to 120°F.
• Formed structures for rigidity and improved fit.
• Bearings selected for average L10 life of 40,000 hours at maximum speeds.
• Lifting eyes are standard.
• Wheels are dynamically balanced and fans are checked at the specified operating speed.
Unhoused Plenum Fans were developed in response to the continuing push for greater system value and application flexibility in air-handler systems. For systems utilizing pressurized plenums, these fans provide the airflows and pressures of conventional housed fan designs but in compact, more economical configurations. The result is reduced size and weight of air-handler cabinetry with maximum application flexibility. System air is supplied or returned to the air handler from virtually any direction with a minimum of ductwork. Plenum Fans offer system manufacturers the utmost in choice of sizes and configurations.
A traditional airfoli plenum fan wheel ensures:
Completely stable pressure curve from wide open to closed-off…ideal for variable air volume systems.
Horsepower reaches a peak and then decreases as flow increases… allows calculation of the maximum brake horsepower at a given fan speed so a motor can be selected that will not overload if system pressure changes.
CHOICE OF TWO ACOUSTAFOIL WHEEL DESIGNS:
TRADIDIONAL AIRFOIL FAN WHEEL
EFFICIENCY: The mechanical efficiency curve offers a broad selection range with little horsepower variation.
SOUND: The superior efficiency of the AcoustaFoil wheel provides a low sound level over a wide performance range.
ULTRA-QUIET ACOUSTAFOIL-Q WHEEL
For sound-sensitive applications. After years of acoustical research and testing in two accredited sound testing laboratories, our time-tested AcoustaFoil Fan Wheel technology is quietly taken to the next level.
STABLE AND EFFICIENT PERFORMANCE: Same efficiency and horsepower characteristics as the traditional AcoustaFoil wheel.
NEW SELECTIONS: Unique performance offers alternative selections to the traditional AcoustaFoil wheel.
SOUND: Acoustically tuned wheel and cone reduces sound power levels in the lower octave bands, flattens overall sound profile, and also minimizes fan blade pass frequency turbulence.
Both airfoil Plenum Fan wheels are designed to operate efficiently at less than maximum design airflow. The high efficiency and inherent stability of the AcoustaFoil wheel is particularly well-suited to variable airflow systems. The AcoustaFoil wheel design ensures not only maximum operating efficiency at design CFM but also at reduced airflow regardless of the control method applied. This higher efficiency allows quieter operation throughout the modulation range.
INLET-VANE DAMPER CONTROL
Inlet-vane dampers affect the fan’s output by spinning the air in the direction of wheel rotation. With this prespin, the wheel cannot develop its full output, yielding a reduced CFM at reduced horsepower. Each damper setting creates new pressure and horsepower curves. With inlet-vane dampers, reduced airflow always results in reduced horsepower.
VARIABLE FREQUENCY MOTOR SPEED CONTROL
Variable frequency motor speed controllers provide energy savings by directly controlling fan speed. From the fan laws, CFM varies directly with the change in fan speed and horsepower varies by the change in fan speed 20% reduction in fan speed yields a 20% reduction in airflow and a 50% reduction in BHP. Controllers must have lockouts to prevent operation beyond the maximum safe speed of the fan.