FANWALL TECHNOLOGY has revolutionized air movement in the HVAC industry. After many years, most of the original naysayers have adopted some form of fan array technology. While these competing systems share many of the common elements of the original FANWALL® system, continuous improvement and innovation from Nortek Air Solutions has pushed the technology with many exciting, energy efficient and interesting new features.
By now the main key benefits are well known:
However there are a number of features that are often overlooked when evaluating a standard fan array against FANWALL TECHNOLOGY.
FANWALL fans are designed specifically for a fan cube environment to achieve the industry’s highest efficiency in their size range. More horsepower increments to choose from allow FANWALL to more exactly match required brake horsepower and reduce the connected load, wire sizing, transformer and switchgear costs for the building.
One of the hallmarks of FANWALL TECHNOLOGY is the use of smaller motor sizes, typically less than 10 horsepower. This design principle keeps the fan and motor components to a manageable size for service, reduces residual imbalance, reduces system effect and lowers the fan acoustical signature.
Incremental horsepower motors support this design principle by allowing expanded motor selections within a given horsepower range versus what is traditionally available from motor manufacturers (see chart).
Expanded horsepower motor selections would allow a designer to select a 5.5 horsepower motor—much closer to the design fan brake horsepower—and reduce the connected load, wiring and switchgear costs for the building.
Availability of incremental horsepower motors is the same as standard motor selections because they are a standard product for motor manufacturers. They are NEMA motors that have been re-rated, nameplated and fully warranted based on their use in a FANWALL cube.
What makes this possible is the unique airflow pattern in a FANWALL cube, and the Coplanar Silencer® that encases that airflow while providing acoustic benefits. These serve to force more air over the motor fins for cooling, which is important to improving the capacity of a motor. In regular open plenum fan type arrangements, airflow is not directed over a standard motor, so the added efficiency is not realized.
FANWALL TECHNOLOGY automatically models and implements the most efficient system configuration to meet airflow requirements by varying the speed and number of enabled fans and motors at any given point in the operating range.
Improved system optimization controls for FANWALL systems optimize the ability to automatically reconfigure the number of active fans while controlling the speed of enabled fans to optimize efficiency over the range of system loading of an air handler. The improved controls include new algorithms, a stand alone or BAS interface, an individual VFD for each fan/motor combination and the model FBD backdraft damper with near zero system effect.
The controller provides a means to indicate fan and motor status, operating mode, system flow rate and fan total static pressure, as well as connected and required horsepower at the current system flow and pressure conditions. This information can be displayed on a stand alone interface at the control panel or remotely through a BAS interface.
A dedicated VFD for each fan and motor combination provides the electrical means for on/off fan and motor speed control. In addition to refining control, the individual VFDs eliminate the need for a bypass VFD, and reduce wiring requirements and the overall size of the control panel required for a FANWALL system.
An integral part of system optimization controls for FANWALL systems is the FBD backdraft damper. Disabling a fan or fans in a FANWALL system requires a means to prevent backflow of air through the idled cube. Traditional dampers, while capable of performing this function, were not designed for a fan array application and impose unwanted airflow and static pressure losses (system effect), in addition to adding to acoustic and leakage concerns.
The patent pending FBD backdraft damper has a revolutionary new blade profile that actually improves flow characteristics. In testing, this revolutionary new damper has been shown to impose near zero system effect (see graph) with reduced acoustic impact.
In addition, the FBD backdraft damper has a low leakage rate of only 2 cfm/sq. ft. at 1-inch of static pressure. This far exceeds requirements for a 1A class rating for control dampers and is nearly nine times less than the industry standard backdraft damper, which has a reported leakage of 17.5 cfm/sq. ft. at the same static pressure.
Visit the Nortek Air Solutions website to learn more about FANWALL TECHNOLOGY and download literature.
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