Fans are generally classified as centrifugal, axial, mixed, or cross-flow, according to the direction of airflow through the impeller. A fan provides airflow and overcomes system resistance by increasing the total energy of the airstream. The rate at which energy is added to the airstream is air power, and it is the product of the airflow rate and the fan total pressure rise. Fan total efficiency is the ratio of the delivered air power to the shaft power supplied to the fan – or, output over input. The higher a fan’s efficiency, the more output it delivers per unit power input, and the less energy it consumes to deliver the same performance compared to a less efficient fan.
Energy reductions can be realized by requiring fans to meet a minimum energy efficiency. The Fan Efficiency Grade (FEG) is a new energy metric that recognizes the relationship between the impeller diameter and peak total efficiency. FEG is defined by ANSI/AMCA 205-12 Energy Classification for Fans, and ISO 12759 Fans- Efficiency Classification for Fans. The FEG is based on peak total efficiency and is a measure of the aerodynamic quality of the fan. Addendum U to ASHRAE 90.1 sets the minimum FEG at 67 on all fans, except those under 5 HP, emergency only fans, and power roof ventilators.
One of the most exciting innovation in air handling is to use a multiple fan array to move air versus traditional single or dual fans. Unlike other fan arrays available today, a FANWALL system is more than off-the-shelf fans and motors arranged in an array. It incorporates FANWALL TECHNOLOGY—innovated and manufactured specifically for fan array systems—to create an integrated system of state-of-the-art fans, motors, cabinetry, controls, and accessories. These components have been successfully blended to match new construction and retrofit application requirements, while providing the benefits of redundancy, quiet and vibration-free operation, optimized energy efficiency from design minimum to maximum flow, and low cost maintenance and service.
Our Fan System providers include:
- M.K. Plastics
- FANWALL technology from the CES Group
For additional information, click here.