Why EC Plug Fans Are a Smarter Alternative to Belt-Driven Forward Curved Fans in AHU Systems | Belmont Fan As HVAC system efficiency requirements continue to rise, facility managers and OEMs are rethinking their equipment choices—starting with the fan system inside the air handling unit (AHU). One of the biggest opportunities for energy savings and system optimization lies in replacing traditional belt-driven forward curved fans with modern EC plug fans. At Belmont Fan, we specialize in EC plug centrifugal fans, helping HVAC manufacturers and integrators worldwide move toward a quieter, more compact, and far more energy-efficient future.