Centrifugal Cabinet Fans, including Forward-Curved and Backward-Curved Centrifugal Cabinet Fans:
Forward-Curved Centrifugal Cabinet Fans: These fans operate at a slower speed and are typically suited for applications requiring large airflow and low static pressure. The flow range is generally between 30 and 80, with static pressure efficiency between 60 and 68, usually shown on the right side of the static pressure curve. Due to the gradually increasing force curve, these fans are prone to overload issues. The advantages include lower cost, lower speed, thinner shafts, smaller bearings, and a wider working range. However, the performance curve may parallel the system’s duct resistance curve, and the static pressure drop in the system may cause motor overload. Additionally, due to the lower strength of the blades, these fans cannot operate at high speeds.
Backward-Curved Blade Centrifugal Cabinet Fans: Compared to the forward-curved fan, the speed vector of a backward-curved fan is about twice as high. The effective airflow range is generally between 40 and 85, with a static pressure efficiency around 80. In general, centrifugal cabinet fans with larger sizes offer higher efficiency under specific operating conditions. Backward-curved blade centrifugal cabinet fans significantly improve efficiency and avoid the overload output curve issue. The power curve is generally larger in the middle of the commonly used range, preventing overload. Moreover, the propeller structure of the backward-curved fan has higher strength and is suitable for higher static pressure systems. Although the fan operates at a faster speed, requiring a thicker shaft and larger bearings, with higher balance requirements, the static pressure efficiency is improved to around 86, and the noise is reduced. Backward-curved fans are particularly favored in high-efficiency, low-noise environments, such as air conditioning terminal manufacturers.
Radial Blade Centrifugal Cabinet Fans: These fans are between forward and backward-curved fans, offering better strength and wear resistance. The blade exit angle is 90°. They are typically used in applications requiring wear and corrosion resistance but are not suitable for other uses.