The DW series centrifugal air-conditioning fan is a low-noise, compact fan built with reference to equivalent international products. Rated flow: 1,000–20,000 m³/h. Total pressure: 200–850 Pa. It uses direct-drive external-rotor motors and offers high efficiency, low noise, high flow, small size and compact construction. It is ideal for VAV air conditioners, ducted air-handling units, VAV systems and other HVAC and air-purification equipment. 

Product Forms 

1. Rotation direction 

DW series fans come in left-hand (LG) and right-hand (RG) versions. Viewed from the motor's terminal end, a clockwise-turning impeller is a right-hand fan; a counter-clockwise one is a left-hand fan. 

2. Outlet direction 

As shown in Figure 1, DW series fans can be made with four outlet directions: 0°, 90°, 180° and 270°. 

Product Structure 

A DW series fan consists of five main parts: casing, impeller, support bracket (frame), motor and outlet flange. 

1. Casing 

The casing is made of hot-dip galvanized steel. The side plates have an aerodynamic profile, the air inlet is integrally drawn, and the volute plate is spot-welded to the side plates as one unit. A series of rivet-nut holes is pre-set in the side plates so the outlet can be installed in the direction the customer requires. 

2. Impeller 

The forward-curved multi-blade impeller is made of hot-dip galvanized steel, with blades shaped to a specific aerodynamic profile for high efficiency and low noise. The blades are secured to the center plate and end ring with riveted claws, giving the impeller ample rigidity during continuous operation at maximum power. Every impeller is tested for both static and dynamic balance, with an internal control target of G2.5 (ANSI/AMCA-204). 

3. Support bracket (frame) 

The bracket is made of galvanized sheet, with a unique reinforcement process that ensures sufficient strength. Its mounting angle can be adjusted to different customer requirements. 

Frames for DW315 and larger fans are welded from angle steel and flat bar, with mounting holes punched on all four sides to suit installation in different directions. 

4. Electric motor 

 DW series fans use external-rotor, low-noise three-phase asynchronous motors, which are characterized by a fixed shaft and a rotating housing. The motor is mounted on the impeller's center plate and drives it directly through the rotation of its housing. On request, DW series fans can be fitted with a special motor that allows stepless speed control via a three-phase voltage regulator, a thyristor regulator or a frequency converter, to meet varying system requirements. 

5. Flange 

The flange is made of hot-dip galvanized steel, and its connection to the casing uses the TOX welding-free process - giving a clean appearance with ample rigidity and strength. 

For flange opening dimensions and types, see Figure 2.