Features

(1) Wide range of specifications and applications: Two types of fans are available to suit different operating pressures, airflow rates, and noise requirements:

a. Axial-flow roof fan: Model DWT-I. Suitable for low- to medium-pressure, high-volume applications. It can also be designed as a reversible fan with bidirectional rotation to meet user requirements, providing equivalent performance in forward and reverse operation (this product has been granted a national patent);

b. Centrifugal roof fan: Model DWT-II. Suitable for applications requiring a relatively low airflow rate and higher pressure.

(2) High efficiency and low noise: The fan is designed and developed using advanced CAD software and multi-objective optimization. This design has received a national utility model patent certificate and a National Excellent Patent Award. Different fan configurations use the same diameter with varying speeds, blade angles, and blade profiles to meet different operating requirements and achieve a good match between the fan and the system, helping to save energy and reduce noise;

(3) Lightweight, high strength, and corrosion resistant: Depending on the corrosiveness of the working medium, the fan impeller can be made from different materials, including ABS (engineering plastic), steel-reinforced FRP (fiberglass), and aluminum alloy sheet. For centrifugal fans requiring higher pressure and operating at higher speeds, the impeller surface receives special galvanizing and corrosion-resistant coating treatments. This reduces the overall weight of the fan while providing good corrosion resistance;

(4) Stable operation and long service life: The fan has a low moment of inertia, high dynamic balancing accuracy, and stable operation. Its performance indicators exceed the requirements of the factory's internal control standards and the fan industry standards, ensuring reliable long-term operation;

(5) Wide range of applications: The fan can be manufactured in explosion-proof or flame-retardant versions, or configured for aging-resistant extraction and for conveying or exhausting flammable, explosive, or corrosive gases, according to application requirements;

(6) Attractive appearance: The fan cowl is made of fiberglass and finished with an imported gelcoat resin film, with smooth, attractive contours and excellent practicality. At the user's request, a steel cowl can also be galvanized and then powder-coated (PVC);

(7) Operating conditions: The medium temperature must not exceed 60℃. The gas must not contain excessive viscous substances, and its dust content must be below 100mg/m³. For applications involving higher medium temperatures, a fire-rated high-temperature smoke exhaust fan (which has been granted a national patent) can be manufactured as a roof fan for user applications;

Model Designation

(1) Axial-flow roof fans are available in 17 sizes, with diameters from φ300 to φ1800. Centrifugal roof fans are available in nine sizes, with diameters from φ300 to φ1000. Other fan sizes can also be supplied upon request;

(2) The construction of fans in each size can be found in the general assembly drawing. Components include the impeller, fan cylinder, cowl, drive components, louver damper, bird screen, and safety screen;

(3) Fan drive: Model DWT-I fans use direct motor drive. If belt drive is required for a particular application, the company can also manufacture fans accordingly. Roof fans are widely used in large quantities and are available in many configurations to suit different applications. The company can develop and improve fan designs and external structures to meet users' specific technical requirements;

(4) For roof fans with a supply or exhaust pressure above 600Pa, use a centrifugal or centrifugal-axial fan; for pressures of 400–600Pa, use a mixed-flow fan; for pressures below 400Pa, use an axial-flow fan.

Performance and Selection

(1) DWT-I axial-flow roof ventilator performance parameters

Variable Angle

Variable Angle (continued)

DWT-I Performance Curves