Fan Manufacturer’s Guide to Selecting High-Pressure Centrifugal Exhaust Fans

Fan Manufacturer’s Guide to Selecting High-Pressure Centrifugal Exhaust Fans

A high-pressure centrifugal exhaust fan manufacturer shares guidance on fan selection: Five factors influencing the choice of high-pressure centrifugal exhaust fans: Airflow, static pressure; 2. Operating conditions; 3. Gas composition; 4. Installation location and configuration; 5. Accessories, noise levels and other requirements. The airflow of a high-pressure centrifugal exhaust fan is defined as the product of the air velocity V and the cross-sectional area F of the duct. The model of a high-pressure centrifugal exhaust fan should be selected based on the actual conditions of the factory. Attempt to select a fan model that matches the size of the original opening. Maintain a certain distance between the fan and the cooling pads (installed on both sides of the factory gable wall) to achieve good ventilation. The exhaust side of the high-pressure centrifugal exhaust fan should be as far away from nearby buildings as possible to avoid affecting nearby residents. Fan pressure: refers to the resistance that must be overcome when conveying this air volume, i.e., the increase in pressure. However, domestic manufacturers typically opt for total pressure, whilst overseas manufacturers generally favour static pressure. The external residual pressure of a high-pressure centrifugal exhaust fan equals the total pressure resistance of the fans in each process section of the air duct. The resistance of return air ducts is generally calculated at 7–8 Pa/m, whilst that of 90-degree elbows is calculated at 10 Pa per unit. 1. If heating or steam is required, a roof-mounted exhaust fan should be selected where possible. 2. When heating, cooling or supplying fresh air is required, the heated or cooled air should circulate through the occupied areas as much as possible; therefore, duct fans or sidewall fans are frequently used. 3. For fire smoke extraction, roof fans or riser ducts should be used first, with duct fans being the most common choice. Note: Make full use of natural airflow (the position and shape of the fan should be adjusted appropriately). Selecting fans for specific applications Warehouse ventilation (1) To check whether stored goods are flammable or explosive, such as in paint stores, explosion-proof fans should be selected. (2) Depending on noise requirements, environmentally friendly roof fans or centrifugal fans may be selected. (3) Depending on the ventilation volume required for the warehouse, standard SF axial fans or FA exhaust fans may be selected.