English
The selection of industrial exhaust fans is a systematic project that requires comprehensive consideration of multiple key factors to ensure their efficient, economical, and safe operation. The following are the core factors to consider when making a choice, which can be summarized into several main aspects:
1、 Application scenarios and core requirements
This is the primary basis for selection.
Exhaust purpose:
Cooling: Eliminate workshop high temperatures and equipment heat dissipation (such as injection molding machines and boiler rooms).
Ventilation: Keep the air fresh, replenish oxygen, and eliminate odors (such as in warehouses and underground garages).
Dehumidification/Drying: Control humidity to prevent products from getting damp or moldy (such as in spray painting workshops and food processing).
Dust removal and smoke exhaust: eliminate welding fumes, cutting dust, oil fumes, chemical gases, etc. (such as welding workshops, kitchens, chemical workshops).
Explosion proof: Used in environments with flammable and explosive gases or dust (such as paint rooms, flour mills, petrochemical workshops).
Installation environment:
Indoor or outdoor? Wall material (concrete, color steel plate, etc.) and thickness.
Installation location: roof, side wall, window, or end of pipe?
2、 Performance parameters (technical core)
Airflow (cubic meters per hour, m ³/h):
Key parameters. Calculate based on spatial volume, required air exchange rate, and pollutant generation.
Formula reference: Required air volume=Space volume (length x width x height) x Ventilation rate (times/hour).
The requirements for air exchange rates vary greatly in different scenarios (such as about 20-30 times/hour in ordinary workshops, more than 50 times in high-temperature workshops, and even higher in chemical workshops).
Wind pressure (Pascal, Pa):
Measure the ability of a fan to overcome system resistance such as ducts, louvers, filters, etc.
If the fan is connected to a long pipeline, has multiple bends, or is equipped with purification equipment, a fan with sufficient static pressure must be selected, otherwise the air volume will be severely reduced.
Power and energy efficiency:
On the premise of meeting the air volume and pressure requirements, choose motors with higher efficiency to reduce long-term operating costs. Pay attention to "energy efficiency ratio".
Noise level (decibels, dB (A)):
For workshops near the office area or with noise requirements, low-noise models should be selected or noise reduction measures should be taken.
3、 Fan type and structure
Type selection:
Axial flow fan: With high air volume and low air pressure, it is suitable for direct installation on walls or windows for large-scale ventilation and air exchange, such as on the side of a workshop.
Centrifugal fan: With high air pressure, it is suitable for situations with long pipeline systems and high resistance, such as dust removal and smoke exhaust systems.
Roof fan: directly installed on the roof for upward ventilation, without occupying wall space.
Others: mixed flow fan (between axial flow and centrifugal flow), spray fan (with cooling function), etc.
Material and Construction:
Shell and impeller material: Choose according to the environment. Galvanized steel sheet or plastic can be used in ordinary environments; Stainless steel, fiberglass, or engineering plastics are required for humid and corrosive environments such as electroplating and chemical engineering; High temperature environments require high-temperature resistant materials.
Motor quality: protection level (IP level, such as IP55 for dust and water resistance), insulation level (F level, H level, etc.), explosion-proof (Ex mark), and variable frequency.
Transmission mode: direct connection (high efficiency, low noise), belt transmission (easy to adjust air volume and speed).
4、 Environmental and safety requirements
Protection level (IP code):
Indicates the ability to protect against solid foreign objects and water. High protection level (such as IP54 or above) is required for outdoor or humid dusty environments.
Explosion proof requirements (ATEX/IECEx/national standards):
In areas with explosive risks (Zone 1, Zone 2, etc.), explosion-proof fans that meet the corresponding explosion-proof standards must be selected, including explosion-proof motors and explosion-proof structures.
Corrosion resistance/high temperature resistance:
Select special materials and coatings based on the chemical composition (acid, alkali, organic solvent) and temperature of the exhaust gas.
Fire prevention requirements:
In certain situations, fans may need to pass fire certification or be equipped with fire dampers.
5、 Installation, operation, and maintenance
Installation conditions:
Confirm the structural strength, opening size, and reserved power supply of the installation location.
Consider whether accessories such as blinds (rainproof, windproof, insect proof), protective nets, shock absorbers, silencers, dampers, etc. are needed.
Control method:
Simple switch control, or does it require variable frequency speed regulation (automatically adjusting wind speed based on temperature, humidity, or pollutant concentration)? Do you need remote control or access to building automation systems?
Maintenance convenience:
Whether the design is easy to clean (such as openable access doors), whether the bearings are easy to refuel or replace, and whether the filter screen is easy to disassemble and clean.
6、 Economic considerations
Initial investment cost: equipment procurement cost.
Long term operating costs: Electricity is the main component, and high-efficiency fans are expensive but energy-efficient.
Maintenance cost: replacement cycle and cost of vulnerable parts (belts, bearings).
Summary of selection steps:
Clear requirements: Determine what to discharge (heat, moisture, dust, air) and where to discharge it.
Calculation parameters: scientific calculation of required air volume and pressure (can consult engineers or suppliers).
Initial selection type: Select axial flow, centrifugal, or rooftop fans based on wind pressure requirements and installation location.
Determine specifications: Based on the calculation results, select matching or slightly surplus models from the product sample.
Verification environment: Confirm whether special requirements such as material, protection, and explosion prevention are met.
Evaluate attachments and controls: Determine necessary attachments and control systems.
Compare suppliers: comprehensive performance, quality, service, price, and energy efficiency, choose reliable brands and suppliers.
