Views: 242 Author: Site Editor Publish Time: 2026-07-24 Origin: Site
Fans serve as the power core of complete systems for factory ventilation, waste gas treatment, kiln flue gas exhaust and dust collection projects. Numerous problematic cases frequently occur in actual engineering applications: brand-new fans operate with noise exceeding 95 decibels, making normal workshop production impossible; fans with labeled sufficient air volume still fail to cool the plant, resulting in persistent sweltering conditions; motors burn out and impellers suffer corrosive perforation within less than half a year of operation, causing huge losses from production halts and maintenance.
Many purchasers and designers only simply check two parameters: air volume and air pressure, while ignoring critical details such as working medium, unit matching, energy efficiency, noise reduction and supporting installation accessories. Though this seems to cut procurement budgets, the subsequent costs of rectification, maintenance and electricity bills will end up several times higher.The core principle of fan selection can be summed up in one sentence: match the working condition requirements, select suitable models, and balance upfront procurement costs and long-term operation & maintenance expenses. The seven practical key points below cover the selection demands of 90% of industrial ventilation scenarios.
To boost air volume or air pressure, two fans are often connected in parallel or series in many projects. However, it is difficult for the performance curves of the two fans to fully coincide. During operation, one fan is highly likely to be overloaded while the other idles with low load, leading to a sharp drop in overall operating efficiency.
Potential Risks：If one fan breaks down and shuts down, the other will instantly run under excessive load, which will directly burn out its motor.
Standard Solutions：
Prioritize a single large-size fan instead of a combination of multiple fan units.
If parallel or series connection is mandatory, select fans of the same model and identical performance uniformly.
For series fan installation, reserve standard transition pipelines between the two-stage units; direct butt joint of air outlets is prohibited.
Purchasing fans without prior market research is a leading cause of improper fan selection. Three categories of information shall be fully clarified before selection:
Main product lines, technical strengths and applicable industries of mainstream domestic fan manufacturers;
Technologies of new energy-saving and low-noise industrial fans in the industry, as well as their energy consumption gaps compared with conventional models;
Whether the products comply with current environmental standards for industrial waste gas and dust emission.
Environmental compliance is a mandatory threshold. If the fan fails to meet the standards for emission, explosion protection and anti-corrosion performance, the project will not pass final acceptance, and subsequent renovation costs will be extremely high.
Practical Suggestion: Compare at least three suppliers before finalizing the solution, and conduct horizontal comparisons on fan performance parameters, complete machine quotations, warranty periods and after-sales maintenance services.
The composition, temperature, dust content and corrosiveness of conveyed gas determine fan materials and models. Improper use of ordinary fans will easily trigger safety accidents and rapid equipment deterioration:
Flammable and explosive chemical gas: Adopt explosion-proof fans. High temperature and sparks generated during the operation of ordinary fans carry explosion risks.
High-dust environments such as coal mines and cement plants: Special dust exhaust fans equipped with thickened wear-resistant impellers to prevent ordinary impellers from quick abrasion and scrappage.
Acid-base corrosive waste gas: Anti-corrosion fans. 304 stainless steel for mildly corrosive conditions; upgrade to 316L or titanium alloy for heavily corrosive working environments.
High-temperature flue gas from boilers and kilns: Special high-temperature boiler induced draft fans with heat-resistant impellers and casings that can withstand temperatures of several hundred degrees Celsius.
If multiple fan models can satisfy the working conditions in terms of air volume and total pressure, follow the selection principle: efficiency first, size second, adjustability supplementary:
High-efficiency fans deliver remarkable power savings during long-term operation. For a 75 kW fan, a mere 5% difference in efficiency can lead to an annual electricity cost gap of tens of thousands of yuan, aligning with enterprises’ energy conservation and carbon peaking & carbon neutrality targets.
Compact fan units occupy less factory floor space, cut construction costs for ductwork and mounting bases, and simplify later inspection and maintenance.
Give priority to models with wide adjustment ranges to cope with fluctuations in air volume and pressure caused by varying production conditions.
Low price or high-end specifications alone shall not govern fan selection; the optimal solution lies in comprehensive compatibility with your actual working conditions.
Practical industry procurement tip: Standard centrifugal fans equipped with a motor power of ≤75kW do not require additional dedicated start dampers, which can directly reduce equipment procurement costs.
The only exception applies to boiler induced draft fans conveying high-temperature flue gas. During cold startup, air density is high, resulting in a fan operating load far exceeding that under normal high-temperature working conditions. Without a start damper, the motor is prone to overload burnout.
Supporting recommendation: Electric or pneumatic regulating dampers shall be adopted as start dampers, which can be connected to the fan automatic control system for linked startup and shutdown.
Excessive noise in most factory workshops stems from neglect of noise reduction design during the initial fan selection phase. Fan noise not only endangers workers’ occupational health but also fails to meet plant occupational hygiene standards. Three core principles for noise reduction fan selection:
For fans with identical air volume and total pressure, select units with lower impeller peripheral speed and rotational speed to cut aerodynamic noise at the source.
Keep the fan operating at its high-efficiency operating point long-term; deviation from the high-efficiency range will simultaneously amplify noise and vibration.
Equip a complete vibration and noise reduction system: install spring or rubber vibration isolators under the fan base, adopt flexible connections at air duct joints, and fit dedicated silencers on air ducts.
Impeller diameter replacement is common for process upgrades and stock replacement, yet the new impeller cannot be directly assembled and put into service. Variations in impeller dimensions alter the overall dynamic parameters of the fan, bringing risks such as excessive vibration, shaft fracture and motor overload. Three key sets of data must be calculated:
Motor starting load: Enlarged impeller diameter leads to increased moment of inertia, which may exceed the starting capacity of the original motor.
Load bearing capacity matching of bearings, couplings and base supports.
Critical rotating speed of the shaft system, to prevent violent vibration and shortened service life caused by operating speed approaching the critical speed.
Mandatory standard: A full set of dynamic calculation and verification is required if the impeller diameter is adjusted by more than 15%, to confirm the original accessories can withstand the corresponding load.
Clarify the bottom line of working conditions: gas corrosion, temperature, dust content and explosion-proof requirements determine the basic fan type.
Match parameters precisely: air volume, total pressure, operating efficiency and noise control to confirm the suitable model.
Calculate full-lifecycle costs: do not only focus on the purchase price; prioritize long-term electricity expenses and maintenance & replacement costs.
There is no one-size-fits-all model for industrial fan selection. Screening fans for your actual production conditions by referencing the seven core key points can drastically reduce various risks including equipment failure, excessive energy consumption and failure to pass environmental acceptance inspection.
1.What is the difference between explosion-proof fans and ordinary fans?
Explosion-proof fans are mandatory for conveying flammable and explosive gas, featuring fully explosion-proof sealing and spark-free construction. Ordinary fans are strictly prohibited for hazardous areas such as chemical plants and paint workshops.
2.How to solve excessive fan noise?
Prioritize low-speed and high-efficiency fans, equipped with vibration-damping bases, duct silencers and flexible connections. The combined multi-layer noise reduction solution delivers optimal performance.
3.Why are start dampers compulsory for boiler induced draft fans?
The density of flue gas is high under cold conditions, leading to heavy load during no-load startup. Dampers adjust air pressure to protect the motor from overload damage.
