In May 2026, a gathering of the world's leading scholars – the Global University Summit Cooperation Summit (GCSU 2026) – concluded successfully in Christchurch, New Zealand. Co-hosted by Massey University and the University of Colorado, this international conference attracted representatives from universities across the United States, New Zealand, Singapore, Indonesia, China, and other countries. One of the core topics of the conference was the "Net Zero Future" and innovations in sustainable air purification technology. Professor Liu Junjie from the Tianjin Key Laboratory of Indoor Air Environment Quality Control at Tianjin University shared the latest research findings and reached consensus with multiple global universities on future collaborative research into sustainable air purification technology.

This international dynamic sends a clear signal: in the post-pandemic era, indoor air quality has evolved from a pure health issue to a global sustainable development challenge. Meanwhile, market data confirms this trend. According to All View Cloud (AVC) data, in the first quarter of 2026, China's air purifier market achieved total retail sales of 1.55 billion yuan, a year-on-year increase of 14.3%, with retail volume of 985,000 units, a year-on-year increase of 21.6%. More notably, Co-research Industry Institute's statistics and forecasts show that global air purifier market sales reached approximately 51.9 billion yuan in 2025, and are expected to reach 13.6 billion yuan in 2026. This indicates steady and sustained expansion of the global air purifier market.

Against this industrial backdrop, the core technology selection of air purifiers – especially the design of the fan system – is undergoing a profound transformation. This article will explore in depth the application advantages of cross flow fans in air conditioners and air purifiers, and analyze why more and more manufacturers are choosing the small cross flow fans from China Chungfo Fan as their core airflow solution.

Chapter 1: Evolution of Air Purifier Market Demand and 2026 Trends

1.1 From "Optional" to "Essential": The Changing Market Positioning of Air Purifiers

Looking back over the past five years, the air purifier market has experienced a complete cycle from explosive growth in the early pandemic period to the current phase of normalized development. Entering 2026, the logic of market growth has fundamentally changed. According to AVC data, a significant scissors difference has emerged between volume and value growth in China's air purifier market in Q1 2026 – retail volume grew 21.6% year-on-year, while retail sales grew only 14.3%. This data clearly indicates that the market average price is showing a structural downward trend, with cost-effective mid-to-low-end products becoming the main driver of sales growth.

What does this mean? It means air purifiers are transitioning from "premium consumer goods" to "household necessities." More ordinary families are incorporating air purifiers into their daily shopping lists, and the industry is activating household replacement and upgrade demand at more accessible price points.

1.2 Segment Explosion: The Rise of Pet Purifiers

One of the most noteworthy industry trends in 2026 is the explosive growth of the pet purifier segment. AVC monitoring data shows that online pet purifier sales in Q1 2026 reached 130 million yuan, a substantial year-on-year increase of 47.6%, with market share rising from 9.4% a year ago to 12.4%.

Why have pet purifiers suddenly become so popular? Behind this is the continued growth of the pet economy. For pet-owning families, three core pain points exist: floating hair dispersion, lingering odors, and pet allergens. Traditional purifier filter designs are not optimized for these scenarios – pet hair easily clogs filters, odor molecules require stronger adsorption capacity, and allergens need efficient interception and inactivation.

These segment scenarios impose new technical requirements on air purifier design: the airflow system must be able to handle high-load hair intake without clogging, while maintaining sufficient airflow coverage throughout the room. This is precisely where cross flow fans excel.

1.3 Rise of Multi-function Devices: Purifier-Humidifier Combos

Another trend worth noting is the rapid growth of purifier-humidifier combo units. According to AVC online monitoring data, online sales of purifier-humidifier combos in Q1 2026 reached 130 million yuan, a substantial year-on-year increase of 170.7%; retail volume reached 86,000 units, a surge of 210.8% year-on-year; market share jumped from 4.8% in Q1 2025 to 11.6%.

This trend reflects growing consumer demand for "one-stop air solutions." Users don't want to place a purifier, a humidifier, and a fan in their living room – they want one device that solves multiple problems. This imposes higher demands on the fan system design: not only must it provide sufficient purification airflow, but it must also ensure uniform air distribution in humidification mode, avoiding the phenomenon of "dry on one side, wet on the other."

1.4 Core Challenges Facing the Market in 2026

Synthesizing the above trends, we can summarize three core challenges facing air purifier manufacturers in 2026:

First, how to improve performance while controlling costs? The mid-to-low-end market is becoming the main driver of growth, meaning manufacturers must achieve higher CADR values and lower noise within limited BOM costs.

Second, how to meet the special needs of segment scenarios? Pet purification requires anti-clogging design, in-vehicle purification requires low-voltage operation capability, and baby/maternal purification requires extreme silence.

Third, how to respond to global technical standards? At the 2026 GCSU summit, experts from various countries reached consensus on sustainable air purification technology, meaning future purifiers must not only purify effectively but also be energy-efficient, environmentally friendly, and made from recyclable materials.

Facing these challenges, fan system selection has become one of the key factors determining product success. Cross flow fans, with their unique structural advantages, are becoming the preferred choice for more and more manufacturers.

Chapter 2: Technical Principles of Cross Flow Fans and Application Advantages in Air Purifiers

2.1 What Is a Cross Flow Fan?

Before diving into the discussion, it's necessary to clarify a basic concept: what is a cross flow fan?

A cross flow fan (also known as a tangential fan or transverse fan) features a long cylindrical impeller with blades arranged axially. Unlike traditional axial fans (where airflow enters and exits parallel to the axis) and centrifugal fans (where airflow enters axially and exits radially), the cross flow fan's airflow path is: air enters radially from one side of the impeller, passes through the impeller interior, and exits from the opposite radial side.

This unique airflow path brings several key characteristics:

Extremely uniform airflow distribution: Because airflow is uniformly distributed along the entire length of the impeller, cross flow fans can create a "curtain-like" airflow across a long outlet.

Inlet and outlet are nearly coplanar: This allows for very compact duct designs, ideal for slim-profile devices.

Long-distance air delivery: Cross flow fans generate airflow with a certain Coanda effect, capable of traveling long distances along walls or ceilings.

2.2 Cross Flow Fan vs. Other Fan Types

To better understand the advantages of cross flow fans, let's compare them with the two other mainstream fan types:

Axial Fans: This is the most common fan type, such as household electric fans and computer case fans. Advantages include high airflow, low cost, and simple structure. Disadvantages include unidirectional airflow direction, thickness limitations, and significant airflow attenuation under high static pressure. In air purifiers, using an axial fan limits the purifier's thickness based on the fan diameter, making ultra-slim designs difficult.

Centrifugal Fans: Also known as turbo fans or blowers. Advantages include high static pressure, concentrated airflow, and compact size. Disadvantages include relatively high noise (especially high-frequency noise), uneven airflow distribution, and complex duct design. In air purifiers, centrifugal fans are often used behind HEPA filters that require high static pressure, but their "point source" air discharge characteristic requires additional flow-guiding structures to distribute airflow evenly.

Cross Flow Fans: Combine some advantages of both types. They provide long outlet lengths with uniform airflow distribution while achieving efficient air delivery in compact spaces. Disadvantages are that the maximum airflow at equivalent size is typically lower than axial fans, and manufacturing costs are relatively higher.

In air purifier applications, the advantages of cross flow fans precisely address core product design pain points: the outlet needs to be long enough to cover a larger area (especially for tower purifiers), the duct needs to be thin enough to accommodate more filter media, and noise needs to be low enough to meet home environment requirements.

2.3 Typical Applications of Cross Flow Fans in Air Purifiers

Currently, cross flow fans are mainly used in the following types of air purification equipment:

Tower air purifiers: This is the most common application scenario. The flat, long structure of cross flow fans perfectly matches the vertical duct design of tower purifiers, with air intake at the bottom and exhaust at the top, allowing airflow to pass through the entire unit.

Indoor air conditioner units: The combination of air conditioning and purification functions has been a trend in recent years. Cross flow fans are already very mature in indoor air conditioner units, with their long, strip-shaped outlets capable of covering the entire room width.

Wall-mounted fresh air systems: Wall-mounted fresh air systems need to achieve bidirectional airflow within limited thickness, making cross flow fans an ideal choice.

In-vehicle air purifiers: Car interiors have limited space and impose extremely high requirements on fan size and noise, and miniaturized versions of cross flow fans perform excellently in such applications.

Chapter 3: China Chungfo Fan and Technical Solutions for Small Cross Flow Fans

3.1 About China Chungfo Fan

China Chungfo Fan (full name: Guangdong Chungfo Electronic Technology Co., Ltd.) is one of China's leading fan manufacturers. Since its establishment in 2000, the company has focused on the R&D and production of high-quality fan products including AC fans, DC fans, blowers, and cross flow fans. The company has a 12,000-square-meter modern factory with an annual output of over 8 million units, an R&D team of more than 20 people, and independent mold development and thermal simulation capabilities. Products are exported to markets in Europe, America, Southeast Asia, and the Middle East, providing professional cooling and airflow solutions for home appliances, industrial equipment, ventilation systems, and other fields.

Chungfo is not just a fan manufacturer but also a technical service provider offering customized airflow solutions. Addressing the specific needs of air purifiers, Chungfo has deeply optimized its cross flow fan product line, launching multiple small cross flow fan series specifically designed for air purification scenarios.

3.2 Core Features of Small Cross Flow Fans Used in Air Purifiers

The series of small cross flow fans used in air purifiers from Chungfo has been developed specifically for the special requirements of home, in-vehicle, and portable air purifiers. The core technical features of this product series are as follows:

Compact Structural Design

Traditional cross flow fans typically have diameters of 60mm or more, while Chungfo's miniaturized series compresses the diameter to 30mm-40mm, with lengths covering a range from 80mm to 300mm. This allows the fans to be easily embedded into various slim purifier bodies without occupying valuable space needed for filter media.

Uniform Airflow Distribution

Through advanced Computational Fluid Dynamics (CFD) optimization of blade angles and impeller structure, Chungfo cross flow fans achieve airflow uniformity within ±5% across the entire outlet length. This means from the left side to the right side of the purifier outlet, the air velocity experienced by the user shows almost no difference – this is crucial for enhancing user experience.

Low-Noise Operation

Noise is an area where cross flow fans excel. Chungfo uses dynamically balanced aluminum alloy impellers combined with precision ball bearings to control operating noise within the 30-50 decibel range, comparable to a library environment or the volume of a quiet conversation.

Diverse Voltage Platform Options

To accommodate power supply designs and application scenarios in different global markets, Chungfo offers a rich range of voltage options:

For in-vehicle purifiers or low-power portable devices, Chungfo provides the powerful 12v air purifier high speed fan series. These fans can achieve high speeds of 4000-5000 RPM at 12V DC, with maximum airflow reaching 18-43 CFM, while supporting a starting voltage as low as 7V and an operating voltage range covering 7V-13V.

For performance-oriented home purifiers and industrial applications, the 24v fan 80mm series is an ideal choice. These fans use three-phase brushless DC motors (BLDC) with a rated voltage of 24V, an impeller diameter of 80mm, power of approximately 31W, maximum static pressure of up to 70Pa, and maximum airflow of up to 800m³/h. The advantage of the 24V voltage platform is that, at the same power level, current is lower and heat generation is reduced, making it suitable for long-duration continuous operation.

For large vertical models, the 89mm cross flow fan, with its extended impeller length (customizable to over 600mm), can cover a wider air outlet area, achieving "full-space air supply." This type of large-size cross flow fan is typically used in high-performance purifiers with CADR values exceeding 800m³/h.

3.3 In-Depth Interpretation of Technical Parameters

Taking a typical small cross flow fan from Chungfo used in air purifiers as an example, let's interpret the meaning behind its technical parameters:

Impeller Size: 150mm (length) × 30mm (diameter)

Rated Voltage: DC 12V

Current Range: 0.15 ~ 0.53A

Speed Range: 2,500 ~ 4,500 RPM

Airflow Range: 22.50 ~ 43.47 CFM

Noise Range: 35 ~ 47 dB

Static Pressure Range: 0.60 ~ 2.80 mmH₂O

Lifespan: 50,000 hours (at 25°C)

Bearing Type: Sleeve bearing or dual ball bearing

Frame Material: Cold-rolled steel

Impeller Material: Aluminum alloy

Several key indicators deserve special attention:

Balance between Airflow and Noise: At maximum airflow of 43.47 CFM, noise is only 47 dB. This means even if users run the fan at high speed at night, they won't be disturbed by noise.

Long Life Design: An MTTF lifespan of 50,000 hours means that if the purifier runs 8 hours a day, 365 days a year, it can be used for over 17 years. This far exceeds the designed lifespan of ordinary home appliances.

Aluminum Alloy Impeller: Compared to plastic impellers, aluminum alloy impellers have higher rigidity and better dynamic balance characteristics, resulting in less deformation at high speeds, lower noise, and longer lifespan.

Wide Voltage Adaptability: An operating voltage range of 7V-13V means even in environments with car battery voltage fluctuations (such as voltage drop during engine starting), the fan can operate stably.

Chapter 4: Why Choose Small Cross Flow Fans from China Chungfo Fan – In-Depth Technical Analysis

When manufacturers develop high-performance air purifiers, fan selection is often one of the most critical technical decisions. An incorrect fan choice can lead to a series of problems such as failing to meet CADR targets, noise complaints, and high after-sales failure rates. So why are more and more brands choosing small cross flow fans from China Chungfo Fan? The following analysis examines six dimensions in depth.

4.1 Dimension One: Silent Performance and User Experience

For household air purifiers, noise is one of the most sensitive user experience indicators. No matter how high a purifier's CADR value, if its operating noise resembles that of a vacuum cleaner, users will choose to turn it off at night – and a purifier that is turned off has zero purification effect.

Chungfo has three core advantages in silent design:

First, precision dynamic balance calibration. Every Chungfo cross flow fan undergoes precision dynamic balance calibration before leaving the factory (according to JB/T 9101-1999 standard, G6.3 grade). An unbalanced impeller generates periodic vibration at high speeds, which translates into a low-frequency humming sound – the most intolerable type of noise for users. By controlling the amount of imbalance to the microgram level, Chungfo fans exhibit almost no perceptible vibration even when running at high speeds.

Second, optimized blade design. The noise from cross flow fans mainly originates from vortices generated as blades cut through air. Through CFD simulation, Chungfo optimizes blade angles, thickness, and edge shapes, shifting the frequency distribution of vortex noise from harsh high frequencies (above 2000Hz) to the less sensitive mid-low frequencies (500-1000Hz), making the same sound pressure level sound "softer."

Third, high-quality bearing system. Chungfo offers two options – sleeve bearings and dual ball bearings. Dual ball bearings can achieve a lifespan of over 50,000 hours and generate extremely low friction noise during operation.

In practical applications, air purifiers using Chungfo cross flow fans can achieve sleep mode noise as low as below 35 dB – quieter than a library late at night. For families with infants or elderly members, this is a crucial selling point.

4.2 Dimension Two: Compact Structure and Space Utilization

The internal space of an air purifier is extremely valuable. Filter media needs space, air ducts need space, control circuits need space – and the space left for the fan is often very limited.

The structural advantages of cross flow fans are fully demonstrated here. Unlike centrifugal fans that require complex volutes, cross flow fans have relatively simple duct designs, with the inlet and outlet nearly in the same plane. This means:

Purifiers can be made thinner. Tower purifiers using cross flow fans can have thickness controlled within 150mm, while similar products using centrifugal fans often exceed 200mm in thickness.

Filter media can be larger. With the same overall product volume, cross flow fans occupy less internal space, leaving more room for filter media. Larger filter media means higher CCM (Cumulative Clean Mass) and longer filter replacement cycles – one of the core competitive advantages of high-end purifiers.

Chungfo's small cross flow fan series pushes this space utilization to the extreme. For example, its 30mm diameter micro cross flow fan can be easily embedded into an ultra-slim purifier only 40mm thick, achieving a "wall-hugging" design effect.

4.3 Dimension Three: Airflow Uniformity and Coverage Range

For an excellent purifier, the outlet airflow should be "curtain-like," uniformly covering the entire room. If the airflow is concentrated in a local area, "purification dead zones" will appear in the room – pollutants in distant areas cannot be effectively drawn into the purifier.

Cross flow fans are the natural answer to this problem. Because their airflow is uniformly distributed along the entire impeller length, the outlet can be made as wide as the purifier body itself, forming a complete airflow "curtain." This curtain-like airflow exhibits the Coanda effect, capable of traveling along walls or ceilings to deliver clean air to every corner of the room.

Taking the 89mm cross flow fan as an example, its 89mm impeller diameter combined with customizable length (up to over 600mm) can cover the complete vertical area from floor to ceiling, achieving true "full-space purification."

In contrast, purifiers using centrifugal fans need to add guide vanes at the outlet to "flatten" the airflow, which not only increases airflow resistance and noise but also makes it difficult to achieve truly uniform distribution.

4.4 Dimension Four: Flexibility and Reliability of Voltage Platforms

Power supply standards vary across global markets: China and Europe use 220V AC, the United States uses 110V AC, while automotive and portable devices use 12V or 24V DC. An excellent purifier fan solution must be able to flexibly adapt to these different power environments.

Chungfo's layout in terms of voltage platforms is very comprehensive:

12v air purifier high speed fan series: This is the flagship product for in-vehicle, portable, and low-power scenarios. Rated at 12V, it can operate within a wide voltage range of 7V-13V, with maximum speed reaching 5000 RPM. These fans typically use brushless DC motors and feature multiple safety functions including polarity protection, locked rotor protection, and overcurrent protection. For in-vehicle air purifiers, another advantage of the 12V platform is the ability to draw power directly from the cigarette lighter socket without needing additional voltage conversion circuitry.

24v fan 80mm series: This is the standard configuration for performance-oriented home purifiers and commercial equipment. The 24V voltage platform has lower current (at equivalent power), so motors and wiring generate less heat, making it suitable for devices that need to run 24/7. Chungfo's 24V cross flow fans use three-phase brushless DC motors (BLDC), support PWM or 0-10V signal speed control, and can seamlessly interface with the purifier's intelligent control system.

89mm cross flow fan series: For large vertical purifiers with CADR values exceeding 800m³/h, the 89mm diameter cross flow fan is a more suitable choice. Larger impeller diameter means stronger air delivery capability, generating significantly higher airflow and static pressure at the same speed compared to smaller diameter fans.

This diversified voltage platform strategy allows manufacturers to use fan solutions from the same brand across different product lines, simplifying supply chain management and reducing procurement and inventory costs.

4.5 Dimension Five: Long Life and Reliability Verification

Air purifiers are typical "long-life home appliances," with users expecting a device to last 5-10 years. If the fan exhibits increased noise or stops rotating after just two years, it not only affects user experience but also damages brand reputation.

Chungfo has implemented multiple reliability assurance measures:

Lifespan Design: Chungfo cross flow fans have an MTTF (Mean Time To Failure) of up to 50,000 hours at an ambient temperature of 25°C. What does this mean? Assuming the purifier runs 12 hours a day (daytime + nighttime), 50,000 hours equates to 11.4 years of continuous use. Even at a higher ambient temperature of 30°C, the lifespan still exceeds 30,000 hours.

Material Selection: The impeller uses aluminum alloy instead of plastic. Aluminum alloy has a smaller coefficient of thermal expansion, providing better dimensional stability with temperature changes. Its rigidity is also much higher than plastic, resulting in less blade deformation at high speeds and better maintenance of dynamic balance.

Motor Protection: Chungfo fans are equipped with auto-restart functionality (automatically attempting to restart after locked rotor) and polarity protection (preventing circuit damage from reverse power connection). These functions are standard in industrial-grade fans but not all manufacturers provide them in consumer-grade products.

Testing and Verification: Every Chungfo product undergoes rigorous reliability testing before mass production, including high-temperature aging tests, drop tests, salt spray tests (corrosion resistance), and locked rotor tests.

A strong testament to this is that Chungfo has provided bulk supply to internationally renowned home appliance brands such as Little Swan, and its products have passed multiple electrical and performance tests and obtained UL certification (Certificate Number E311396). Gaining recognition from major brands and passing international safety certifications is itself a powerful endorsement of product reliability.

4.6 Dimension Six: Customization Services and Technical Support

Standard products are certainly important, but in the actual development of air purifiers, "standard" often means "compromise." Every purifier has different duct designs, installation spaces, and heat dissipation requirements, and a truly excellent supplier should be able to provide customized solutions.

Chungfo's customization capabilities are reflected in the following aspects:

Size Customization: From length to diameter, from mounting hole spacing to outlet shape, Chungfo can perform comprehensive customization based on the customer's product structure.

Electrical Parameter Customization: Based on customer targets for airflow, static pressure, and noise, Chungfo can adjust motor winding designs, impeller blade angles, and even develop entirely new molds.

Thermal Simulation Services: Before mold creation, Chungfo's technical team can use CFD software to simulate and analyze airflow distribution of the fan within the complete product, predicting potential issues and optimizing them in advance.

Rapid Prototyping: Benefiting from its in-house mold workshop and R&D team of over 20 people, Chungfo can complete sample production and testing iterations in a relatively short time.

For air purifier manufacturers, this deep customization technical service capability means shorter development cycles, lower development risks, and better final product performance.

Chapter 5: Implications of the 2026 GCSU Summit for Air Purification Technology

Now, let's return to the GCSU summit in May 2026 mentioned at the beginning of this article. What specific implications does this international conference held in Christchurch, New Zealand, have for the air purification industry?

5.1 From "Purification" to "Sustainable Purification"

One of the core topics of GCSU 2026 was the "Net Zero Future." This means that future air purification technology cannot focus only on purification efficiency but must also consider broader sustainability indicators such as energy consumption, materials, and carbon emissions.

For fan systems, this means:

Energy Efficiency Ratio (EER) will become a key indicator. At the same airflow level, fans with higher energy efficiency will gain market favor. Chungfo's DC brushless cross flow fans have significantly higher energy efficiency compared to traditional AC induction motor fans.

Material Recyclability. The aluminum alloy impellers and steel frames of cross flow fans can be 100% recycled when the equipment is discarded, while plastic impellers are much more difficult to recycle.

Long-life design is itself a form of sustainability. A fan that can last 10 years reduces production and disposal by two to three cycles over its entire lifecycle compared to a fan that lasts only three years.

5.2 Interdisciplinary Collaboration Will Spur New Technologies

The GCSU summit emphasized the importance of interdisciplinary research, from the origins of fluid mechanics to aircraft cabin environments and the health impacts of environmental pollution. This interdisciplinary thinking is equally applicable to fan design.

For example, the noise problem of cross flow fans has traditionally been viewed as a purely mechanical vibration issue. But if we introduce a biomedical perspective – that the human auditory system has different sensitivity to different noise frequencies – then the solution is no longer simply to "reduce decibels," but rather to "shift the noise frequency distribution to ranges where the human ear is less sensitive." This is precisely the approach Chungfo adopts in fan design.

Another example: the issue of airflow uniformity has traditionally been solved through experimental trial and error. But if we introduce fluid dynamics simulation and artificial intelligence optimization algorithms, thousands of blade designs can be rapidly tested in a virtual environment to find the optimal solution. This is precisely the technical foundation of Chungfo's CFD simulation.

5.3 Implications of Antarctic Extreme Environment Research

During the GCSU summit, participants reached consensus on exploring the extreme environment of Antarctica. The characteristics of the Antarctic environment are extremely low temperatures (below -40°C), extreme dryness, and long periods of unattended operation.

This imposes extreme requirements on fan reliability: Can it start normally at -40°C? Will the bearing lubricating oil solidify? Can the electronic components withstand the impact of thermal cycling?

Although home air purifiers will not face extreme environments like Antarctica, the temperature by a window inside a room in winter can still drop below 0°C. Chungfo cross flow fans have a wide operating temperature range (-25°C to +60°C), ensuring reliable operation under extreme climatic conditions. When this "military-grade" reliability design trickles down to home products, the result is a "worry-free" user experience.

Chapter 6: Selection Guide – How to Choose the Right Small Cross Flow Fan for Your Air Purifier

6.1 Determine the Voltage Platform

The first step in selection is determining the voltage platform. This depends on the purifier's power supply solution and intended application scenario:

If the product is an in-vehicle air purifier: Choose the 12v air purifier high speed fan series. 12V is the standard voltage for car batteries, allowing direct power draw without conversion. Also verify whether the fan supports wide voltage input (e.g., 7V-13V) to handle voltage fluctuations from the car battery.

If the product is a home purifier powered by 220V AC: The 24v fan 80mm series can be selected, paired with a built-in AC-DC power module. The advantage of the 24V platform is lower current and reduced heat generation, suitable for long-duration operation.

If the product is a portable rechargeable model: Selection depends on the battery voltage, common options being 5V (USB power), 12V, and 24V. A higher voltage platform is generally recommended because, at the same power level, current is lower, resulting in less loss to the battery and wiring.

6.2 Determine Airflow and Static Pressure

Airflow (CFM or m³/h) and static pressure (mmH₂O or Pa) are the two core performance indicators of a fan, and they typically have an inverse relationship – higher airflow means lower static pressure, and higher static pressure means lower airflow.

When selecting a fan for a purifier, the overall system's duct resistance must be considered comprehensively. HEPA filter resistance is typically 20-50Pa, activated carbon filter resistance is 10-30Pa, and duct resistance is 10-20Pa. Summing these resistances gives the total static pressure the fan needs to overcome. Given that total static pressure, select the fan model that provides the maximum airflow.

Chungfo's technical team can provide complete product duct testing services to help customers precisely match fan and filter performance curves, avoiding inefficient designs where the fan is either undersized or oversized.

6.3 Determine Size and Installation Method

Cross flow fans have two key dimensional parameters: impeller diameter and impeller length. Impeller diameter determines the fan's static pressure capability, while impeller length determines airflow coverage.

Select impeller length based on the purifier's body width: It is generally recommended that impeller length be slightly less than the body width, leaving about 5-10mm of installation clearance. Common lengths include 80mm, 89mm, 150mm, 200mm, 300mm, and others.

Select impeller diameter based on body thickness: The smaller the impeller diameter, the thinner the body into which the fan can be placed. Chungfo offers a variety of diameters from 30mm to 60mm, with the 30mm diameter micro cross flow fan being the ideal choice for ultra-slim purifiers.

6.4 Confirm Noise Requirements

Noise is one of the most sensitive user experience indicators for air purifiers. Set reasonable noise targets based on the purifier's usage scenario:

Sleep Mode: Recommended ≤35 dB, which is library-level quietness.

Auto Mode (Medium Speed): Recommended ≤45 dB, comparable to the volume of a quiet conversation.

High Speed Mode (Maximum Airflow): Recommended ≤55 dB, comparable to the volume of a normal conversation.

Chungfo cross flow fans can achieve stepless speed control via PWM signal, allowing the purifier to be nearly silent at low speeds while unleashing full performance when rapid purification is needed.

6.5 Confirm Safety Standards and Certification Requirements

If the purifier is planned for export to overseas markets, it must meet the safety certification requirements of the target market:

North American market requires UL/cUL certification

European market requires CE certification

Chungfo fan products have obtained UL certification (Certificate Number E311396) and CE certification, which can simplify the certification process for the complete product.

Conclusion: Cross Flow Fans – The Key Engine for Technological Upgrading of Air Purifiers

Looking back at the GCSU summit in May 2026, sustainable air purification technology has become a global consensus. Simultaneously, the explosive growth of segment markets such as pet purifiers and purifier-humidifier combos, along with the rapid increase in sales of mid-to-low-end products, collectively form the complex landscape of the air purifier market in 2026.

In such a market environment, the technical selection of core components has become more important than ever. The fan is no longer a secondary component that can be "chosen arbitrarily and installed," but rather a core component that determines the purifier's thickness, noise, energy efficiency, lifespan, user experience, and even overall product competitiveness.

Cross flow fans, with their flat, elongated structure, uniform airflow, and low-noise characteristics, have become the ideal choice for mid-to-high-end air purifiers and indoor air conditioner units. China Chungfo Fan, as a professional manufacturer in this field, provides a one-stop airflow solution for global purifier manufacturers – from standard products to deep customization – through its series of small cross flow fans used in air purifiers, as well as its diversified product matrix including the 12v air purifier high speed fan, 24v fan 80mm, and 89mm cross flow fan.

Choosing Chungfo means not only choosing a fan supplier, but also choosing a technical partner with over 20 years of technical accumulation, thermal simulation capabilities, and customized development experience. In fierce market competition, such a partnership may be exactly the key to making a product stand out.

If your team is developing the next generation of air purifiers or air conditioner products, it is worth seriously considering the cross flow fan solution and the technical capabilities of China Chungfo Fan. After all, in the arena of air purification, whoever can make the air "blow better" holds the key to competitive advantage.