The air quality in industrial production workshops and cleanrooms is critical to both worker health and product quality. Among the indicators for evaluating ventilation effectiveness, the “air-exchange rate” stands out. In simple terms, the air-exchange rate refers to how many times the entire air volume of a space is replaced in one hour. This means, for example, if a room requires an air-exchange rate of 5 times per hour, the indoor air is completely replaced by fresh air every 12 minutes. Adequate ventilation carries away harmful gases and heat, replenishes oxygen, and keeps the indoor environment fresh and safe. Various national standards specify the required air-exchange rates in different settings—for instance, GBZ 1-2010 “Occupational Exposure Limits for Hazardous Agents in the Workplace” (Industrial Enterprise Design Hygiene Standards), GB 50019-2015 “Code for Design of Heating, Ventilation, and Air Conditioning in Industrial Buildings,” and GB 50073-2013 “Code for Design of Cleanrooms.” This article will, in layman’s terms, interpret the industrial ventilation and cleanroom air-exchange requirements defined in these standards and introduce how advanced ventilation equipment can fulfill them.
Modern ventilation equipment has greatly improved both the efficiency and reliability of meeting these standards. For example, LONGWELL, an industry-leading supplier of ventilation fans and motors, provides a wide range of specialized fans: axial fans, centrifugal fans, cross-flow (tangential) fans, duct fans, as well as highly energy-efficient EC fans (electronically commutated DC fans) and smart control systems. Next, we will discuss the air-exchange rate requirements in various application scenarios covered by these standards, and see how advanced brands like LONGWELL can help different facilities easily achieve compliance.
GBZ 1-2010: Hygiene Requirements for Air Exchange in Industrial Settings
GBZ 1-2010 “Occupational Exposure Limits for Hazardous Agents in the Workplace” is a key standard in China for occupational health, outlining basic ventilation requirements in industrial facilities. It emphasizes that, whether it’s a general production workshop or a station handling hazardous materials, there must be sufficient fresh air supply and air-exchange rates to protect workers’ health. Generally, workshops are expected to provide at least around 30 cubic meters of fresh air per hour per person (equivalent to roughly 3–5 air exchanges per hour), preventing CO₂ accumulation and hypoxia. If harmful gases or dust (e.g., chemical vapors, particulate matter, welding fumes) are generated during production, a combination of local exhaust ventilation and general ventilation should be adopted. The standard requires significantly higher air-exchange rates in such areas—usually over 10 times per hour—to dilute and remove toxic or hazardous substances, ensuring airborne pollutants remain below occupational exposure limits. The higher the air-exchange rate, the shorter the time harmful substances remain in the air, and the lower the risk to workers.
Beyond routine operation, GBZ 1-2010 also highlights ventilation measures in emergency or accidental situations. For instance, if chemical leaks occur, the ventilation system should be capable of rapidly increasing the air-exchange rate to swiftly expel harmful gases. This calls for ventilation equipment with the necessary performance reserve (high airflow and high static pressure), along with the ability to start up or ramp up speed quickly. Relying solely on natural ventilation is often unreliable; installing sufficiently powerful mechanical ventilation is necessary for compliance.
Selecting high-performance ventilation equipment is thus vital for meeting these hygiene requirements. LONGWELL’s industrial ventilation solutions demonstrate their professional prowess in such scenarios. For example, LONGWELL’s centrifugal blowers, a common type of industrial blower, deliver large airflow and high pressure, enabling continuous and efficient removal of airborne contaminants. Its integrated smart control system can be connected to gas sensors which detect the rise in hazardous gas concentrations and automatically boost the fan’s speed, instantly increasing the air-exchange rate and safeguarding on-site personnel.
LONGWELL Application Case: Emergency Ventilation in a Chemical Plant
At a chemical plant workshop, a sudden incident led to the release of volatile chemical gases. The air was immediately filled with a pungent odor, posing a risk to workers’ health. Fortunately, the workshop had already installed a well-equipped mechanical ventilation system, featuring multiple LONGWELL industrial centrifugal blowers. Following the incident, the main control detected the deteriorating air quality, and LONGWELL’s smart control system immediately escalated the blowers to their highest speed. The powerful exhaust increased the air-exchange rate from 5 times/hour in normal conditions to about 20 times/hour, taking less than 10 minutes to remove most of the toxic gases and bring the indoor air back to safer levels. Throughout the entire process, LONGWELL’s blowers, powered by robust EC motors, maintained stable airflow even under heavy loads. Consequently, this accident was effectively contained, with no serious injuries on site. A post-incident assessment concluded, “We avoided a bigger disaster thanks to the swift response of LONGWELL’s high-performance blowers.” This case vividly shows how strictly adhering to GBZ 1-2010, alongside choosing first-rate ventilation equipment, can significantly enhance the safety of industrial workplaces.
GB 50019-2015: Key Points in Industrial Building Ventilation Design
GB 50019-2015 “Code for Design of Heating, Ventilation, and Air Conditioning in Industrial Buildings” is China’s authoritative specification for HVAC design in industrial plants, guiding the ventilation systems of both new buildings and renovation projects. It aims to improve working environments, ensure safety, and maintain product quality, with a strong emphasis on energy conservation. In the ventilation section, the code provides reference values for air-exchange rates and fresh air volumes based on different building functions and process requirements. For instance, a general machining workshop with relatively low heat and pollutant emissions may be designed for 3–6 air exchanges per hour to maintain comfortable temperatures and air quality. However, areas with high heat processes or significant dust emissions may need 10 or more air exchanges per hour to promptly remove excess heat and dust. Additionally, specialized rooms such as battery rooms and boiler rooms often require separate calculations to ensure that combustible gases don’t accumulate indoors. The code also specifies that ventilation design should factor in seasonal variations and energy usage, employing optimal airflow rates to avoid unnecessary energy waste.
Notably, GB 50019-2015 mandates the use of “advanced technology to effectively utilize and conserve energy,” meaning industrial ventilation must not only meet minimum air-exchange standards but also adopt energy-efficient equipment and smart controls to avoid excessive ventilation and energy waste. This opens the door for next-generation ventilation products. EC fans—electronically commutated fans—are an advanced technology encouraged by the code. Compared to traditional AC fans, EC fans deliver significantly higher energy efficiency (often saving 30% or more), and allow for infinite speed control. When upgrading ventilation in industrial workshops, replacing old fans with EC fans can reduce electricity usage substantially while still meeting air-exchange requirements. The code also supports incorporating intelligent control systems that automatically adjust ventilation based on real-world needs (e.g., workforce size, production conditions, time of day). Such “on-demand ventilation” can fulfill the standard while avoiding wasteful over-ventilation—a win-win approach.
Beyond industrial plants, similar ventilation principles apply to large commercial and public buildings. For example, the ventilation systems in subway stations and tunnels borrow from the same industrial ventilation concepts: high-capacity axial fans operate regularly to remove CO₂ and heat generated by passenger traffic, keeping station air fresh. In the event of a fire, these fans switch to an emergency mode to boost air-exchange rates drastically, expel smoke, and provide fresh air for passenger evacuation. LONGWELL’s large-capacity axial fans play a vital role in such scenarios—the fan blades feature special reinforcement that allows for long-term stable operation under normal ventilation conditions, yet can deliver massive airflow at critical moments, enduring high-temperature smoke while ensuring subway operations and passenger safety.
LONGWELL Application Case: HVAC Upgrades in a Commercial Building
These ventilation codes do not only apply to new projects but also guide improvements in existing structures. A commercial office building completed 20 years ago suffered from inadequate fresh air supply, resulting in stuffy indoor air and frequent employee complaints of dizziness and fatigue. In response, the building management decided to upgrade the HVAC system to current standards, incorporating LONGWELL’s energy-saving ventilation solutions. First, they replaced the outdated and inefficient fans in each floor’s fresh-air units with a combination of high-efficiency axial fans and cross-flow fans from LONGWELL. Designed to achieve around 6 air exchanges per hour, the new fresh-air units now meet the latest indoor air quality requirements (i.e., sufficient fresh air per person). After installation, the offices remain fresh even during peak occupancy, and CO₂ levels are significantly lower than before.
Furthermore, using LONGWELL’s smart control system, the building can adjust ventilation on demand: when occupancy is low (e.g., nights or weekends), fan speed is automatically reduced to minimize needless air exchange; in high-density areas like conference rooms, CO₂ sensors detect increased occupancy and dynamically raise ventilation. This intelligent control precisely matches ventilation with actual needs, thereby cutting energy waste dramatically. In the year after the retrofit, the building’s ventilation energy consumption fell by about 20%, significantly reducing operational costs. Also, thanks to the fans’ smooth and quiet operation (enabled by LONGWELL’s low-noise design), the office environment is noticeably more comfortable. This commercial building’s HVAC upgrade demonstrates that by applying advanced equipment that complies with GB 50019, older facilities can both meet modern ventilation standards and enhance energy efficiency. LONGWELL’s products played a key role in achieving these objectives, underscoring their reliable professional capabilities.
GB 50073-2013: Cleanroom Air-Exchange Rate Standards
Cleanrooms have strict requirements for air cleanliness. From pharmaceuticals and electronics manufacturing to food processing, these specialized environments must control both particulate and microbial loads in the air. GB 50073-2013 “Code for Design of Cleanrooms” stipulates the necessary air-exchange rates and filtration standards for different cleanroom classes. In short, the higher the cleanliness classification (the cleaner the air), the higher the required air-exchange rate. The code provides illustrative examples:
• Class 100,000 (approx. ISO 8): 18–25 air exchanges per hour, requiring that within 40 minutes after a full purge, the room’s air returns to compliant cleanliness levels. Though relatively lower than other cleanrooms, nearly 20 exchanges per hour is still far above typical industrial workshops. This ensures continual removal of particles from personnel movement and manufacturing processes, keeping particle concentrations at no more than 100,000 per cubic meter.
• Class 10,000 (approx. ISO 7): 25–30 air exchanges per hour, with full air purification recovery within 30 minutes. Notably, the requirements increase with cleanliness, enabling faster particle clearance. Such cleanrooms are common in precision electronics and medical device production.
• Class 1,000 (approx. ISO 6): 40–60 air exchanges per hour, with a 20-minute recovery time. The airflow is almost constantly at high speed to maintain extremely low particle counts (e.g., only a few thousand particles per cubic meter). Higher classifications such as Class 100 or Class 10 can even demand hundreds of exchanges per hour, typically achieved via unidirectional laminar airflow systems.Evidently, cleanrooms mandate much higher air-exchange rates than general environments, since these spaces must maintain extremely low particulate and microbial levels by continuously diluting and removing contaminants with high-volume filtered air. Cleanroom ventilation usually employs multiple filtration stages (pre-filters, mid-level, and HEPA or ULPA filters), so the supply fans must provide sufficient airflow and static pressure to overcome filter resistance. Moreover, the design typically maintains a positive pressure within the cleanroom (generally ≥5Pa pressure difference from adjoining less-clean areas), preventing unfiltered air from seeping inside. To meet these stringent requirements without incurring excessive energy costs, GB 50073 encourages the use of advanced fan and control technologies that increase fan efficiency and optimize airflow.
In light of these demanding cleanroom standards, LONGWELL delivers robust solutions. Its line of centrifugal fans (including backward-curved centrifugal fans) is particularly suited to cleanroom air handling units. These fans can supply high static pressure and stable airflow, driving air through multiple filter stages without significant loss. Compared to conventional products, LONGWELL’s EC centrifugal fans are more efficient, reliable for continuous 24-hour operation, and more energy-saving. Additionally, the accompanying smart monitoring system automatically adjusts fan speed based on sensors measuring particle counts or differential pressure: if a rise in particle concentration is detected, the system speeds up the supply fans to restore cleanliness; when activity decreases, it lowers the fan speed to conserve energy. Thanks to such smart controls, the cleanroom consistently meets the standard for cleanliness at reduced operating cost. Since high-grade cleanroom ventilation is a major energy consumer, any boost in efficiency yields substantial savings. LONGWELL’s fans also feature low noise and vibration, highly beneficial in quiet laboratory settings where equipment noise can disrupt operations.
LONGWELL Application Case: Cleanroom Ventilation in an Electronics Facility
A major electronics manufacturer built a Class 10,000 (ISO 7) cleanroom for assembling precision components. Under GB 50073-2013, this cleanroom requires approximately 25 air exchanges per hour to maintain ISO 7 cleanliness, as well as stable temperature, humidity, and positive pressure. The company adopted a comprehensive cleanroom HVAC solution from LONGWELL, with multiple centrifugal fan modules powered by high-efficiency EC motors installed in the air handling units (AHUs) and main supply ducts. During commissioning, these fans continually delivered filtered air into the cleanroom. Through precise variable-frequency control, they maintained about 25 exchanges/hour during normal production to keep particle and microbial counts in compliance with Class 10,000. Whenever in-room particle counters neared their limit, LONGWELL’s smart control system immediately increased the fans’ speed—for instance, to 30 exchanges/hour—thus boosting air circulation and restoring cleanliness in under 30 minutes. Owing to the fans’ exceptional efficiency, this setup consumes nearly 20% less power than a traditional design, resulting in considerable annual savings.
Additionally, the fans’ stable and quiet operation leaves the cleanroom nearly devoid of mechanical noise or vibration, providing employees a comfortable, distraction-free environment. More importantly, since its deployment, this cleanroom has never experienced a product quality issue due to inadequate ventilation. The client’s lead engineer stated, “LONGWELL’s ventilation system gives us absolute peace of mind about our cleanroom environment—not only does it meet the strict requirements, but it also saves on operating costs.” It is evident that in such demanding environments, choosing a specialized ventilation product like LONGWELL is undoubtedly a smart way to ensure both compliance and operational efficiency.
Conclusion
Whether it’s an industrial workshop or a high-end cleanroom, effective ventilation and air exchange form the bedrock of safety and product quality. Thanks to national standards, we understand how many air changes per hour are needed in different environments—enough to prevent hazardous substances building up in industrial settings, or to sustain ultra-low particle counts in cleanrooms. Though these numbers may appear stringent, they safeguard health and quality. Fortunately, advancements in ventilation technology provide reliable means to meet (and surpass) these standards. With a wide range of products and technical expertise, leading fan manufacturers like LONGWELL offer tailored ventilation solutions for diverse scenarios: high-efficiency EC fans cut energy consumption, axial fans deliver large airflow, centrifugal fansovercome high resistance to ensure stable delivery, and cross-flow fans distribute air quietly and evenly in spacious areas—supported by advanced intelligent control for precise adjustment. Thanks to their comprehensive professional capabilities, LONGWELL’s ventilation products can easily help users meet national air-exchange requirements while further improving energy efficiency, lowering noise, and reducing operating costs—a dual advantage for both economy and society.
Ventilation is crucial for each worker’s respiratory health and every product’s reliability. As the public becomes increasingly conscious of air quality, we now have both the reasons and the resources to make these standards a visible reality. We hope this article has given you a clearer understanding of industrial ventilation and cleanroom air-exchange requirements, while leaving you with a strong impression of LONGWELL’s professional competency and value. In the future—be it in factory workshops, tall buildings, subway tunnels, or cleanroom facilities—LONGWELL will continue to safeguard fresh air with its outstanding ventilation technology, ensuring safe and healthy environments for both production and daily life.
