Plasma Air Sterilizer: The Invisible Air Guardian – How Does Its Practical Value Truly Deliver?

I. What Is a Plasma Air Sterilizer? What Key Logic Lies Behind Its Disinfection Principle?

Against the backdrop of growing attention to indoor air quality today, Plasma Air Sterilizers are gradually moving from professional medical settings (such as sterile hospital wards) to everyday scenarios like ordinary family living rooms. However, when faced with this device, most people only know it "purifies air" but have a vague understanding of its underlying operating mechanism, and even confuse it with regular air purifiers. In fact, the core technical support for this type of device is low-temperature plasma technology, and its operating process is far more complex than simple "filtration".

When the device is powered on and activated, the internal high-voltage generator releases high-frequency pulsed current, creating an asymmetric plasma electric field between the electrodes. The intensity of this electric field is sufficient to break down oxygen molecules in the air – it is important to note that oxygen molecules themselves have a stable diatomic structure, but under the influence of a strong electric field, the chemical bonds between molecules are broken, generating a large number of high-energy particles. These particles are not a single component but a "pure high-energy active oxygen group" composed of pure oxygen, single-atom oxygen, hydroxyl radicals (·OH), negative ions, and more. Among them, the redox potential of hydroxyl radicals reaches 2.8V, far exceeding that of common disinfectants like chlorine and ozone, which is the key to its strong disinfection capability.

What is more noteworthy is its "low-temperature operation" characteristic. Many people may worry whether such an intense electric field reaction will generate high temperatures, affecting the surrounding environment or items. In reality, during the plasma reaction process, although the temperature of electrons can reach tens of thousands of degrees Celsius, the temperature of heavy particles (such as atoms and molecules) remains within the normal temperature range. The outer shell temperature of the entire device usually does not exceed 40°C, which will not add extra thermal burden to the indoor environment nor cause thermal damage to furniture, electrical appliances, or other items.

These high-energy active components in the air diffuse and actively undergo precise electrochemical reactions with various harmful substances. For bacteria and viruses, the active particles directly penetrate their cell walls or viral envelopes, destroying internal protein structures and nucleic acids (such as DNA and RNA), causing microorganisms to lose their ability to reproduce or even be inactivated directly. According to tests by internationally recognized third-party testing institutions (such as laboratories with ISO or ILAC certification), compliant plasma air sterilizers can achieve a disinfection rate of over 99.9% for Staphylococcus albus, a stable disinfection rate of around 99% for Escherichia coli and Staphylococcus aureus, and even for more complex viruses like H1N1 influenza virus and novel coronaviruses, the viral load in the environment can decrease by over 90% after the device operates for 30 minutes.

In addition to disinfecting microorganisms, its treatment method for volatile organic pollutants (VOCs) such as formaldehyde, benzene, and TVOC (Total Volatile Organic Compounds) is also completely different from that of traditional devices. Traditional activated carbon adsorption only "temporarily stores" pollutants in the filter, and once the adsorption is saturated, secondary pollution will occur; in contrast, the active particles in plasma undergo step-by-step degradation reactions with these organic compounds – taking formaldehyde as an example, hydroxyl radicals first decompose formaldehyde (CH₂O) into carbon dioxide (CO₂) and water (H₂O), with no harmful intermediate products generated throughout the process, truly eliminating pollution at its source.

It is particularly important to remind that some people may worry about whether excessive ozone will be generated during the operation of plasma devices, causing harm to the human body. In fact, compliant plasma air sterilizers are all equipped with an ozone concentration control system. By precisely adjusting the electric field intensity and discharge frequency, the ozone emission can be strictly controlled below 0.12mg/m³, which is far lower than the internationally accepted indoor air safety threshold (usually set at 0.16mg/m³, in line with the indoor air quality recommendation standards of the World Health Organization and most countries). In daily use, even if the device operates continuously for 24 hours, the indoor ozone concentration will not irritate the human respiratory tract, eyes, or other mucosal tissues, and its safety is fully guaranteed.

II. Compared with Traditional Devices, Is Its Practical Advantage Truly More Prominent?

In the air purification equipment market, traditional devices such as HEPA filter purifiers, ultraviolet sterilizers, and ozone sterilizers have long occupied a place. When purchasing, many consumers often fall into the confusion of "which one to choose". The practical value of Plasma Air Sterilizers is precisely highlighted in the multi-dimensional comparison with these traditional devices, especially showing irreplaceable advantages in core demand areas such as long-term use costs, safety, and purification range.

The non-consumable feature significantly reduces maintenance costs, which is one of the most recognized advantages of plasma air sterilizers among users. For traditional HEPA filter purifiers, filters are core consumables – primary filters need to be replaced every 1-3 months, medium-efficiency filters every 3-6 months, and high-efficiency HEPA filters every 6-12 months. Taking a set of filters suitable for a 100㎡ house as an example, the cost of a single replacement is usually between 30 and 80, and the annual consumable cost alone can reach 60 to 160. The problem with activated carbon purifiers is even more obvious: activated carbon reaches saturation after 1-2 months of adsorption, and if not replaced in time, it will not only fail to purify the air but also release adsorbed pollutants, causing secondary pollution.

In contrast, the core working components of plasma air sterilizers are electrodes and electric field generators, and the design service life of these components can reach 50,000 to 80,000 hours. Calculated based on 8 hours of operation per day, the core components can be used continuously for 17 to 27 years, and no consumables need to be replaced during this period. Daily maintenance only requires wiping the device shell with a soft dry cloth every week and opening the device panel every quarter to clean the dust on the electrodes with a brush, with no additional costs incurred throughout the process. In the long run, compared with traditional filter-type devices, plasma sterilizers have a very obvious advantage in maintenance costs, making them particularly suitable for long-term use scenarios such as families, schools, and enterprises.

The safety and convenience of coexistence with humans are the core competitiveness of plasma devices compared with disinfection equipment such as ultraviolet and ozone devices. The working principle of ultraviolet sterilizers is to use the bactericidal effect of ultraviolet rays, but ultraviolet rays are highly irritating to human skin and eyes – if the human body is directly exposed to ultraviolet radiation, skin redness and peeling may occur within a few minutes, and symptoms such as eye pain and tearing may appear, and in severe cases, it may damage the retina. Therefore, ultraviolet sterilizers must be used in unoccupied environments, and after disinfection, windows need to be opened for ventilation for more than 30 minutes before entering, which greatly limits their application scenarios and cannot meet the needs of spaces that require continuous human activity, such as offices and bedrooms.

Ozone sterilizers pose even greater safety risks. Ozone has a strong pungent odor, and when the ozone concentration in the air exceeds 0.3mg/m³, it will irritate the human respiratory tract, causing symptoms such as coughing and chest tightness; long-term exposure to high-concentration ozone can also damage lung function. Therefore, ozone sterilizers also need to be used in closed, unoccupied environments, and after disinfection, ventilation is required for 1-2 hours to reduce the ozone concentration, which is not only inconvenient to use but also carries the risk of poisoning due to improper operation.

Plasma air sterilizers completely break this limitation. Due to their extremely low ozone emission and the fact that active particles react quickly with pollutants and are converted into harmless substances during the disinfection process, the device can operate continuously for 24 hours in an occupied environment. Whether there are elderly people, children, or pregnant women at home, or employees working continuously in the office, there is no need to worry about safety risks caused by the device's operation. This "coexistence with humans" feature allows it to be truly integrated into daily life and work scenarios, achieving "all-day air protection".

Full-space purification capability is another major advantage of plasma devices over traditional filter-type purifiers. Traditional HEPA filter purifiers adopt a "passive suction" purification method, which can only treat the air flowing through the interior of the device – air is sucked into the device by a fan, filtered through the filter, and then discharged. The purification range of this method is very limited, usually only covering an area 3-5 meters around the device, and it can hardly play a purification role in corners with poor air circulation, such as under sofas, between cabinet gaps, and under beds. In a 100㎡ living room, if only one filter-type purifier is placed, it may take several hours to make the air quality of the entire space up to standard.

Plasma air sterilizers adopt an "active diffusion" purification method. The high-energy active particles released by the device can diffuse freely in the air and penetrate into every corner of the room, including furniture gaps, deep inside carpets, and air conditioning ducts – areas that traditional devices cannot cover. Taking a 150㎡ office as an example, after a plasma device suitable for this area operates for 1 hour, the bacterial disinfection rate in all areas of the room can reach more than 90%, and the formaldehyde degradation rate can reach more than 85%, truly achieving "dead-angle-free purification". This full-space purification capability is particularly important for large-scale and complex spaces such as hospital wards, school classrooms, and shopping malls.

In terms of energy consumption, plasma devices also have an undeniable advantage. Taking a device suitable for a 150m³ room as an example, its rated power is usually around 150W, while the power of ultraviolet sterilizers of the same specification is generally above 450W, so the energy consumption of plasma devices is only 1/3 of that of ultraviolet devices. Calculated based on 10 hours of operation per day and an electricity cost of 0.15 per kWh, the monthly electricity cost of a plasma device is approximately 6.75, and the annual electricity cost is only 81; in contrast, the monthly electricity cost of an ultraviolet sterilizer is about 20.25, and the annual electricity cost is as high as 243 – the annual electricity cost difference between the two can reach 162. In addition, the design service life of plasma devices can reach 15 years, which is 3 times that of ultraviolet sterilizers (usually with a service life of 5 years). From the perspective of long-term use costs, the advantage is even more obvious.

III. Which Scenarios Most Need the Protection of Plasma Air Sterilizers?

From the perspective of practical application effects, Plasma Air Sterilizers are not "all-purpose devices", but in scenarios with strict air quality requirements, dense populations, or special pollution risks, they can demonstrate irreplaceable value. Whether it is the sterile needs in the medical field, the epidemic prevention needs in public places, or the hygiene standards in industrial production, plasma devices can be accurately adapted, serving as "invisible guardians" of air safety.

The medical and health field is the core application scenario of plasma air sterilizers and also the field where their technology is most mature. In key areas of hospitals such as operating rooms, ICUs (Intensive Care Units), neonatal rooms, and burn wards, the concentration of microorganisms in the air is directly related to the treatment effect and rehabilitation safety of patients – during surgery, if there are bacteria in the air, it may cause surgical incision infections; critically ill patients in ICUs have low immunity and are very vulnerable to viruses and fungi; the respiratory tract and immune system of newborns are not yet fully developed, and their tolerance to air pollutants is extremely low.

The advantages of plasma air sterilizers in these scenarios are particularly prominent. Taking the operating room as an example, 15 minutes after the device is activated, the number of bacterial colonies in the indoor air can drop from an initial 500 CFU/m³ (Colony-Forming Units) to below 50 CFU/m³, meeting the international general first-class clean operating room air standard (in the medical building codes of most countries, the limit for the number of bacterial colonies in first-class clean operating rooms is ≤50 CFU/m³). More importantly, it can operate simultaneously while medical staff are performing surgical operations, without interrupting the surgical process like ultraviolet sterilizers, which not only ensures the sterility of the surgical environment but also improves medical efficiency. In places such as laboratories and biochemical rooms, researchers often come into contact with chemical reagents such as formaldehyde, benzene, and xylene. These substances volatilize into the air and can cause chronic harm to the human body. Plasma devices have extremely strong degradation capabilities for these harmful gases – the formaldehyde degradation rate can reach 91% within 24 hours, and the xylene degradation rate is as high as 96%, which can effectively protect the occupational health of researchers.

The demand for plasma air sterilizers in crowded public places is also urgent. Transportation hubs such as stations, airports, and subway stations have a daily passenger flow of tens of thousands of people. The large and diverse population flow leads to a high risk of virus and bacteria transmission in the air. Although traditional ventilation methods can reduce the concentration of pollutants, during peak hours with dense populations, the ventilation efficiency is far from meeting the demand; filter-type purifiers are also difficult to meet the purification needs of large-scale spaces due to their limited purification range.

Plasma air sterilizers can form a "full-air duct purification system" by combining with central air conditioning and fresh air systems – the device is installed inside the air duct, and when air enters the duct, it first undergoes disinfection and purification through the plasma electric field, and then is delivered to various areas through air outlets. This method not only realizes air purification in the entire space but also reduces the energy consumption loss of the fresh air system by 10%-30%. Taking a large international airport as an example, after installing plasma devices in the fresh air system of the waiting hall, the bacterial disinfection rate in the indoor air remained above 92%, and the viral load decreased by 88%. Moreover, the device operates without noise or odor, which does not affect the passenger experience at all.

Enclosed spaces such as school classrooms and office meeting rooms also need the protection of plasma devices. Dozens of students stay in the classroom for a long time, and if the air is not circulated, it is easy to cause the spread of infectious diseases such as influenza and chickenpox; during meetings in the meeting room, the dense population and increased carbon dioxide and droplets from breathing also increase the risk of air pollution. Plasma devices suitable for such spaces are usually equipped with intelligent control functions, which can be connected to a mobile APP via WiFi. Managers can check indoor air quality data (such as PM2.5 concentration, number of bacterial colonies, and TVOC content) in real time and remotely adjust the device operation mode according to needs. For example, schools can activate the device 30 minutes before class to ensure that the air quality meets the standard when students enter the classroom; enterprises can automatically turn on the high-efficiency purification mode after the meeting to quickly reduce the concentration of indoor pollutants.

The food and pharmaceutical industries have special production needs, which also make plasma air sterilizers indispensable equipment. In food processing workshops, microbial pollution is the main factor affecting food quality and safety – baked goods such as bread and cakes are easily contaminated by mold, while meat and dairy products may be contaminated by Escherichia coli and Salmonella. Traditional chemical disinfection methods (such as spraying disinfectants) can kill microorganisms but leave chemical residues on the food surface, posing safety hazards; ultraviolet disinfection cannot cover the corners and interior of the workshop equipment, resulting in unstable disinfection effects.

The broad-spectrum disinfection capability and no chemical residue characteristics of plasma air sterilizers are precisely suitable for the needs of the food industry. The active particles released by the device can penetrate the gaps of food processing equipment, achieving all-round disinfection of the equipment interior and workshop environment. They can cover stubborn microorganisms such as bacterial spores and mold spores, with a disinfection rate of over 99.9%, and leave no residues on the food surface, complying with the food production hygiene standards of the Codex Alimentarius Commission (CAC) and most countries. In the pharmaceutical filling process, the requirements for air cleanliness are even stricter – any tiny microorganisms or particles may affect the quality of pharmaceuticals. Plasma devices can be used in conjunction with aseptic filling lines to upgrade the air cleanliness of the filling area to the level of Class A clean areas in international standards, ensuring that pharmaceuticals are not contaminated during the production process.

In addition, some models also offer vehicle-mounted plasma sterilizers with a rated power of only 12W, which can be directly powered by the car cigarette lighter. This type of device is particularly suitable for food fresh-keeping transport vehicles – when transporting fresh meat, fruits, and vegetables, the active particles released by the device can inhibit the reproduction of microorganisms, slow down the food spoilage rate, and extend the fresh-keeping period. For example, using a vehicle-mounted plasma device in a strawberry transport vehicle can extend the fresh-keeping period of strawberries from 3 days to 5 days, significantly reducing losses during transportation.

IV. What Indicators Should Be Paid Attention to When Purchasing? How to Avoid Practical Pitfalls?

Faced with a wide range of Plasma Air Sterilizer products on the market, many consumers are confused by promotional slogans such as "high-efficiency disinfection", "no ozone", and "quiet operation", and may accidentally buy products that do not meet their needs or have potential safety hazards. In fact, there are clear "core indicators" and "pitfall avoidance points" for purchasing plasma air sterilizers. As long as you master this key information, you can easily select products with high cost-effectiveness and strong practicality.

First of all, authoritative testing certification is the "first threshold" for purchasing and the basis for ensuring the safety and effectiveness of the device. All regular plasma air sterilizers should pass the testing of internationally recognized third-party testing institutions (such as laboratories with ISO, ILAC, ANSI, CE, or other certifications) and provide a complete test report. These reports should clearly indicate the device's performance in key dimensions such as disinfection effectiveness, ozone emission, and energy consumption. Consumers can judge whether the device meets their actual needs through the report.

It is particularly important to note that the core feature of plasma air sterilizers is "no consumables", so compliant products should not be equipped with medium or high-efficiency filters (such as HEPA filters) inside. If a product claims to have "dual purification of plasma + HEPA", it essentially combines traditional filtration technology with plasma technology and is not a pure plasma sterilizer. This not only increases the cost of filter replacement in the later stage but may also affect the release efficiency of plasma due to filter blockage, which is a typical "concept confusion" trap that consumers need to be cautious of.

Secondly, quantified data on disinfection capability is the core basis for judging device performance. Do not be misled by vague statements such as "broad-spectrum disinfection" or "high-efficiency purification". In the test report of a regular product, the following data should be clearly marked: the disinfection rate for common bacteria (such as Staphylococcus albus, Escherichia coli, Staphylococcus aureus), the inactivation rate for viruses (such as H1N1 influenza virus, novel coronavirus), and the degradation efficiency for pollutants such as formaldehyde and TVOC.

According to international general standards, a qualified plasma air sterilizer should have a disinfection rate of no less than 90% for bacteria, an inactivation rate of no less than 90% for viruses, and a degradation rate of no less than 80% for formaldehyde. If the test report of a product does not mark specific values or the values are lower than the above standards, it is not recommended to purchase it even if the price is low. In addition, some merchants will provide "disinfection data in laboratory environments". Consumers need to note that the data in laboratory environments (where temperature, humidity, and initial pollutant concentration are all in ideal states) is usually higher than that in actual use scenarios. When purchasing, priority can be given to products marked with "test data in simulated actual use scenarios", which have higher reference value.

Ozone emission is a key indicator related to the safety of device use and must be strictly controlled. Although the ozone emission of compliant products will be controlled below the international general safety threshold, there are still differences in the actual ozone concentration of devices from different brands during operation. When purchasing, consumers can check the "ozone emission concentration" value in the test report and prioritize products with an actual measurement value lower than 0.10mg/m³ (the safe upper limit of indoor ozone in most regions of the world is 0.16mg/m³) for higher safety. In addition, some products will be marked with "non-toxic and no secondary pollution", but it should be noted that this statement needs to be supported by a test report. If the merchant cannot provide relevant proof, there may be a risk of false advertising.

To help readers quickly compare the differences between plasma air sterilizers and traditional purification devices, the following table summarizes their core characteristics:

Table 1 – Comparison of Core Characteristics: Plasma vs. Traditional Air Purification Devices

The matching degree between device parameters and space needs directly affects the purification effect and is also a common trap in purchasing. Many consumers may think that "the higher the device power, the better" or "the larger the applicable area, the better", but in fact, if the device parameters do not match the use space, it will not only cause waste but also affect the purification effect. For example, using a large device suitable for 100㎡ in a 10㎡ bedroom will result in excessive noise (the fan power of large devices is usually higher) and increased energy consumption; on the contrary, using a small device only suitable for 20㎡ in a 100㎡ living room will require the device to operate at full load continuously to barely maintain the air quality in a local area, which not only has low purification efficiency but also shortens the service life of the device.

When purchasing, focus on the matching relationship between the "applicable area" and "air volume" parameters. Generally speaking, the ratio of the applicable area (unit: ㎡) of the device to the air volume (unit: m³/h) should be controlled between 1:5 and 1:8. This ratio is derived from the international general standard that "air needs to circulate 5-8 times per hour to achieve effective purification". For specific calculation, the following example can be referred to: if the use space is 50㎡ with a floor height of 2.8m, the space volume is 140m³. If the air needs to circulate 5 times per hour, the required air volume is 700m³/h. However, in practice, the air volume marking of plasma devices is mostly directly related to the applicable area. Consumers can first refer to the "applicable area" parameter given by the manufacturer and then adjust it according to their own space. If the floor height of the space exceeds 3m (such as a loft apartment or factory building), the "actual volume = area × floor height" should be recalculated, and then the air volume should be selected accordingly. If the space has poor ventilation (such as a basement without windows or a closed office), the air circulation speed is slow, and the air volume needs to be increased by 20% to avoid pollutant accumulation. If the space is a newly renovated room with high concentrations of formaldehyde and TVOC (usually exceeding 0.3mg/m³), the air volume needs to be increased by 30% to ensure that the active particles can quickly degrade the pollutants.

In addition, operating noise is also an important indicator affecting the user experience, especially for scenarios that require a quiet environment such as bedrooms and studies. The operating noise of compliant plasma air sterilizers is usually controlled between 30-50 decibels: 30 decibels is equivalent to a quiet environment in a library, 40 decibels is close to a soft conversation, and 50 decibels is similar to the sound of normal indoor activities. When purchasing, in addition to checking the "noise value" in the test report, consumers can also judge through actual experience. If purchasing offline, they can ask the merchant to test the device and feel the noise within 1 meter of the operating device. If purchasing online, they can check the feedback on "noise" in user reviews and prioritize models that most users evaluate as "no interference during night use". Some high-end models are equipped with "intelligent noise reduction design", which reduces noise by optimizing the structure of the fan blades and adding sound insulation cotton. For example, in the "silent mode" of a certain model, the fan speed decreases from 2000 rpm to 1200 rpm, and the noise can be reduced from 45 decibels to 28 decibels, which does not affect sleep at all.

It is also necessary to be alert to "false advertising traps". In addition to "can remove PM2.5" and "can disinfect all viruses", common traps also include "zero ozone emission" and "no cleaning required". First of all, "zero ozone emission" does not conform to scientific principles - plasma technology will inevitably generate a small amount of ozone when producing active particles. Compliant products can control ozone within a safe range, but "zero ozone" is impossible. If a merchant uses this as a promotional point, it is likely that the data is not truly marked. Secondly, "no cleaning required" is also misleading - the electrodes will accumulate dust after long-term use. If not cleaned in time, the production of active particles will be reduced by more than 30%, and the purification effect will be significantly reduced. Therefore, the promotion of "no cleaning required" is not credible. If consumers find that a merchant has false advertising, they can ask for the corresponding test report. If it cannot be provided, they should decisively give up purchasing.

V. How to Maintain It in Daily Use? How to Solve Common Faults?

The correct maintenance method is the key to ensuring the long-term stable operation of the Plasma Air Sterilizer, and its maintenance process is much simpler than that of traditional devices, which can be operated without professional skills. However, the maintenance focus varies slightly in different use scenarios.

(I) Daily Maintenance: Scenario-Specific Operations to Extend Device Life

1. Basic Cleaning: Fixed Weekly and Quarterly Procedures

The outer shell cleaning is recommended to be carried out once a week, and the cleaning methods for outer shells of different materials are slightly different: the plastic outer shell can be directly wiped with a damp cloth. If there is oil stain (such as for devices used in the kitchen), a small amount of neutral detergent can be dipped for wiping, and then dried with a dry cloth. For metal outer shells (such as stainless steel), hard rags should be avoided to prevent scratching the surface. Microfiber cloths can be used. After cleaning, a small amount of anti-rust oil can be applied once a year to prevent oxidation. The power must be disconnected during cleaning. If the device has just been running, wait for the outer shell to cool down to room temperature (usually 10-15 minutes) before cleaning to avoid scalding.

The internal cleaning should be carried out once a quarter, focusing on cleaning the electrodes and emitters. The specific steps are as follows:

① Disconnect the power supply and wait for the device to cool down;

② Find the panel buckles (usually on both sides or the top of the device), gently open them with your fingers, and remove the panel;

③ Observe the surface of the electrodes: if only a small amount of dust is attached, gently brush it off along the direction of the electrodes with a dry soft brush (such as a toothbrush or a special cleaning brush), and avoid lateral force to prevent the electrodes from deforming; if there is oil stain or stubborn dirt (such as devices used in the kitchen or workshop), dip the brush in a small amount of pure water (do not dip in detergent), wring it dry, and gently wipe it. After wiping, use a dry cloth to absorb the moisture;

④ After cleaning, place the panel in a ventilated place to dry (about 30 minutes), then install it back on the device, and ensure that the buckles are fully fastened to avoid noise caused by loose panels during operation.

2. Special Scenario Maintenance: Targeting High-Pollution and Humid Environments

For devices used in high-pollution environments (such as kitchens, workshops, and newly renovated rooms), the maintenance frequency needs to be appropriately increased: the outer shell cleaning can be changed to once every 3 days, and the internal cleaning can be changed to once every 2 months. At the same time, check the primary filter (if any): if the filter is covered with a lot of dust, remove it and rinse it with clean water (confirm that the filter is washable), and reinstall it after drying. If the filter is damaged, replace it in time (the price of primary filters is relatively low, usually 10-20 each, and can be prepared in advance).

For devices used in humid environments (such as bathrooms and basements), additional moisture-proof measures are required: place a moisture-proof pad (such as a silica gel moisture-proof pad) under the device to prevent moisture from the ground from entering the device; open the panel once a month and wipe the moisture on the surface of the internal components with a dry cloth. If the electrodes show signs of rust, apply a small amount of conductive paste (special conductive paste for plasma devices should be selected and can be purchased from the manufacturer's after-sales service) to prevent corrosion from affecting the conductive performance. When the device is not in use for a long time, move it to a dry environment for storage, and turn it on for 30 minutes regularly (every 2 months) to prevent the internal components from aging due to moisture.

3. Annual Comprehensive Inspection: Combining Independent Inspection and Professional Maintenance

Although plasma devices do not require consumable replacement, it is recommended to conduct a comprehensive inspection once a year, which can combine independent inspection and professional maintenance:

• For the independent inspection part: Check whether the power cord is damaged and whether the plug is oxidized (if oxidized, gently polish it with fine sandpaper); check whether the heat dissipation holes at the bottom of the device are blocked (use the small suction head of a vacuum cleaner to clean the dust); test whether each function button is normal (such as power on/off, air volume adjustment, and mode switching);
• For the professional maintenance part: Contact the manufacturer's after-sales service to request on-site inspection of the electrode performance (such as whether the electrode spacing is normal and whether the discharge is stable) and calibration of the sensor (if any). Some brands provide free annual inspection services, and consumers can consult in advance.
  
  

(II) Common Faults: Troubleshooting by Situation with Emergency Handling

When a device fault occurs, there is no need to contact after-sales service in a hurry. You can first troubleshoot according to the following steps. Most minor faults can be solved quickly. If the fault cannot be solved after troubleshooting, then contact professional maintenance.

Fault 1: The Device Cannot Be Started (with Emergency Handling)

In addition to checking the power cord and child lock function, the following situations should also be considered:

• If the device is equipped with an "overheat protection" function (most models have this function), when the internal temperature of the device exceeds 60°C, it will automatically shut down for protection. In this case, wait for the device to cool down for 30 minutes before trying to start it again;
• If the device has been used for more than 5 years, the power adapter may be faulty (only applicable to desktop models). You can replace it with a power adapter of the same specification (note that the voltage and current are consistent with the original one, such as 12V/2A) for testing. If the device can be started after replacement, the power adapter needs to be replaced;
• Emergency handling: If the device is urgently needed, first check whether it is a simple fault (such as a loose power cord). If it cannot be solved, a backup air purification device (such as a small HEPA purifier) can be used temporarily to avoid the impact of poor air quality on health.
  
  

Fault 2: The Indicator Light Does Not Light Up (Solution by Type)

The indicator light not lighting up is divided into "single indicator light not lighting up" and "all indicator lights not lighting up":

• Single indicator light not lighting up (such as the "silent mode" indicator light): This is mostly due to the damage of the indicator bulb, which does not affect the device function and can continue to be used. If replacement is needed, contact the manufacturer's after-sales service to purchase a bulb of the corresponding model (usually an LED bulb with a low price). When replacing by yourself, disconnect the power supply, disassemble the indicator panel with a screwdriver, remove the old bulb, and install the new bulb;
• All indicator lights not lighting up: In addition to power supply problems, it may also be a fault of the internal circuit board. Do not disassemble the device by yourself at this time. Record the device model, purchase time, and fault phenomenon, and contact the manufacturer's after-sales service to provide relevant information to facilitate the maintenance personnel to quickly locate the problem.
  
  

Fault 3: The Purification Effect Decreases (with Detection Method)

In addition to cleaning the electrodes and filters, it is also necessary to detect whether the purification effect has really decreased to avoid subjective judgment errors:

• Detection method: A household air quality detector (such as a detector for TVOC and bacterial colony count) can be used to detect before and after the device is running. If the TVOC concentration decreases by less than 50% and the bacterial colony count decreases by less than 60% 1 hour after running, it is confirmed that the purification effect has decreased;
• Additional troubleshooting: If the device has been used for more than 3 years, the electrodes may be aging (such as severe corrosion on the electrode surface). At this time, the electrodes need to be replaced. Contact the manufacturer's after-sales service to purchase original electrodes. When replacing, follow the steps in the instruction manual to ensure that the electrode spacing meets the requirements (usually 2-3mm) to avoid affecting the discharge effect due to too large or too small spacing.
  
  

Fault 4: Abnormal Operating Noise (with Temporary Handling)

In addition to the basic placement and foreign object inspection, the following points should also be considered:

• If the noise is a "friction sound", it may be that the fan bearing is short of oil. At this time, contact the after-sales service to add special lubricating oil. Do not add ordinary engine oil by yourself to avoid damaging the fan;

If the noise is a "vibration sound", it may be that the internal parts of the device are loose (such as loose fan fixing screws). After disconnecting the power supply, open the panel and tighten the loose screws with a screwdriver, then test whether the vibration sound still exists;

• Temporary handling: If maintenance cannot be carried out immediately, the device can be moved to a non-rest area (such as a balcony or storage room) for use to avoid noise affecting life. At the same time, reduce the air volume to reduce noise.

It is particularly important to remind that if the device has serious faults such as "smoke", "burnt smell", or "abnormal sparks", in addition to disconnecting the power supply immediately, the following measures should also be taken: cover the device with a dry towel (if there is slight smoke) to prevent the spread of fire; record the situation when the fault occurred (such as whether a specific function was being used and whether there was a precursor of peculiar smell) to facilitate the maintenance personnel to analyze the cause; do not approach the faulty device to avoid electric shock or burns. After the device has completely cooled down, contact the manufacturer's after-sales service for handling.

VI. How to Choose Targeted Products for Different Groups? How to Meet Specific Needs?

Different groups have significant differences in usage scenarios and core needs. Blind purchasing may result in devices that fail to match actual requirements. The following provides targeted purchasing suggestions for several typical groups, and the table below further summarizes the key points for quick reference.

Table 2 – Targeted Purchasing Guide for Different Groups

(I) Families with Infants and the Elderly: Prioritize Safety and Convenience

Infants have delicate respiratory mucosa, and the elderly have weak immunity, so they have higher requirements for the safety and operational convenience of devices. When purchasing, focus on three points:

• Ozone control accuracy: Prioritize models with ozone emissions below 0.08mg/m³ (far below the international safety threshold) to avoid irritating infants' respiratory tracts. Check the "long-term operation ozone concentration" data in the test report to ensure that the ozone concentration remains within a safe range after the device operates continuously for 24 hours;
• Simplified operation design: Choose models equipped with "one-click start" and "child lock function" – infants may accidentally touch the device buttons, and the child lock function can prevent accidental shutdown or mode switching; the elderly may be confused by complex button designs, and one-click start can simplify the usage process;
• Size and placement: Prioritize small desktop models (with a height of no more than 50cm), which can be placed at a height out of infants' reach (such as a bedside table or bookshelf) to avoid collision and tipping; some models are equipped with anti-slip pads at the bottom, which can reduce the risk of accidental sliding and are more suitable for families with toddlers.
  
  

(II) People with Allergies: Focus on Disinfection and Pollutant Degradation

People with allergies (such as pollen allergies and dust mite allergies) need to pay attention to the device's ability to handle allergens in addition to disinfecting bacteria and viruses. When purchasing, note:

• Broad-spectrum disinfection range: Check the "dust mite allergen removal rate" and "pollen disinfection rate" data in the test report. Prioritize models with a dust mite allergen removal rate of over 85% and a pollen disinfection rate of over 90% to reduce symptoms such as sneezing and skin itching caused by allergens;
• No secondary pollution design: Avoid models with primary filters (filters are prone to accumulating dust mites and pollen, which may cause secondary pollution if not cleaned in time). Pure plasma technology models do not require filters and only need regular electrode cleaning, which can reduce allergen residues from the source;
• Timer function: Choose models with "scheduled on/off" function, which can be set to "automatically shut down after 4 hours of operation" before going to bed. This not only ensures air quality at night but also avoids slight noise from long-term operation of the device affecting sleep (people with allergies are often sensitive to the sleeping environment).
  
  

(III) Office Workers/Renters: Balance Portability and Space Adaptability

Office workers may use the device alternately in the office and at home, and renters have variable living spaces, so the device needs to be portable and flexible. When purchasing, focus on:

• Lightweight and portability: Choose models weighing less than 3kg (equivalent to the weight of a laptop), with a handle design being better for easy movement between the office, bedroom, and living room; some models support USB power supply (voltage compatibility needs to be confirmed), which can be connected to a computer or power bank for temporary use, suitable for placing on the desk during overtime work;
• Multi-scenario modes: Choose models with dual modes of "office mode" and "sleep mode" – switch to "office mode" during work, with moderate air volume (about 300m³/h), which can purify the air without interfering with colleagues' conversations; switch to "sleep mode" at night, with noise reduced to below 30 decibels, which does not affect rest;
• Space adaptability: Rental spaces are mostly small (10-30㎡), so models suitable for 15-40㎡ are sufficient to avoid large-sized devices occupying too much space; some models can be wall-mounted (check whether installation accessories are included), which can save desktop or floor space and are suitable for narrow rental houses.
  
  

(IV) Food Industry Practitioners/Laboratory Staff: Focus on Professional Disinfection and Compliance

Food processing stores (such as bakeries and milk tea shops) and laboratory staff have higher requirements for the professional disinfection performance and industry compliance of devices, which need to match the hygiene standards of specific scenarios. When purchasing, note:

• Industry testing certifications: Prioritize models that have passed food industry-specific tests (such as "food contact surface microbial disinfection certification") and laboratory safety certifications (such as "chemical laboratory organic pollutant degradation certification") to ensure the device meets industry hygiene standards;
• Corrosion-resistant materials: Food processing environments may have oil and sugar residues, and laboratories may come into contact with chemical reagents. Choose models with 304 stainless steel shells (corrosion-resistant and easy to clean) to avoid plastic shells being corroded by chemical reagents or difficult to clean due to oil adhesion;
• Continuous operation stability: Food processing stores require the device to operate for 8-12 hours a day, and laboratories may need 24-hour continuous operation. When purchasing, check the "performance attenuation rate after 1000 hours of continuous operation" in the test report. Prioritize models with an attenuation rate of less than 10% to ensure long-term stable disinfection effects.
  
  

VII. What Other Safety Precautions Are There During Use? How to Avoid Potential Risks?

Correct use is the key to ensuring device safety. In addition to daily maintenance, attention should also be paid to potential risks in the use scenario to avoid safety issues or reduced device life due to improper operation.

(I) Usage Environment Taboos: Scenarios Where Placement Is Prohibited

• Near water sources: Do not place the device near sinks, fish tanks, or humidifiers (at least 1.5 meters away from water sources). Moisture entering the device may cause short circuits and electric shock risks; if used in the kitchen, avoid soup or oil splashing onto the device, and ensure the device is completely powered off during cleaning;
• High-temperature and high-humidity environments: Do not use the device in high-temperature and high-humidity environments (temperature exceeding 40°C and humidity exceeding 80%) such as bathrooms and saunas. High temperatures will accelerate electrode aging, and high humidity may cause rusting of internal components, shortening the device's service life; when used in humid environments such as basements, a dehumidifier should be used together to control the environmental humidity below 60%;
• Near flammable items: Do not place the device near flammable items such as alcohol, gasoline, and perfume (at least 2 meters away). The trace sparks generated by the electrodes during device operation (a normal phenomenon) may cause fires if they come into contact with flammable gases; when used in laboratories, keep it away from chemical reagent storage cabinets to avoid adverse reactions between volatile reagent gases and the device.
  
  

(II) Operational Safety: Prohibited Behaviors

• Unauthorized disassembly and maintenance: The device contains high-voltage circuits (with voltages up to several thousand volts), so non-professionals are prohibited from disassembling it – even if the device fails to start, contact the manufacturer's after-sales service for maintenance. Unauthorized disassembly may lead to electric shock; some manufacturers provide "on-site maintenance services", which can avoid the trouble and risk of transporting the device by yourself;
• Blocking the device's air outlet: During device operation, the air outlet must remain unobstructed (at least 30cm away from obstacles). Do not cover the air outlet with cloth or paper, otherwise, the internal temperature of the device will rise, triggering overheat protection and shutdown. Long-term blocking may burn the fan;
• Children operating alone: Children under 12 years old are prohibited from operating the device alone. Children may accidentally touch the "high-voltage mode" or "air volume adjustment" buttons, causing abnormal device operation; if the device has no child lock function, place it at a height out of children's reach to avoid accidental operation.
  
  

(III) Handling of Special Situations: How to Respond to Emergencies

• Restart after power outage: In case of a sudden power outage, first disconnect the device's power supply. After power is restored, wait for 5 minutes before restarting – after a sudden power outage, the internal capacitor of the device may still have residual charge, and immediate startup may cause circuit impact and shorten the service life;
• Handling of abnormal odors: If the device emits a "burnt smell" or "plastic smell" (not the smell of ozone) during operation, immediately power it off and check: if it is a new device, a slight plastic smell may occur during the first operation (a normal phenomenon, which will disappear after 30 minutes of ventilation); if it has been used for more than 6 months, the electrodes may be overheated due to excessive dirt accumulation, so clean the electrodes before trying to start it again;
• Moving the device: Always disconnect the power supply before moving the device, and do not move it with power on – pulling the power cord of the device may cause loose plugs or damaged wires, leading to electric shock; when moving, hold the bottom of the device with both hands to avoid tilting the device and displacing internal components.
  
  

VIII. Conclusion: Choose Rationally to Let the "Air Guardian" Truly Deliver Value

With practical advantages such as no consumables, coexistence with humans, and full-space purification, Plasma Air Sterilizers demonstrate important value in the medical, public health, food, and pharmaceutical fields – in hospital operating rooms, they can work with laminar flow systems to maintain air cleanliness at the "sterile level" and reduce surgical infection rates; in school classrooms, they can operate 24 hours a day to reduce the spread of infectious diseases such as influenza; in food processing workshops, they can disinfect microorganisms without chemical residues to ensure food safety; at the same time, they have gradually become an important guarantee for home air safety, especially suitable for families with the elderly, children, and people with allergies.

However, consumers should remain rational when choosing and clarify their core needs to avoid blind following:

• If the core need is "disinfecting bacteria and viruses + degrading formaldehyde", and long-term use costs (no consumables) and convenience (coexistence with humans) are expected, plasma devices are an ideal choice;
• If the core need is "removing PM2.5 + dust", such as in areas with severe smog or families with people allergic to dust, HEPA filter purifiers are more suitable. If disinfection is also needed, "HEPA + plasma" two-in-one models can be chosen, but attention should be paid to the cost of replacing HEPA filters in the later stage;
• If the core need is "large-area rapid disinfection", such as in shopping malls, airports, and other public places, commercial-grade plasma devices can be chosen. These devices usually have large air volume and high disinfection rates, and can be used with central air conditioning to achieve full-space purification.
  
  

When purchasing, focus on authoritative test reports (such as those from laboratories with ISO or ILAC certification), quantified disinfection data (such as 99.9% bacterial disinfection rate and 91% formaldehyde degradation rate), ozone emission (safer if below 0.10mg/m³), and operating noise (below 40 decibels is more suitable for home use). Avoid false advertising traps such as "zero ozone", "no cleaning required", and "disinfecting all viruses"; during daily use, perform maintenance according to the usage scenario (such as increasing cleaning frequency in high-pollution environments and taking moisture-proof measures in humid environments). When faults occur, first troubleshoot by yourself, and contact professional maintenance if they cannot be resolved.

Only by accurately matching device characteristics with actual needs and performing daily maintenance well can Plasma Air Sterilizers, the "invisible air guardians", truly deliver value, protect air quality in different scenarios, and allow people to live, work, and study in clean and safe air.