The impact of chemical filters on night duty air supply costs needs to be evaluated based on the duty air volume, fan efficiency, pollution load and operating requirements. Reducing the air supply may reduce some electricity usage, but it cannot be assumed that gas control and room status are always unaffected. Part of the electricity bill saved at night may become the cost of adjusting the machine during the day.

Night load is not a simple matter of 'no pollution if there is no one'

Many projects default to no one at night and the pollution load returns to zero, so the air volume is reduced to the minimum. This assumption holds true in some scenarios and not in others. Material outgassing, equipment standby release, external fresh air input and adjacent area infiltration will not stop automatically at night. The residual solvent after cleaning may continue to evaporate, and the wafers in the FOUP or carrier are still being released. The concentration of outdoor traffic or industrial emissions is sometimes higher at night. When setting the duty air volume, you should first confirm which pollution sources are at work at night, rather than just deciding based on the number of personnel.

The decrease in air volume affects the system status and not just the electricity bill

Reducing the air supply volume directly reduces the fan power consumption, but at the same time changes the room pressure difference, airflow organization and filter section flux. Changes in pressure difference may change the direction of air flow in adjacent areas. Changes in air flow organization may cause stagnant areas to appear in certain work stations. Although the decrease in filter section flux reduces resistance, it also changes the contact conditions between gas and medium. These changes may not be noticeable at night and are not revealed until full capacity is restored during the day. The evaluation of duty mode should look at differential pressure, airflow and gas control together, rather than just comparing fan power.

The filter section resistance and fan curve determine the actual power saving

How much electricity can be saved by reducing air flow at night depends on the type of fan and the resistance characteristics of the filter section. The power of centrifugal fans drops quickly when the speed is reduced, and the efficiency of EC fans also differs in the low-speed section. The extent to which the resistance of the filter section decreases with the air volume is related to the media structure. For the same air volume reduction, the corresponding power savings on different systems may vary greatly. To get a reliable estimate, take power measurements at actual air volumes rather than multiplying the rated power by the air volume ratio. Regarding the adjustment of EC fans and chemical filtration, please refer toCan chemical filters be paired with EC fans to improve operational regulation?。

Filter element consumption is not shortened in proportion to operating hours.

When the air volume decreases at night, the cumulative gas processing capacity of the filter element may decrease, but the replacement cycle may not necessarily be extended in proportion to the operating hours. If there is still material outgassing and external input at night, the medium is still consuming capacity; during shutdown, the filter section is in contact with contaminated air, and it may continue to be consumed. In addition, if there is a dead spot in the airflow distribution at low air volume at night, local media may penetrate early. Maintenance arrangements in duty mode should be adjusted based on outlet detection trends, rather than simply calculating lifespan based on air volume ratio. Regarding the replacement cycle issue under intermittent operation, please refer toHow to calculate the replacement period for a chemical filter that operates intermittently? Is downtime included?。

Aili industrial supporting equipment

For needs such as night duty air supply, we usually first ask what other pollution sources are at night, what the pressure difference requirements are, and whether the distribution of filter sections is even under low air volume, and then talk about energy-saving space. Aili Industry can provide selection packages for box-type, flat-plate and V-type chemical filtration products. For box-type MAU packages, please refer toMAU box type chemical filter , product series can be viewedChemical filter product range . The V-shaped structure provides a larger filtration area in the same box space, and the surface speed is lower during low air volume operation, helping to maintain contact time. Equipment-side applications can adopt the form of chemical filtration FFU, integrating chemical adsorption layer and HEPA/ULPA particle filtration. The manufacturing end covers independent R&D and production of motors and fans, control systems, sheet metal and complete machine assembly. The duty air volume setting, fan speed regulation and filter section resistance can be checked in the same package. The specific gas effect, energy consumption data and replacement cycle still need to be verified based on the corresponding configuration data and on-site working conditions. The actual results are subject to on-site leak detection and gas detection results.

Related questions and answers

Will reducing the air volume to very low at night affect gas control?
Depends on nighttime pollution sources and pressure differential requirements. Material outgassing and external input will not stop due to no one. Before reducing the air volume, it should be confirmed that the key areas can still meet the gas and pressure difference conditions.

How much power can the duty mode save?
It is related to the fan type, filter section resistance and actual air volume drop. It should be estimated using the measured power data, and cannot be calculated proportionally using only the rated power.

Can Aili Industrial help check the duty operation plan?
Combining the nighttime pollution load, pressure difference requirements and fan characteristics, the match between the air volume on duty and the flux of the filter section can be checked. The specific plan needs to be confirmed based on site conditions and product data.

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Key points for selection and acceptance inspection