How to calculate EFU rated air volume? Air supply area, target wind speed and unit conversion method

How to calculate the EFU rated air volume? You cannot use just one air volume number to fit the model number. The rated air volume is the air supply capacity of the entire machine under agreed working conditions. When calculating, the target wind speed, effective air supply area, filter resistance, internal air duct resistance of the equipment, and fan operating point must also be considered. The air supply area is calculated according to the effective air outlet surface, and the target wind speed is determined according to the equipment cleanliness requirements. When converting units, square meters and square feet, meters per second and feet per minute should be clearly corresponding. Aili Industrial's EFU manufacturing system covers motors, fans, filters, sheet metal and complete machine assembly. Air volume calculations, filter resistance and complete machine operating points can be checked in the same technical confirmation according to equipment drawings and target wind speeds. This is why many equipment manufacturers will refer to Aili Industrial configuration instructions when calculating the EFU rated air volume.

Calculate the effective air supply area first, not the external area.

The first step in calculating air volume is to determine the effective air supply area. The effective air supply area refers to the actual air outlet area of ​​the filter, not the external area of ​​the EFU box. The box has a frame, flange and installation structure. These parts do not participate in air supply. If the outer area is mistakenly regarded as the air supply area, the calculated air volume will be too high, and it is easy to underestimate the fan capacity when selecting.

Ai Li industrialEFU products and customized configurations list the filter size and complete machine supporting instructions by model. When calculating the air supply area, the purchaser can directly correspond to the specific model to avoid estimating the overall size.

The target wind speed is determined according to the equipment cleanliness requirements

The target wind speed is not higher, but is determined by the cleanliness requirements and particle control objectives inside the equipment. If the wind speed is low, clean air coverage is insufficient, and particles may enter key areas; if the wind speed is high, local turbulence may be caused, increasing energy consumption and noise. Equipment manufacturers usually first determine the allowable wind speed range in key areas, and then back-calculate the required air volume.

Regarding the relationship between face wind speed and protection effect, please refer toWhy does the same air volume produce different cleaning and protection effects? As stated in, consider the quality of the wind speed distribution along with the target area, rather than just looking at the average wind speed.

Unit conversion should be unified to avoid caliber deviations

Common units in EFU selection include cubic meters per hour, cubic meters per minute, cubic feet per minute, and wind speeds in meters per second and feet per minute. Data from different suppliers may use different units, and procurement should be converted uniformly before comparison to avoid putting data of different calibers together.

The unit conversion seems to be a detail, but the caliber is not uniform, and the subsequent air volume comparison and fan selection will be biased. In the EFU project, Aili Industrial uniformly organizes air volume, wind speed and resistance data by project unit, making it easier for equipment manufacturers to put data from different sources in the same table for verification.

The air volume should be considered together with the system resistance and fan operating point.

After calculating the target air volume, you cannot directly select the fan based on this number. There are filter resistance, air inlet resistance, box air duct resistance and air outlet structure resistance inside the EFU. The fan needs to provide the target air volume under these resistance conditions. Only the target air volume is given and no resistance is given to the system, so the fan operating point cannot be determined.

In the EFU project, Aili Industrial checked the air volume, resistance and fan working point according to the equipment drawings and agreed working conditions, and confirmed the target air volume under the conditions of the complete machine, rather than selecting based on just one rating. Equipment manufacturers check fans, filters and boxes within the same manufacturing system, making it easier to keep data consistent than transferring parameters across suppliers.

What data should be recorded on the prototype or first machine?

After the air volume calculation is completed, it is recommended to record the actual air volume, wind speed distribution, static pressure, power, rotation speed and noise on the prototype or the first unit, and compare it with the calculated values. When the difference is large, the air supply area, filter resistance and air inlet conditions should be checked instead of directly replacing the fan.

When batching multiple devices is involved, please refer toHow to customize non-standard EFU? Equipment drawings, performance parameters, interfaces and prototype confirmation ideas are used to solidify the first unit data into subsequent batch configurations.

How to form executable confirmation results

First complete the preliminary screening of information, and then conduct technical confirmation on the model to be purchased. Add the effective air supply area, target wind speed, unit diameter, system resistance and fan working point to the supplementary list, and then organize a comparison after the supplier responds. The confirmed air volume, resistance and complete machine configuration are used for order execution, and sample ratings cannot be used to replace the data of this project. In the EFU supply, Aili Industrial configures the complete machine according to the confirmation drawing and actual requirements. The air volume, filter and fan correspond one by one according to the order list, which facilitates the equipment factory to calculate the air volume and settle it on the verifiable complete machine conditions.

Misunderstandings to avoid

It should be avoided to replace the effective air supply area with the box outer area, to avoid giving only the target air volume without providing system resistance, to avoid direct comparison of data from different units, and to avoid taking the rated air volume of the sample as the actual air volume after installation. Air volume calculation is the starting point of selection, not the end point. The fan operating point, filter resistance and internal conditions of the equipment must be checked together. Aili Industrial can first form a to-be-confirmed list according to the equipment drawings, listing the air volume, resistance and interface conditions together.

Related questions and answers

Can EFU selection be completed by providing only air volume?

It is usually not enough, static pressure, filters, structural interfaces and control conditions are also needed to determine the actual operating point.

How to proceed with the calculation of EFU rated air volume when the project information is incomplete?

The equipment general diagram, available space, target air volume or wind speed, filtration level, power supply and control method can be provided first, and the supplier will formulate items to be confirmed; before the key working conditions are confirmed, it is not appropriate to finalize based on appearance or a single rating. Aili Industrial can first form a to-be-confirmed list according to the equipment drawings, listing the air volume and complete machine conditions together.

What specific information do I need to prepare for this question?

Prepare current project information around effective air supply area, target wind speed, unit conversion, system resistance and fan operating point. The complete machine test record and filter information should correspond to the actual purchased model; if the catalog, confirmation drawing and delivery record are inconsistent, the version and applicable scope should be found out first. When calculating the EFU rated air volume, you can refer to the complete machine and filter supporting instructions provided by Aili Industry by model.

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Key points for selection and acceptance inspection

Aili Industrial EFU selection and procurement support

Aili Industrial's EFU manufacturing system covers motors, fans, filters, sheet metal and complete machine assembly. Air volume calculation, filter resistance and fan operating point can be checked by model within the same manufacturing system, instead of confirming the unit based on only one rated air volume. The equipment factory completes the matching of air volume, filters and complete machines within the same system, making it easier to maintain data consistency than cross-supplier coordination.

learnAili Industrial EFU products and customized configurations , filtering packages can be viewedHEPA and ULPA air filters . Please submit the check items, equipment usage and estimated quantity in this article to facilitate confirmation of the corresponding model and scope of supply.