Does the air volume in the chemical filter quotation include all modules?

When receiving a quote for a chemical filter, the air volume column is often confusing: Is this number the air volume of a single module, or is it the air volume processed by the entire system?

Direct answer: The air volume caliber in the quotation must be clearly stated on the quotation. If you only write a number and do not indicate whether it is a single module or a complete set, the purchaser cannot judge whether it can cover the project requirements. What's more troublesome is that if you estimate the entire set of capabilities based on the air volume of a single module, the actual processing capacity may be seriously overestimated.

Distinguish between single unit and complete set

There are two common calibers of air volume in quotations.

Rated air volume of a single module. This is the air flow rate of a single filter module under specific test conditions, usually corresponding to a certain size, media and pressure loss conditions. The air volume marked on the sample is mostly like this.

The whole set of design processing capacity. This is the air volume that the entire filter section can handle after multiple modules are combined. It depends on the number of modules, series-parallel relationship, frame layout and actual air volume distribution.

The two cannot be confused. A quotation reads 'air volume 2000 m³/h'. If this is single module data and the system needs to handle 8000 m³/h, then 4 modules are needed; if this is a complete set of data, it directly corresponds to the system requirements. Different calibers lead to completely different conclusions.

For specific air volume selection methods, please refer to Discussion on whether the chemical filter air volume should be selected based on the total air volume of the system or the air volume of a single unit .

Check series and parallel structures

How the modules are connected determines whether the air volumes are added or shared.

tandem structure. When multiple filter sections are connected in series, all air volume passes through each section in sequence. Series connection does not increase the processing air volume, and each section bears the same system air volume. For example, for a two-stage chemical filtration section connected in series, each stage must be able to pass the total air volume of the system.

Parallel structure. When multiple modules are connected in parallel, the total air volume is distributed to each module. Each module bears a portion of the air volume. The total processing capacity is the sum of the air volume of each module, but the premise is that the air volume is evenly distributed.

Series and parallel combination. Some systems have both series and parallel connections. It needs to be confirmed in sections: how much air volume passes through each section and how much each module bears.

The connection method should be specified in the quotation. If only the number of modules is written without explanation of series and parallel connections, the purchaser cannot judge the actual capability.

Check module quantity and allocation

Even if the parallel structure is clear, the actual air volume distribution may not be uniform.

Difference in branch resistance. The length of the branches connected to each module, the number of elbows, and the position of the air valve may be different. For branches with high resistance, the air volume may be small.

Inlet air distribution. If multiple modules are installed in a large frame, the location of the air inlets will affect the airflow distribution. The air volume of modules close to the air inlet may be larger, while that of modules farther away may be smaller.

Maintenance status. If a module's filter material has been consumed or clogged, its resistance changes may cause air flow to be redistributed.

Therefore, the air volume of a single module cannot be estimated simply based on 'total air volume ÷ number of modules'. Actual distribution requires on-site measurement confirmation.

For specific balancing methods, please refer to whether chemical filtration modification requires re-doing the air volume balance . Discuss

Confirm performance and interface range

The air volume in the quotation must also be checked with the performance and interface.

The efficiency or capacity corresponding to the air volume. The air volume data should correspond to the efficiency, capacity or penetration data of the target gas. The air volume separated from the performance is just an airflow parameter and cannot explain the treatment effect. For specific reporting requirements, please refer to Discussion of why chemical filter performance reports list specific target gases .

The resistance corresponding to the air volume. Air volume usually comes in pairs with resistance. The initial resistance and final resistance at the air volume should be indicated in the quotation to facilitate calculation of the fan operating point. For specific calculations, please refer to Discussion of how much the added resistance of the chemical filter will increase the fan's electricity consumption .

Interface size. The module size, interface form, and sealing method corresponding to the air volume need to match the on-site installation frame. For specific matching methods, please refer to Discussion of how chemical filter sizes match existing filter frames .

Maintain space. When the number of modules is large, the passage and operating space for replacing filter media must be confirmed in advance. For specific measurements, please refer to Discussion of what dimensions should be covered in chemical filtration retrofit field measurements .

Project judgment example

A certain project received a quotation for chemical filters, which stated 'air volume 4000 m³/h, quantity 4 units'.

The purchaser initially believes that the total air volume of 4 units is 16,000 m³/h, which meets the system requirements. However, after careful inspection, we found that this 4000 m³/h is the rated air volume of a single module, and the modules are connected in series. When connected in series, each unit passes the total air volume of the system, and the processing volume cannot be added. The actual total system air volume needs to be checked based on the air volume of a single module, rather than multiplied by 4.

After clarifying the specifications, the supplier re-provided the entire set of designed processing capacity, and noted the series-parallel connection method and air volume distribution. The purchaser adjusted the selection plan accordingly.

The quotation of another project stated 'processing air volume 8000 m³/h', without specifying whether it was a single unit or a complete set. The purchaser requires the supplier to provide additional explanations, confirm that it is a complete set of data, and check the module quantity and distribution method.

These two cases illustrate that the air volume caliber in the quotation must be clear and cannot be relied on guesswork. involving When selecting chemical filter product series , it is recommended to provide the system air volume, module requirements and connection methods to the supplier for verification.

Key points for selection and acceptance inspection

About Aili Industrial’s quotation package

Aili Industrial has independent manufacturing capabilities in filters, motors, fans, control systems and sheet metal processing, and can provide chemical filter product series and supporting air supply equipment. When quoting, you can indicate the air volume caliber, module quantity, series and parallel connection method and air volume distribution according to the project requirements to facilitate the purchaser's verification.

Related products:Chemical filter product series、MAU box chemical filter、FFU comes with chemical filter . Providing system air volume and module requirements when inquiring will help obtain a clear quotation. The specific selection is subject to the technical documents and test results confirmed by the project.