What is the difference between plate and bag filters used in air conditioning boxes?

The differences between plate and bag filters are mainly in structure, effective filtration area, installation depth and maintenance methods. Efficiency cannot be determined based on appearance alone. When selecting, the resistance, dust holding capacity, size and air flow conditions should be compared under the same rated air volume and clear evaluation level.

Let the installation frame and filter material enter the comparison table together

The plate type usually has a compact structure and is suitable for locations with limited depth; the bag type requires corresponding expansion space, and the bag body must be prevented from being squeezed by adjacent components during operation. Actual products have different filter media, number of bags, support and sealing designs, and their performance will also be different. One sample performance of one type of structure cannot be applied to all models.

The space conditions should include the outer frame size, installation depth, bag expansion and extraction path; the performance conditions should include the level, initial resistance and related performance data under the same air volume; the maintenance conditions should include replaceability, pressure difference monitoring and post-use disposal methods. The three items correspond to different selection links, and you cannot just compare appearance. How to configure the primary and medium-efficiency filters in the air-conditioning box in different grades, please refer toHow to configure the primary-efficiency and medium-efficiency filters of air-conditioning boxes in different stages?。

Structural features of plate filter

Plate filters usually consist of an outer frame and pleated or flat filter media, with compact structure and small thickness. It is suitable for occasions with limited installation space. The extraction direction is direct when replacing, and maintenance is relatively simple. The effective filtration area of ​​a plate filter is limited by the size of the outer frame, and the dust holding capacity may be lower than that of a bag filter of the same size.

Plate filters are often used for primary filtration or intermediate filtration with limited space. How to select the filter level according to the inlet air conditions, please refer toHow to select the air conditioning box filter grade based on the inlet air conditions? . What needs to be considered when arranging the filter section before and after the fan? Please refer toWhat needs to be considered when arranging the filter section before and after the fan?。

Structural features of bag filters

The bag filter consists of an outer frame and multiple filter bags. The filter bags are unfolded in the direction of air flow, and the effective filtration area is larger than that of a plate filter of the same size. A larger filter area usually brings lower surface velocity and higher dust holding capacity, but requires sufficient installation depth to accommodate the expansion of the bag. The bag body cannot come into contact with or be squeezed by adjacent parts during operation.

Bag filters are often used in medium-efficiency filtration or situations where higher dust holding capacity is required. The number of bags, bag length and bag body shape will affect the resistance and dust holding capacity. When the installation depth is insufficient, the bag body may be deformed or damaged, affecting the filtration effect. The filter grade and evaluation system must be unified, please refer toHow to select the air conditioning box filter grade based on the inlet air conditions?。

Resistance and dust holding capacity should be compared under the same air volume

The initial resistance of plate and bag filters may be different, and the resistance rising speed after dust collection is also different. The bag filter has a larger effective area, lower surface velocity, lower initial resistance, and higher dust holding capacity; plate filter has a compact structure, but the surface velocity may be higher. When comparing, the resistance curve and dust holding data should be viewed under the same rated air volume and the same evaluation level.

How to calculate the filter resistance into the internal pressure of the machine, please refer toWhat functional segments should be included in the internal resistance of the air conditioning box? . How to establish the fan pressure budget, please refer toHow is the total pressure of the air conditioning box fan determined by the internal resistance and external demand?。

Installation space and maintenance methods influence the choice

The plate filter has a small thickness and is suitable for units with limited space; bag filters require longer installation depth and extraction space. When replacing, the bag body of the bag filter needs to be carefully pulled out to avoid dust accumulation in the bag from being scattered. The location and replacement method of differential pressure monitoring points also vary depending on the structure.

When the horizontal air-conditioning box is arranged against the wall, which side should be left for inspection? Please refer toWhen a horizontal air-conditioning box is arranged against a wall, which side should be left for inspection? . The extraction direction and maintenance space of the filter should be confirmed during the box structure design. For the layout of the mixing section and filtering section, please refer toHow long is the air mixing distance required in the mixing section of the air conditioning box?。

Check system compatibility before replacing filter types

When changing from the plate type to the bag type, you should confirm whether the installation frame, compression structure and rear space are suitable; when changing from the bag type to the plate type, you need to recheck the effective filtration area and operating resistance. When replacing the filter, you should not only check whether the outer frame can be stuffed in, but also check whether the airflow bypass and fan operating points have changed.

For sealing and tightening of the filter installation frame, please refer toHow to configure the primary-efficiency and medium-efficiency filters of air-conditioning boxes in different stages? . After the internal resistance changes, the fan operating point may need to be rechecked. Please refer toWhy should we check the efficiency range when selecting air-conditioning box fans?。

Aili industrial supporting equipment

Aili Industrial can check the filter structure and the installation space in the box, and provide original filter material size, operating air volume and pressure difference records to help evaluate replacement options. Aili Industrial has air filter manufacturing capabilities and can jointly confirm the filter size, grade, head-on wind speed, initial resistance and installation method with the air-conditioning box structure; the manufacturing end covers independent research and development and production of motors and fans, control systems, sheet metal, air filters and complete machine assembly. The installation frames and box interfaces of plate and bag filters can be aligned in the same set.

Product form can be viewedAir handling unit andFan box page; terminal particle filtration can be combinedHEPA/ULPA filter confirmation; clean air supply package can be combinedFFU fan filter unit andCheck the fan filter unit at the EFU equipment end ; when it comes to gaseous pollution control, you can communicate separatelyChemical filter solutions. The specific structural form, filtering effect and delivery scope still need to be verified based on the corresponding configuration data and on-site working conditions. Actual results are subject to on-site leak detection and particle test results.

Submit project parameters:https://ailigy.com/contactus.html

Related questions and answers

Are bag filters necessarily more efficient than plate filters?
uncertain. Efficiency depends on the grade of filter material and evaluation standards. The structural form affects the effective area, resistance and dust holding capacity. Efficiency cannot be judged by appearance alone.

Can the plate filter be directly replaced by a bag filter?
It depends on the installation depth, compression structure and rear space. The bag body needs room to expand. You cannot just confirm the outer frame size.

Can Aili Industrial help compare plate type and bag type?
The applicability of the two structures can be checked based on the installation space, air volume and filtration requirements. The specific configuration needs to be confirmed based on product data and on-site working conditions.

Related articles

1. How to configure the primary-efficiency and medium-efficiency filters of air-conditioning boxes in different stages?

2. How to select the air conditioning box filter grade based on the inlet air conditions?

3. What needs to be considered when arranging the filter section before and after the fan?

4. What functional segments should be included in the internal resistance of the air conditioning box?

Key points for selection and acceptance inspection