Should the high-efficiency filter of the air-conditioning box be placed inside the machine or at the end of the air supply?

Whether the high-efficiency filter is placed in the air conditioning box or at the air supply end should be determined by the pollution control path, air duct risks and leak detection and maintenance conditions. Just because HEPA is installed in the machine does not automatically mean that the terminal can be eliminated; if HEPA is already installed at the terminal, it does not mean that upstream filtration and pipeline cleaning can be omitted.

Check the risk along the air path after the last stage of filtration

If there are long air ducts or other components after high-efficiency filtration in the machine, the rear section may become a new source of particles; the terminal filtration is closer to the service area, but requires installation space, sealing and on-site inspection conditions. For centralized in-machine filtration solutions, the cleaning and sealing of subsequent air ducts should be evaluated; for terminal solutions, the number of terminals, resistance and maintenance arrangements should be confirmed.

The internal layout of the machine should pay attention to whether the filtered air ducts and components are controlled; the terminal layout should pay attention to room interfaces, accessibility, and on-site inspection conditions; the combined layout should clearly define the protection objects at each level to avoid unnecessary repeated additions. Each of the three methods has applicable conditions and is not a simple ranking of advantages and disadvantages. For the grading relationship between high-efficiency filters and primary and intermediate efficiencies, please refer toHow to configure the primary-efficiency and medium-efficiency filters of air-conditioning boxes in different stages?。

Advantages and limitations of in-flight layout

The internal layout of the machine concentrates high-efficiency filtration in the air-conditioning box, which facilitates unified management and centralized leak detection. For multi-terminal systems, the number of terminal filters can be reduced. However, if the filtered air duct is long, contains dust, or is not tightly sealed, the end may still be contaminated. The filter section inside the machine also requires sufficient maintenance space and leak detection conditions, and the box structure must be able to withstand the resistance and compression requirements of the high-efficiency filter.

The resistance of the filter section in the machine will be included in the pressure budget of the whole machine, please refer toWhat functional segments should be included in the internal resistance of the air conditioning box? . The position of the filter section before and after the fan will also affect sealing and maintenance. Please refer toWhat needs to be considered when arranging the filter section before and after the fan?。

Advantages and limitations of end placement

The terminal arrangement puts the high-efficiency filter at the air supply outlet or at the end of the clean air supply, closer to the service area. The filtered path is short and the risk of air duct contamination is relatively small. However, when the number of terminals is large, the workload of leak detection, replacement and maintenance increases, and the sealing and installation quality of each terminal need to be confirmed individually. End filters also increase air supply resistance and take up space.

Common forms of terminal filtration include high-efficiency air supply vents and FFU packages, which can be combinedFFU fan filter unit andLearn about HEPA/ULPA filters . For partial protection on the equipment side, please also refer tothe fan filter unit at the EFU equipment end .Configuration method of

The responsibilities of each level should be clearly stated in the combination arrangement

When high-efficiency filters are installed both inside the machine and at the end, it is necessary to explain what tasks each stage undertakes. The in-machine stage may be used to protect the rear air duct or as the main filtration, and the terminal stage is used to protect the nearby service area. When both levels are installed, the resistance, leakage detection and maintenance arrangements should be checked separately to avoid the situation where they are all installed but the responsibilities are unclear.

The combined layout will also affect the fan pressure budget and terminal air volume distribution. Please refer toHow is the total pressure of the air conditioning box fan determined by the internal resistance and external demand? andIs the air supply volume of the air conditioning box determined based on the number of air changes or the cooling and heating load?。

The final plan should specify the verification objects

It should be stated whether it is the filter material, the installed filter unit, or the overall performance of the room that needs to be verified. These three cannot replace each other. For items that must be checked for integrity in use, the inspection port and operating space should be arranged at the design stage, and testing cannot be considered after the equipment is installed.

Leak detection methods and acceptance conditions should also be agreed in advance. The leak detection port of the filter section in the machine, the scanning space of the end filter and the upstream dust generation conditions all need to be reserved during the structural design. If the project has clear requirements for cleanliness, it should also be combined with room airflow organization and pollution source management, and cannot just rely on the filter itself.

Aili industrial supporting equipment

Aili Industrial can jointly check the interfaces around the air conditioning box, HEPA filter and high-efficiency air supply outlet, but the final layout should be consistent with the project's pollution control and verification plan. Aili Industrial has air filter manufacturing capabilities and can jointly confirm the filter size, efficiency level, installation method and leak detection conditions with the 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 filter sections and end interfaces in the machine can be aligned in the same set of packages.

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 filtration effect, leak detection conditions 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

There is a high-efficiency filter installed in the machine, is it still needed at the end?
It is not necessarily necessary, but it depends on the cleanliness and sealing status of the air duct after filtration, as well as the cleanliness requirements of the service area. You cannot default to canceling the end after filtration in the machine.

Are the more high-efficiency filters at the end the better?
no. Increased number of ends creates leak detection, replacement, and resistance issues that should be determined based on service area and validation protocol.

Can Aili Industrial help determine the location of high-efficiency filtration?
The in-machine or terminal plan can be checked based on the pollution control path, air duct conditions and leak detection and maintenance requirements. The specific layout needs to be confirmed according to the project verification plan.

Related articles

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

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

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

4. How is the total pressure of the air conditioning box fan determined by the internal resistance and external demand?

Key points for selection and acceptance inspection