Can chemical filters and ULPA filters be substituted for each other?

At some project sites, chemical filters and ULPA have similar dimensions and can even fit into the same frame. Some people may think: Since they can all be installed, can they be substituted for each other?

The answer is no. The two filters process different objects, have different evaluation criteria, and perform different tasks in the system. Similar appearance is just a coincidence and cannot be used as a basis for substitution. For specific division of labor, please refer to An explanation of the difference between chemical filters and HEPA filters .

High particle grade does not equal molecular control capabilities

This is the most confusing point.

ULPA's grades—U15, U16, U17—describe the filtration efficiency for particles of a specific particle size. No matter how high this value is, it only shows the particle control ability, not the treatment effect on gaseous pollutants.

Chemical filters deal with gas molecules and evaluate the removal efficiency, adsorption capacity and penetration time of target gases. A ULPA system can control particles very well, but has little ability to remove acid gases, ammonia or organic vapors.

The reverse is also true. Gas treatment data for a chemical filter does not prove that it achieves a certain particle filtration level. The two evaluation systems do not overlap and cannot be converted to each other.

involving The selection of ULPA ultra-high efficiency filter can be checked with specific product information.

Replacement will change system functionality

What would happen if the ULPA in the system was replaced with a chemical filter, or vice versa?

Remove the ULPA layer : particle control capabilities may be reduced. If the process has requirements for particles, this change may directly affect product yield.

Remove the chemical filter layer : the gaseous pollution treatment capability disappears. If the project has AMC control requirements, the gas concentration may increase.

Adding a new layer of filter : the total resistance of the system increases, the fan working point shifts, and the air volume may decrease. Even if the new filter functions fine, there may be problems with system matching.

So replacement is not just about replacing a part, but changing the function of the system. Before deciding to replace, you must first confirm whether this function is required by the project and whether the system can withstand changes.

Sensitive processes may require both

In many practical projects, particle control and gas control coexist.

Semiconductor manufacturing : Photolithography, etching and other processes require both particle control and specific gas composition control. Two needs exist at the same time, and only one of them cannot be satisfied.

Precision electronics and sensor packaging : The surface of the product is not only afraid of particles, but also afraid of the deposition of certain volatile matter. The air supply system may need to be equipped with both ULPA and chemical filtration sections.

Pharmaceuticals and Biomedicine : Sterile areas must control particles and may also need to deal with external odors or specific gases. For specific configuration methods, please refer to Description of MAU Box Chemical Filter .

In this type of project, the two filters are in a cooperative relationship, not a substitution relationship. They each undertake their own tasks and jointly ensure the process environment. Supporting For FFU systems equipped with chemical filters , the sequence of filter sections, resistance and maintenance methods also need to be checked.

Avoid mixing performance when matching

In the combined system, external information can indicate that it has both particle and gas control capabilities, but attention should be paid to distinguishing the responsibilities of each layer.

One level cannot describe two functions. ULPA ratings cannot be used to describe gas handling capabilities; chemical filter efficiency data cannot describe particle control levels.

Detection methods should be separated. Particle detection and gas detection use different instruments, sampling methods and judgment standards. During acceptance, they should be confirmed and recorded separately.

The basis for maintenance is also different. The replacement of ULPA depends on the pressure difference and leak detection results; the replacement of chemical filters depends on the gas processing capacity consumption. The maintenance cycles and judgment methods of the two are different, and the ledgers must be managed separately.

It is much easier to calculate the interface, sequence and resistance of the two-layer filter clearly at the system design stage than to make adjustments during operation. For specific configuration, please refer to the Chemical Filters product range . Product description for

Project judgment example

A certain wafer handling equipment needs to control the internal environment.

The preliminary plan only installed ULPA, thinking that high-level filtration can solve all problems. After running for a period of time, the particle indicators are normal, but there are unexplained metal surface changes inside the equipment.

The investigation found that there was a trace amount of acidic gas in the environment, and the source was related to emissions from nearby processes. ULPA does not have the ability to handle this type of gas, so the problem cannot be solved.

Adjustment plan: Add a chemical filtration section suitable for acid gases on the air supply path, while retaining ULPA for particle control. After the resistance, interfaces and maintenance methods of the two-stage filters were rechecked, the system returned to normal operation.

This case illustrates: ULPA and chemical filters have their own functions and cannot replace each other. involving HEPA/ULPA air filters has the same judgment logic. The combined configuration of

Key points for selection and acceptance inspection

About Aili Industrial's combination configuration package

The core of the combination of particle filtration and gas phase filtration is to separately confirm the two types of requirements and then check them uniformly at the system level.

Aili Industrial has independent manufacturing capabilities in filters, motors, fans, control systems and sheet metal processing, and can provide ULPA/HEPA filter and chemical filter product series. For projects involving both particle and gas control, the sequence, resistance, and interfaces of the two-stage filters can be checked together during the planning stage to reduce rework caused by configuration mismatch after installation.

Related products:Chemical filter product series、ULPA ultra high efficiency filter、FFU comes with chemical filter . A separate list of particle control targets and gas targets is provided during the inquiry to help confirm the appropriate combination solution. The specific configuration is subject to the technical documents and test results confirmed by the project.