Can ultra-thin EFU be equipped with a chemical filter layer?

The ultra-thin EFU itself is designed for space-constrained device-side applications. Its structure is compact, and the fan, filter and box are all pressed into a very thin height.

When gaseous pollution occurs inside the equipment and a chemical filter layer needs to be added to the air supply path, the question arises: Is there room for adding another layer to the already thin EFU?

The answer depends on several conditions: overall available height, effective filter area, fan static pressure margin, and maintenance methods. Just because the chemical filter layer itself is very thin, you cannot think that it can be added. For specific selection logic, please refer to Discussion on why EFU needs supporting chemical filters .

Take the overall space as the boundary

When evaluating the feasibility of retrofitting, all occupancies must be taken into account.

Total height limit. What is the maximum height allowed for an EFU to occupy inside the device? This value is fixed by the equipment structure and cannot be exceeded.

Existing EFU occupied. The ultra-thin EFU itself already uses most of the height. Fans, particle filters, box structures, and seals are all arranged in a limited space.

Added new chemical filter layer. After adding the chemical filter layer, is the total height still within the allowable range? Frame, sealing and mounting tolerances also need to be deducted. It’s not just about the thickness of the filter material itself.

Replace the path. After it is installed, can it be taken out for maintenance? There may be mechanical arms, cables, and structural parts inside the device. The ultra-thin EFU itself has limited disassembly space, and it may be more difficult to replace it after adding a filter layer. For specific measurement methods, please refer to Discussion of how to determine configuration when chemical filter thickness is limited .

Only by clearly listing the boundaries of these spaces can we judge whether the installation plan is feasible.

Check capacity and pressure loss

Space allows, but it also depends on the actual processing capacity of the chemical filter layer.

Low profile configurations have limited capacity. The thickness of the chemical filter layer is small, and less media can be installed. The limited capacity means the service life is likely to be shorter and replacement intervals may be much shorter than for particulate filters. Can the project tolerate more frequent replacements? For specific life assessment, please refer to Discussion of how long chemical filters last .

Passing wind speed should be checked. Thin filter layers have a smaller effective area. Under the target air volume, the passing wind speed may be high, the contact time between the gas and the medium is shortened, and the treatment effect may be reduced. When selecting, confirm the efficiency data of the target gas at the wind speed. For specific calculation methods, please refer to Discussion on how to calculate the removal efficiency of chemical filters .

Increased resistance affects the fan operating point. Installing a chemical filter layer will increase system resistance. The fan static pressure margin of ultra-thin EFU is usually not large. If the new resistance exceeds the fan capacity, the air volume may decrease, affecting the clean air supply inside the equipment. For specific accounting methods, please refer to Discussion of how much the added resistance of the chemical filter will increase the fan's electricity consumption .

You cannot judge the impact just by looking at the thickness of the filter material. Thin media can also cause significant drag, especially when passing wind speeds are high. Specific resistance data should come from product information or supplier confirmation.

Compare supporting locations

If there is really not enough space inside the ultra-thin EFU, other locations can be evaluated.

In front of the EFU air inlet. Set up an independent chemical filter section before the EFU air inlet. This method does not occupy the internal space of the EFU, but it is necessary to confirm whether there is a place to install it inside the equipment and whether the airflow passes through the filter section. For specific configuration, please refer to Discussion of what localized contamination can be treated by FFU plus chemical filter .

outside the device. If the equipment structure allows, a chemical filtration section can be set up outside the equipment, and the treated air can then be sent into the inside of the equipment. This method has less space restrictions, but needs to check the pipeline resistance and sealing.

Overall program adjustment. If the existing ultra-thin EFU cannot be equipped with a chemical filter layer, you may need to re-evaluate the EFU selection, choose a structure that reserves space for the chemical filter section, or adjust the internal layout of the equipment.

Target wind speeds must be verified for each scenario. After addition or adjustment, the wind speed and airflow coverage in key areas inside the equipment must not decrease. For specific measurement methods, please refer to Discussion on how to check the target wind speed after FFU is equipped with a chemical filter .

Post-installation verification

No matter which method is used, verify the actual performance after installation.

Air volume measurement. Measure the wind speed and air volume on the air outlet surface in the working position to confirm that it still meets the design requirements after installation. If the air volume drops significantly, you need to go back and check the fan operating point or filter resistance.

Outlet concentration detection. Detect the target gas outlet concentration according to project requirements to confirm the treatment effect. You can't judge the effect just by 'installed'.

Seal inspection. After installing the filter layer, the interface sealing must be re-confirmed. Frame bypass allows untreated air to bypass the filter material, affecting the outlet concentration. For specific inspection methods, please refer to Discussion on how to check frame bypass after chemical filter installation .

Maintenance path confirmation. Confirm that replacing the chemical filter layer is feasible. The internal space of the equipment is limited, and replacing the filter element may require disassembly of other parts. Maintenance access and operating spaces should be confirmed during the planning stage. involving The overall solution, interface and maintenance method of the fan filter unit at the EFU equipment end need to be checked together.

Project judgment example

The reserved EFU installation height inside a certain device is only 70 mm. The original EFU is an ultra-thin type with a particle filter already installed. After the equipment was operated, it was found that there was a trace amount of acidic gas inside, and chemical filtration needed to be added.

Preliminary assessment: A chemical filter layer is installed inside the EFU, but the usable height is insufficient, and the added resistance will cause the air volume to drop by about 20%.

Adjustment plan: Set up an independent thin chemical filter section in front of the EFU air inlet, and use a free space inside the equipment for installation. The filter section and the EFU are connected with a short tube to ensure that the airflow passes through the filter section. After installation, measure the wind speed and gas concentration inside the equipment to confirm that it meets the requirements. The replacement cycle of the chemical filter section is scheduled according to the operating data.

This case illustrates that adding a chemical filter layer to an ultra-thin EFU does not necessarily have to be solved inside the EFU, and other locations can be evaluated. involving For the configuration of the chemical filter product series , it is recommended that the equipment structure, space conditions and target gases be provided to the supplier for verification.

Key points for selection and acceptance inspection

About Aili Industrial’s ultra-thin EFU chemical filtration kit

When adding a chemical filter layer to ultra-thin EFU, the core is to check the overall space, effective area, fan static pressure and maintenance methods, and then select a matching configuration.

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. For equipment-side projects, the equipment structure, available height, target gas and air volume requirements can be combined to help check the configuration of the chemical filter layer. When the filter is matched with EFU, FFU and other equipment, the resistance, interface and maintenance methods can be confirmed uniformly.

Related products:Chemical filter product series、FFU matching chemical filter、MAU box chemical filter . When enquiring, provide the equipment structure, space conditions and target gas to help confirm the appropriate installation plan. The specific selection is subject to the technical documents and test results confirmed by the project.