MAU chemical filters cannot directly replace medium-efficiency filters just because they are the same size. The main tasks of the two are different. Canceling the original particle pre-filtration may increase the load of subsequent filter sections. The overall configuration and actual filtration function should be evaluated. Before replacement, the tasks undertaken by the original filter section must be clearly dismantled.

The original mid-efficiency section is not just for 'blocking dust'

Medium-efficiency filters usually play the dual roles of particle prefiltration and downstream protection in MAU. It blocks larger particles in front, reducing dust accumulation on the surface cooler fins and contamination of the drain pan, and also reduces the dust holding pressure of the high-efficiency filter at the end. If a chemical filter element is used to occupy this position, there will be a gap in particle protection, and the frequency of cleaning and replacement costs of subsequent components may increase. Just because a chemical filter element is effective for target gases does not mean that it has the particle efficiency or dust holding capacity of the original medium-efficiency section. Regarding the division of labor between particle and gas filtration, please refer toThere is a high-efficiency filter in the clean room, why is there still smell?。

The acceptance objects of the two types of filter sections are different.

Medium-efficiency filters look at particle classification efficiency, initial resistance and dust holding capacity, while chemical filters look at target gas efficiency, capacity and penetration conditions. The testing methods, criteria and data calibers of the two are different. If the chemical filter element is used to replace the medium-efficiency filter, even if the size matches, it cannot be accepted by the original particle efficiency index, and the gas effect does not have the corresponding pre-particle protection to match. During the project acceptance, there will be a gap that 'no one is responsible for the particle index and the gas index lacks preconditions'.

Resistance and fan margin need to be recalculated

The initial resistance of the intermediate-efficiency section is usually lower than that of the chemical filter section, and direct replacement will change the resistance distribution of the entire machine. MAU fan selection is generally determined based on the superimposed resistance of each functional section. After the medium-efficiency section is replaced by the chemical section, both the initial resistance and the final resistance may increase. For a constant air volume system, the air supply volume will decrease; for a variable frequency system, the fan speed and power consumption will increase. The replacement evaluation should obtain the resistance data of the chemical filter section under actual air volume and compare it with the crude oil resistance, fan curve and margin. If the MAU is close to the upper limit of the fan's capacity, simply increasing the speed compensation may cause noise and control range problems. For accounting ideas on related resistance and operating costs, please refer toHow to check the residual pressure outside the machine after MAU adds a chemical filtration section?。

A more reasonable approach is to coexist in segments

In most MAU scenarios, the chemical filtration section and the original mid-effect section should coexist rather than replace each other. Common arrangements are to retain the granular pre-filtration and add a chemical filtration section afterwards, or to use a combined chemical and granular structure when space is limited. In this way, particle protection and gas treatment each have corresponding acceptance objects, and the fan margin is also rechecked based on the total resistance after superposition. If the air-conditioning box does have only one filter tank, you need to first confirm whether the particle task of the original mid-efficiency section can be taken over by other locations, and then determine whether the chemical section can be put in. For modifications involving air-conditioning boxes without reserved sections, please refer toCan I still install a chemical filter if the air conditioning box does not have a reserved filter section?。

Aili industrial supporting equipment

In projects such as MAU, we generally do not recommend that customers directly use chemical filters to move to the middle-efficiency position. Instead, we first look at the tasks of the original filter section, fan margin, and box space. If space allows, it is safer to retain the particle pre-filtration and add a chemical section after it; when space is tight, you can compare the combined structure or external filter box solution. Aili Industry can provide selection packages for box-type, flat-plate and V-type chemical filtration products. For box-type MAU packages, please refer toMAU box chemical filter page, product series can be viewedChemical filter product range . The manufacturing end covers motors, fans, control systems, sheet metal and complete machine assembly. Filter section resistance changes and fan operating points can be checked in the same package; if the original system involves replacing imported filter elements, adaptation can also be made according to interface and media requirements. The specific gas effect, resistance performance and replacement cycle still need to be verified based on the corresponding configuration data and on-site working conditions. The actual results are subject to on-site leak detection and gas detection results.

Related questions and answers

Can the medium-efficiency filter be replaced with a chemical filter if the size is the same?
Not recommended. Size is only one of the installation conditions, particle protection tasks, resistance changes and acceptance objects all need to be rechecked. Direct replacement may cause subsequent parts to lose pre-filter protection.

In MAU, should the chemistry section be placed before or after the medium effect?
Most scenarios are placed after particle pre-filtration, allowing the chemical section to process the air that has removed large particles to reduce media surface contamination. The specific sequence should be confirmed based on the box structure and airflow organization.

Can Aili Industrial help check the MAU filter section modification plan?
The tasks of the original filter section, fan margin and box space can be combined to compare the options of retaining pre-filtration, adding a new chemical section or a combined structure. The specific configuration needs to be confirmed based on the corresponding product information and on-site conditions.

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Key points for selection and acceptance inspection