Non-woven filters and woven filters are the two mainstream types of high-efficiency air filters (HEPA), differing significantly in structure (with or without separators), performance, and applicable scenarios. The following is a comparative analysis of both advantages and disadvantages:
I. Advantages and Disadvantages of Non-woven Filters
Advantages
Compact in size and space-saving
The filter without separators fixes the filter material through hot melt adhesive or a folding process, without the need for metal or paper separators. Under the same filtration area, its thickness is only 1/3 to 1/2 of that of the filter with separators (for example, the thickness of a conventional filter without separators is about 22-90mm, while that of a filter with separators is 150-300mm). Suitable for scenarios with limited space (such as cleanroom ceilings, small biosafety cabinets).
Light in weight and easy to install
The filter material and frame material are lighter (such as aluminum frame, plastic frame), and the weight of a single unit is usually more than 50% lighter than that of the filter with separators of the same specification, reducing the load-bearing requirements during installation and labor costs.
Lower wind resistance and better energy consumption
The filter material folds more evenly, the air flow channel is smooth, and the initial air resistance is usually 150-250Pa (about 250-350Pa with partitions). Under the same air volume, the load on the fan can be reduced, making long-term operation more energy-efficient.
The stability of the filtration efficiency is higher
The design without separators avoids the “bypass flow” phenomenon that may occur at the edge of the separators (particles leaking from the gaps of the separators), and the hot melt adhesive seal is tighter. The stability of the filtration efficiency (especially for H13-H14 grades) is better than that of the filter with separators.
Suitable for high-cleanliness scenarios
It can easily achieve U15-U17 grade (ultra-high efficiency, ULPA) filtration efficiency, meeting the requirements of ISO Class 3 and below clean rooms (such as semiconductor chip manufacturing, satellite assembly), while the pleated filter is restricted by its structure and is difficult to reach the ultra-high efficiency grade.
Disadvantage
The cost is relatively high.
The filter material folding process is more complex (high-precision equipment is required to ensure uniformity), and the cost of hot melt adhesive materials is higher than that of ordinary separators. Therefore, the unit price is usually 30%-50% higher than that of filters with separators of the same specification.
It has poor heat resistance.
The temperature resistance of hot melt adhesives generally does not exceed 80℃ (some special adhesives can reach 120℃), while the metal separators of the filter with separators can withstand temperatures above 150℃. Therefore, their applicability in high-temperature environments (such as oven exhaust purification) is limited.
It has a relatively weak impact resistance.
The filter material is only fixed by the rubber thread. If the airflow suddenly fluctuates violently (such as when the fan starts or stops), it may cause the filter material to deform or the rubber thread to detach. However, the rigid partition of the filter with a separator provides more stable support for the filter material.
Ii. Advantages and Disadvantages of Pleated Filters
Advantages
Low cost
The filter material is separated by metal (aluminum foil) or paper partitions. The process is simple, and the material cost is low. It is suitable for scenarios that are sensitive to the budget and do not have extreme cleanliness requirements (such as ordinary pharmaceutical workshops and food packaging workshops).
Strong heat resistance and stability
The metal partition can withstand high temperatures (150-300℃) and high-humidity environments. Moreover, the filter material is fixed by the partition, which has strong resistance to air flow impact and is suitable for the ventilation systems of ovens and high-temperature sterilization equipment.
Good maintenance compatibility
The structure is relatively simple. The installation dimensions of some old purification systems are specially designed for filters with separators. When replacing, there is no need to modify the equipment, and the compatibility is higher.
Disadvantage
It has a large volume and a high space occupation rate
The thickness of the separator (usually 5-10mm) results in a large overall size. Under the same filtration area, the installation space requirement is 2-3 times that of a filter without separators, making it unsuitable for compact Spaces.
High wind resistance and high energy consumption
The partition will block some of the airflow, and the folding density of the filter material is low, resulting in a relatively high initial air resistance (250-350Pa). Long-term operation will increase the energy consumption of air conditioners or fans.
The upper limit of filtration efficiency is low.
Gaps may form at the edges of the partition, causing particle leakage and making it difficult to achieve ultra-efficient filtration above the U15 level. The highest is usually the H13 level, which cannot meet the demands of high-end scenarios such as semiconductors and precision optics.
Iii. Core Differences Comparison Table
Compared with the non-partitioned filter, there is a partitioned filter
Structural hot melt adhesive/folding fixation, no metal/paper separator to separate the filter material
Thickness: 22-90mm, 150-300mm
The filtration efficiency is H13-H14 grade, which can reach U15-U17 grade, mostly H10-H13 grade, and it is difficult to exceed H14 grade.
Initial wind resistance: 150-250Pa, 250-350Pa
Temperature resistance: ≤80℃ (Special adhesive: ≤120℃); ≥150℃ (metal partition)
The cost is relatively high (30%-50% more expensive) and relatively low
It applies to scenarios with high cleanliness, compact Spaces (such as semiconductors and operating rooms), medium to low cleanliness, high temperatures, and limited budgets
Summary
Non-woven filter: Suitable for scenarios with high requirements for space, energy consumption, and high cleanliness (such as chip manufacturing, ICU, precision instruments), but it is relatively expensive and has limited temperature resistance.
Pleated filters: Suitable for systems with limited budgets, high-temperature environments, or old systems, but they are large and have a low upper limit of efficiency.
When making a choice, a comprehensive judgment should be made by taking into account the cleanliness level, space dimensions, ambient temperature, and cost budget.