

The Thesvin Separator Box Filter is a rigid box-style pleated filter with corrugated separators, designed for medium-efficiency pre-filtration in commercial air handling units, cleanroom systems, and industrial ventilation. It captures particles from outdoor and recirculated air to protect downstream high-efficiency filters and equipment. Available in G4 through F9 efficiency grades, it suits HVAC engineers, facility managers, and OEMs who need reliable fitment and consistent dimensional accuracy.
Fitment is where this filter proves its value. The box frame—available in aluminum or galvanized steel—provides a rigid structure that resists deformation under high airflow, while the corrugated separators maintain even pleat spacing and prevent media rupture. Standard depths of 15 and 21 inches (381 mm and 534 mm) match common AHU filter racks and side-access housings, and the square and rectangular face sizes align with nominal 24×24, 24×20, and 12×24 inch openings.
The filter locates positively in the holding frame; its rigid construction minimizes bypass and ensures a flush seal against the frame gasket (gasket not included unless specified). For retrofit or non-standard racks, Thesvin supports custom sizes and frame configurations to match your existing drawing or old part. The result is a drop-in replacement that maintains airflow and filtration performance without modification to the host unit.
This filter targets particulate matter in ventilation and process air. The pleated media—either high-quality non-woven fiber or high-precision glass fiber—captures particles across a range of sizes, with efficiency grades from G4 to F9. It is commonly used as a pre-filter ahead of HEPA or ULPA stages in pharmaceutical cleanrooms, electronics manufacturing, hospitals, food processing, automotive paint shops, data centers, and energy facilities.
By removing coarse and medium-sized particles, the Thesvin Separator Box Filter extends the service life of terminal filters and protects coils, fans, and ductwork from fouling. The deep pleat design provides a large filtration area, resulting in high dust-holding capacity and low pressure drop over its service life.
| Item | Detail |
|---|---|
| Product name | Separator Pleated Rigid Box Filter |
| Efficiency grade | G4 / M5 / M6 / F7 / F8 / F9 |
| Media | High-quality non-woven fiber or high-precision glass fiber |
| Frame and support | Aluminum or galvanized steel frame with corrugated separators |
| Rated operating air velocity | 2.5 m/s (suitable for high-airflow ventilation systems) |
| Core applications | Pre-filtration for Class 100 cleanrooms in pharmaceutical and electronics plants; intake section of commercial AHUs; dust removal in paint shops; high-velocity industrial exhaust |
| Standard sizes (W × H × D) | 24×24×21 in (594 × 594 × 534 mm); 24×20×21 in (594 × 492 × 534 mm); 24×24×15 in (594 × 594 × 381 mm); 12×24×21 in (289 × 594 × 534 mm) |
| Customisation (OEM/ODM) | Custom sizes and non-standard frames supported; 50,000 m² factory with CNAS testing laboratory; ISO 9001/14001/45001 and IATF 16949 certified |
Thesvin operates a 50,000 m² manufacturing facility in Zhongshan, Guangdong, China, including six cleanrooms totaling 20,000 m². Our quality management system is certified to ISO 9001, ISO 14001, and ISO 45001, and in 2024 we obtained IATF 16949 certification for automotive quality. IQC, IPQC, and OQC controls run throughout production to ensure dimensional consistency and filter integrity.
Our CNAS-accredited laboratory can issue test reports for efficiency, dust-holding capacity, and pressure drop. With over 20 years of experience and more than 1,000 filtration solutions developed, we support OEM and ODM projects with custom sizes, frame materials, media grades, logos, and packaging. Multiple automated production lines enable monthly capacity of several million pieces.
To get an accurate quote and ensure perfect fitment, please provide your device or vehicle model, a size drawing or an old part, the required airflow or water flow, operating conditions, and quantity. Our engineering team will respond promptly. Contact us here to start your inquiry.
The Thesvin Separator Box Filter is available in standard sizes such as 24×24×21 inches (594×594×534 mm) and 24×20×21 inches (594×492×534 mm), which match common AHU filter racks. For non-standard racks, we support custom sizes and frame configurations. Send us your unit model or a drawing, and we will confirm fitment.
Yes, you can send an old part for reference. Our engineering team will measure it and propose a matching filter, including frame type and media grade. This is often the fastest way to ensure drop-in replacement.
The filter is available in G4, M5, M6, F7, F8, and F9 grades, covering medium-efficiency requirements. The appropriate grade depends on your application and downstream filter protection needs. We can advise based on your operating conditions.
For standard sizes, the MOQ is typically 50–100 pieces. Custom sizes are subject to confirmation based on dimensions and materials. We can accommodate flexible quantities for project orders.
Standard sizes ship within 15–20 days. Custom sizes typically require 25–35 days. For large orders, we will provide a precise delivery schedule based on production capacity.
Replacement interval depends on air quality and operating hours. Under typical commercial HVAC conditions, the filter lasts 12–18 months, but actual life varies with dust loading. We recommend monitoring pressure drop and replacing when it reaches the final resistance specified for your system.
Yes, samples are available. Standard sizes can be provided quickly, and custom samples typically take 7–15 days. Each sample includes test data from our CNAS-accredited laboratory, covering efficiency, initial pressure drop, and dust-holding capacity.
To receive a quote, please provide your device or system model, a size drawing or old part, the required airflow, operating conditions, and quantity. <a href="/en/contact">Contact us here</a> and our team will respond promptly.