Pleated Pre-Filter (Paper / Metal Frame)
Product Overview
Key Specifications
- Filtration Efficiency
- Dust-spot 30–35% (often called 35%); 45% (G4) version available
- Frame
- Cardboard, galvanized steel, aluminum or stainless steel frame
- Filter Media
- Synthetic-fiber non-woven media
Specifications
- Filter Media
- Synthetic-fiber non-woven media
- Frame
- Cardboard, galvanized steel, aluminum or stainless steel frame
- Separator
- Expanded metal mesh on both faces (eco version: white fleece, no metal mesh)
- Filtration Efficiency
- Dust-spot 30–35% (often called 35%); 45% (G4) version available
Model Reference
| Model | Description | Size |
|---|---|---|
| PP-12-24-1 | Primary paper frame filter 35% 12X24X1" | 12 × 24 × 1″ |
| PP-16-20-1 | Primary paper frame filter 35% 16X20X1" | 16 × 20 × 1″ |
| PP-495-395-22 | Primary paper frame filter 35% 495X395X22 | 495 × 395 × 22 mm |
| PP-16-25-1 | Primary paper frame filter 35% 16X25X1" | 16 × 25 × 1″ |
| PP-20-20-1 | Primary paper frame filter 35% 20X20X1" | 20 × 20 × 1″ |
| PP-20-24-1 | Primary paper frame filter 35% 20X24X1" | 20 × 24 × 1″ |
| PP-24-24-1 | Primary paper frame filter 35% 24X24X1" | 24 × 24 × 1″ |
| PP-12-24-2 | Primary paper frame filter 35% 12X24X2" | 12 × 24 × 2″ |
| PP-595-290-45 | Paper frame primary filter 595*290*45mm | 595 × 290 × 45 mm |
| PP-16-20-2 | Primary paper frame filter 35% 16X20X2" | 16 × 20 × 2″ |
| PP-16-25-2 | Primary paper frame filter 35% 16X25X2" | 16 × 25 × 2″ |
| PP-20-20-2 | Primary paper frame filter 35% 20X20X2" | 20 × 20 × 2″ |
| PP-20-24-2 | Primary paper frame filter 35% 20X24X2" | 20 × 24 × 2″ |
| PP-20-25-2 | Primary paper frame filter 35% 20X25X2" | 20 × 25 × 2″ |
| PP-24-24-2 | Primary paper frame filter 35% 24X24X2" | 24 × 24 × 2″ |
| PP-595-595-45 | Primary paper frame filter 35% 595X595X45mm | 595 × 595 × 45 mm |
| PP-12-24-4 | Primary paper frame filter 35% 12X24X4" | 12 × 24 × 4″ |
| PP-16-20-4 | Primary paper frame filter 35% 16X20X4" | 16 × 20 × 4″ |
| PP-16-25-4 | Primary paper frame filter 35% 16X25X4" | 16 × 25 × 4″ |
| PP-20-20-4 | Primary paper frame filter 35% 20X20X4" | 20 × 20 × 4″ |
| PP-20-24-4 | Primary paper frame filter 35% 20X24X4" | 20 × 24 × 4″ |
| PP-20-25-4 | Primary paper frame filter 35% 20X25X4" | 20 × 25 × 4″ |
| PP-24-24-4 | Primary paper frame filter 35% 24X24X4" | 24 × 24 × 4″ |
Common sizes are listed above. Other sizes, frame materials and efficiency grades can be made to order — please quote the model or size when requesting a quotation.
Detailed Description
Paper or metal frame?
346 pleated pre-filter models: frame × thickness
Number of models we have made (from our model list)
1″ means about 15–30 mm, 2″ about 40–56 mm and 4″ about 90–102 mm; "Other" covers thicknesses outside these ranges.
How to choose between 1″, 2″ and 4″
Check how deep the filter slot in the air handling unit is, and when replacing, order the same thickness as the old filter. 1″ (about 20–25 mm) is the most common, then 2″, with 4″ less common. A thicker filter has deeper pleats and more media, so it holds more dust.Are 35%, 30–35%, G4 and 45% the same thing?
Customers often write "PRE 30–35%" or "35% pre-filter" — both mean the main version on this page. 45% (G4) is a version one step higher in efficiency and less common; for 65% and above, see the medium-efficiency pleated filter. G4 is an old European EN 779 class (average arrestance of 90% or more), and EN 779 was replaced by ISO 16890 in 2018.Often replaced together with bag filters
During air handling unit maintenance, pre-filters are often replaced in one batch together with the bag filters behind them — for example 1140 pre-filters of 593×593×22 mm at once, along with the bag filters for the same units. We can replace them on site as part of a maintenance job and take away the used filters.Specifications
- Frame: paper, galvanized steel, aluminum or stainless steel - Thickness: 1″ (about 20–25 mm), 2″ (about 45–50 mm), 4″ (about 95–100 mm) - Efficiency: 30–35% dust-spot, with a 45% (G4) version - Rated airflow and pressure drop: provided per selectionFrequently Asked Questions
How do I choose between 1″, 2″ and 4″?
Measure how deep the filter slot in the air handling unit is, and order the same thickness as the old filter. 1″ (about 20–25 mm) is the most common — 172 of our 346 pleated pre-filter models; 2″ accounts for 129 and 4″ for 26. A thicker filter has deeper pleats and more media and holds more dust, as long as the slot can take it.
What is the difference between paper and galvanized frames?
Paper frames are mostly inch standard sizes such as 12×24 and 24×24 and are discarded whole after use; non-standard paper frames need a die when ordered in volume. Galvanized frames are metal and mostly made to fit equipment in metric non-standard sizes, such as 530×530×45 mm. Among our models, 184 are galvanized and 111 are paper.
An inquiry says "35%", "30–35%", "G4" or "45%". Are these the same?
"35%" and "30–35%" are the same — the main version at 30–35% dust-spot. "45%" or "G4" is a version one step higher in efficiency with fewer models; G4 is an old class from the European EN 779 standard, which was replaced by ISO 16890 in 2018. If unsure, send us a photo of the label on the old filter.
My size is not standard. Can you make it?
Yes. Galvanized frames are mostly made to fit equipment anyway — we have made 530×530×45 and 248×455×45 mm, for example. Paper frames can also be made in non-standard sizes, but a die is needed for volume orders, so for small quantities a galvanized frame is usually the better choice. Please give width × height × thickness (mm), efficiency and quantity.
Selection References
Before ordering, verify the efficiency grade, media type, and whether the operating environment fits your requirements.
