GUANLIN primary efficiency pleated paper frame filter, G3 G4 pre-filter panel for HVAC and AHU ventilation systems.
G3 and G4 primary efficiency pleated panels with moisture-resistant paper frames, protecting coils and downstream filters from coarse dust and lint in HVAC and AHU systems.
Description
Every staged filtration system starts with a coarse stage that costs little and saves a lot. A primary efficiency panel removes the lint, fibres, insects and coarse grit that would otherwise load the medium stage within weeks, and it does so at the lowest cost per unit of air cleaned in the whole system.
Why Choose GUANLIN Primary Efficiency Panels
- Lowest cost per stage — the cheapest protection for everything behind it.
- G3 and G4 options — matched to the dust load and specification.
- Rigid paper frame — resists humidity and holds the pleat pack square.
- Low initial resistance — minimal fan energy penalty.
- Direct replacement — standard HVAC panel dimensions.
- Custom sizes — any dimension to your opening.

Application Scenarios
AHU first stage
Protects coils, fans and the medium stage from coarse loading.
HVAC systems in commercial buildings
Low-cost coarse protection that keeps fan energy stable.
Spray booths and paint lines
Captures overspray and lint before the more expensive stages.
Industrial ventilation and make-up air
General factory air cleaning at the lowest consumable cost.
Cleanroom pre-stage
First line of defence ahead of medium and HEPA filters.
Data centre air handling
Coarse dust control for coils and server inlets.

Our Factory

GUANLIN has manufactured filtration products in Dongguan since 2003, operating a 6,000 m² plant with automated filter bag sewing lines, automated singeing equipment, cage welding systems and pleated filter production lines. Products are exported to Singapore, Vietnam, Malaysia and other markets, with ISO 9001 and ISO 14001 certified quality management.
Product Specifications
| Item | Specification |
| Efficiency | G3 / G4 (EN 779) |
| Media | Synthetic fibre pleated media |
| Frame | Moisture resistant paper |
| Thickness | 21–46 mm |
| MOQ | 50 pcs |

FAQ
Q1. G3 or G4?
G4 for finer arrest; G3 where the coarse load is very heavy.
Q2. How often to change?
Typically 1–3 months; change at final pressure drop.
Q3. Custom sizes?
Yes, any dimension.
Q4. MOQ and lead time?
50 pcs, 10–20 days.
Key Specifications
- Efficiency: G3 / G4
- Frame: moisture resistant paper
- Sizes: standard and custom
- MOQ: 50 pcs





