Andreae AF423 High-Efficiency (HE) Cardboard Exhaust Filter – 20″ x 25″
The Andreae AF423 represents the pinnacle of accordion-style filtration technology. By combining the legendary loading capacity of the original Andreae pleated design with a specialized polyester backing layer, the AF423 delivers near-total filtration efficiency without the rapid pressure drops seen in traditional fiberglass pads.
This filter is specifically engineered for shops using high-solids, clear coats, and waterborne paints that require a cleaner exhaust stream and longer service intervals.
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Efficiency: Up to 99.8% (depending on the coating used).
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Design: Dual-layer “Kraft” paper + High-Loft Polyester media.
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Quantity: Industrial Bulk Pack (Box of 24).
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Ships within 24–48 hours.
Why the AF423 Outperforms Standard Filters
1. Hybrid Filtration Technology
Most filters rely on either Inertia (cardboard) or Mechanical Straining (polyester/fiberglass). The AF423 uses both. The accordion shape forces the air to change direction abruptly, flinging heavy paint particles into the “holding pockets.” The final polyester layer then catches the microscopic “fines” that would otherwise escape into your exhaust stack.2
2. High Loading Capacity (Life Span)
Standard flat filters “face-load,” meaning they clog on the surface and die quickly. The AF423 is a “depth-loading” filter. It can hold up to 5 times more overspray than standard fiberglass pads, keeping your booth’s airflow stable for significantly longer.3
3. EPA 6H & NESHAP Compliance
For shops under strict environmental oversight, the AF423 is a top-tier choice. Its high arrestance efficiency helps facilities meet and exceed federal mandates for hazardous air pollutant (HAP) emissions.
Specifications
| Feature |
Details |
| Model |
Andreae High Efficiency (HE) AF423 |
| Dimensions |
20″ x 25″ (Standard Frame Size) |
| Media |
Multi-layered Kraft paper with Polyester backing |
| Arrestance Efficiency |
Up to 99.8% |
| Loading Capacity |
4 – 11 lbs (Depending on coating density) |
| Packaging |
Box of 24 Filters |
Expert Insights: Maximizing Efficiency in 2025
The Secret to Airflow Balance
Many painters notice that as filters fill up, the booth pressure shifts. The AF423 is specifically designed to maintain a low initial pressure drop. Even as it accumulates paint, the pleated design allows air to bypass the heavy deposits through the sides of the pockets, maintaining a consistent CFM (Cubic Feet per Minute) for a longer duration than flat media.
Installation Best Practices
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Orient the “V”: Ensure the pleats are expanded correctly within the frame. Over-compressing the filter reduces the “pockets” where paint is stored.
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The Polyester Side: Always install the filter with the white polyester layer facing the exhaust fan (the air exit). The brown kraft paper should face the painter.
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Monitor Your Manometer: While these filters hold a massive amount of paint, do not wait for the fan to struggle. Change the filter once you reach the manufacturer’s recommended differential pressure (typically 0.5″ to 0.6″ w.g.) to protect your fan motor.
Looking for a different size? Additional sizes can be found at the links below:
