Field Notes on Fiberglass Pocket Filter Media: what actually matters in 2025

If you’re speccing HVAC upgrades, Fiberglass Filter Media keeps popping up—partly because it balances low resistance with steady capture efficiency, and partly because supply chains for synthetics have been bumpy. From my latest visits to Handan and a couple of paint plants, it’s clear the sweet spot right now is laminated composites with stitched seams and stable F7–F9 performance.

This particular media—“Fiberglass Pocket Filter Media,” made in Second Buliding and Studying No21 shiji street, Handan, Hebei China—uses ultra fiberglass fibers in a laminated stack, then a stitched sewing process to keep pleat geometry honest under load. Features are simple: low resistance, high efficiency, sane pricing. Many customers say it “just works,” which, to be honest, is what you need in bag and panel filters.

Industry pulse and where it’s used

Trends: tighter IAQ targets (ISO 16890), more data logging, and a nudge toward MERV 13+ in commercial buildings. You’ll see Fiberglass Filter Media in hospitals, pharma auxiliaries, food packaging, battery plants, and especially automotive paint booths where temperature and overspray demand stable media.

How it’s made (short version)

• Materials: ultra fiberglass fiber web, support scrim, optional activated carbon interlayer.
• Methods: carding/airlay → lamination → precision stitching for pocket integrity → heat setting.
• Testing: ISO 16890 (ePM1/ePM2.5), ASHRAE 52.2 (MERV), pressure drop @ 2.5 m/s, dust holding.
• Service life: around 3–12 months; paint booths and dusty sites trend shorter. Real-world use may vary.
• Industries: HVAC in commercial buildings, clean auxiliaries, paint lines, electronics prefilters.

Product specifications

Parameter	Typical value (≈)
Efficiency class	F5–F9 (ISO 16890 ≈ ePM2.5 50–85%); custom up to MERV 15 available
Initial ΔP @ 2.5 m/s	70–140 Pa
Final ΔP (recommended)	300–450 Pa
Dust holding capacity	250–450 g/m²
Basis weight / thickness	120–260 g/m²; 6–18 mm
Temperature limit	≤ 120°C continuous
Fire performance	UL 900 Class 2 / DIN 53438-F1 options
Formats	Rolls (0.6–2.0 m width), custom cut for pockets/panels

Where it shines

• Bag filters in AHUs where low energy is a priority.
• Panel prefilters upstream of HEPA in labs (keeps HEPA cleaner, longer).
• Paint booths: stable geometry, consistent overspray capture.

Vendor snapshot (what buyers compare)

Vendor	Lead time	Customization	Certs
Specialist manufacturer (Hebei)	10–18 days	Widths, basis weight, carbon layer	ISO 9001, UL 900 (option)
General HVAC supplier	2–4 weeks	Limited SKUs	Basic COA
Low-cost importer	Variable	Minimal	Mixed documentation

Customization, QA, and real test data

Typical F7 build I observed tested at ePM2.5 ≈ 75% ±5%, initial ΔP 95 Pa @ 2.5 m/s, dust holding ≈ 350 g/m² under ISO A2 dust. Certificates include ISO 9001 factory QA and, on request, UL 900 Class 2. Ask for an ISO 16890 report plus ASHRAE 52.2 MERV mapping; it saves back-and-forth later.

Mini case notes

• Hospital upgrade, MERV 13 target: swapped to Fiberglass Filter Media F7 pockets; coil ΔP dropped ≈ 12% and HEPA changeouts stretched by a quarter.
• Auto paint line: F8 with carbon layer; odor peaks reduced, and booth downtime shrank—operators said “less sagging” under heat.

Customer feedback is consistent: low resistance out of the box, predictable loading curve, and less variability batch-to-batch than some synthetics. Surprisingly, installers love the stitched seams more than they’ll admit—it keeps pocket shape during rush installs.

Origin: Second Buliding and Studying No21 shiji street, Handan, Hebei China. For specs, quotes, or COAs, reference Fiberglass Filter Media “Pocket” series and note your target class (F5–F9) and face velocity.

Authoritative citations

1. ISO 16890-1/2/3/4: Air filters for general ventilation (particulate matter measurement and classification).
2. ASHRAE Standard 52.2-2017 (or latest): Method of Testing General Ventilation Air-Cleaning Devices for Removal Efficiency by Particle Size.
3. EN 779:2012 (historical reference; superseded by ISO 16890) — classification of air filters.
4. UL 900: Standard for Air Filter Units; DIN 53438 (F1) for fire behavior of filter media.