12x20x12 AAF Flanders Varicel MERV 11 Air Filter – Single Header, Deep-Frame, 1 Unit

Description

This 12″ × 20″ × 12″ AAF Flanders VariCel filter (part number 331-953-191) delivers MERV 11 filtration in a rigid extended-surface construction for commercial and industrial HVAC.

The classic VariCel uses dual-density media and rigid construction to deliver consistent high-efficiency filtration across variable airflow, turbulent conditions, and high humidity.

When VariCel is specified

• Variable air volume (VAV) commercial HVAC — rigid construction holds pleat geometry across the full airflow range
• High-humidity environments — moisture-resistant frame won’t delaminate or warp
• Turbulent airflow — reinforced construction handles velocity variation
• Specialized applications — paint-booth diffusion filters, cleanroom pre-filters, cannabis cultivation

Design and construction

• Media: Dual-density extended-surface synthetic or microfiberglass (MERV-dependent)
• Frame: Rigid metal and board composite construction
• Header: Single Header
• Efficiency rating: MERV 11 per ASHRAE 52.2

What MERV 11 captures

Fine dust, pollen, pet dander, mold spores, smoke particles, and smaller allergens. MERV 11 is the standard recommendation for households with allergies, asthma, or pets, and is commonly specified for commercial office spaces where indoor air quality is a priority. Confirm your system can handle the slight increase in static pressure compared to MERV 8.

Need help with sizing or cross-reference?

If you’re replacing an existing filter from a different manufacturer or need help matching the spec, send us your current part number and we’ll confirm the exact match.

Spec sheet

Download VariCel spec sheet (PDF)

Also worth considering

Shopping on price? Our house brand PrimeShield Advanced (MERV 11) covers the same efficiency tier across common residential and commercial sizes and is usually the better value. Choose this branded option when your equipment spec sheet or facilities team calls for it specifically.

Questions on fit, quantity, or a commercial quote?

Need a size that isn’t listed, a different pack count, or a quote for a commercial order? Get in touch — we handle facilities and commercial orders daily and can usually match or beat distributor pricing.

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