Active Air Carbon Filter, 12" x 39", 1700 CFM

Scrub Strong Grow-Room Smells Before They Leave the Room

Run enough plants under enough light and the air in the room starts to carry — through doorways, hallways, and eventually outside where neighbors and visitors can pick up on it. Once that smell escapes, there's no calling it back.

The Active Air Carbon Filter, 12" x 39", is built to catch it first. Air drawn through its 1.8" bed of virgin activated Australian granular carbon gives odor molecules and volatile organic compounds nowhere to go, so what comes out the other side is clean.

Rated for up to 1700 CFM, it's sized to keep pace with a serious exhaust run — and because it ships with a pre-filter and an attached flange, it's ready to mount the moment it's out of the box.

Key Features & Benefits

• Virgin activated Australian granular carbon — a premium media chosen for its density and surface area, giving it more capacity to trap odor molecules per pound.
• 1.8" carbon bed depth — deep enough to give air a real dwell time inside the media instead of rushing straight through it.
• Rated up to 1700 CFM — sized to keep pace with a 12" x 39" exhaust run without becoming the bottleneck in your airflow.
• Pre-filter included — screens out dust and loose debris before it ever reaches the carbon, so the bed stays cleaner longer.
• Attached flange, machine-packed housing — connects straight to ducting with no separate adapter, and the consistent pack means predictable performance.
• Powder-coated aluminum tops and bases — lightweight and corrosion-resistant, built to handle daily use in a humid grow room.

Who Should Use This Carbon Filter

This filter suits any grower running a 12" x 39" exhaust line who needs serious odor control — from a single tent pulling 1700 CFM to a larger room where keeping smells contained is part of staying on good terms with neighbors and landlords alike.

Matching It to Your Exhaust Setup

For best results, pair this filter with an inline fan rated near its 1700 CFM mark and 12" x 39" ducting so air moves through the carbon at the speed it's designed for — too fast and odor slips through, too slow and you lose airflow. Keep the included pre-filter on the intake side, and have the matching ACCF3912PF Pre-Filter on hand as a replacement once the original starts looking dirty.

Frequently Asked Questions

How long will this filter actually last?

Active Air rates this filter for up to two years of typical use, though heavy odor loads or dusty environments can shorten that window.

Do I still need a separate pre-filter?

One ships with the unit and is ready to use out of the box — keep a spare on hand so you can swap it in the moment the original starts looking dirty.

Will 1700 CFM cover my room?

That depends on your room's volume and how often you want the air fully exchanged — as a starting point, match the filter and fan CFM ratings to your duct size and adjust from there.

How is it mounted?

It connects directly to your ducting through its attached flange — no separate adapter required — typically positioned just ahead of your inline fan.

Can I tell when it needs to be replaced?

A clear sign is when odor starts slipping through despite a clean pre-filter — at that point the carbon bed has used up its capacity and it's time for a new filter.