A 100 mm (4″) inline carbon filter for stopping odour at the point air leaves your space. Australian Virgin RC412 charcoal rated at 1200+ IAV in a 38 mm bed. IAV is the iodine adsorption value — how much odour the carbon can actually hold — and it is the number cheap filters quietly leave out, usually because they pair low-IAV carbon with a thin bed. Aluminium flanges and dual-layer galvanised steel mesh in a powder-coated gunmetal finish handle the humidity a flowering room produces, and the flanges reverse to give the filter a second life. Quick Bloom Lights is the official Australian importer: stocked in Sydney, shipped domestically.
1200+ IAV
Australian RC412 charcoal
Reversible
flip it to extend its life
The reversible flange is the feature to understand
Air does not pass through a carbon bed evenly. It loads the intake end hardest, so that end saturates and stops adsorbing while the far end is still largely unused. On a conventional sealed filter that is the end of its life — half the carbon is spent, the rest is wasted, and you buy a new one.
This filter unscrews at both ends. When odour starts getting through, take it down, remove the top and bottom flanges, turn the body around and reassemble it the other way up. The unused end of the carbon now faces the airflow and you get a substantial second stretch of service out of a filter you already own. It costs ten minutes and nothing else. This size is also available as a Refillable Carbon Filter Kit, which does everything this filter does and opens up to be repacked when the carbon is finally spent.
Matching it to your fan
Filter and fan should be the same diameter. Choking a larger fan into a smaller filter raises static pressure, drops real-world airflow well below the rated figure, and makes the fan louder rather than quieter. At 100 mm this filter pairs with a Cloudline S4 or T4. It is worth understanding the airflow figures, because a fan's and a filter's are not measured the same way: a fan's CFM is a free-air number taken with nothing attached to it, while a filter's is the airflow it passes while still scrubbing properly. Fit a filter and a few metres of ducting to an inline fan and its real delivery sits well below that free-air rating, which is why a fan's headline number and this filter's 210 CFM are not directly comparable. Running a notch or two below maximum is normal practice in any case, and it is quieter besides.
Not sure what size fan the space needs in the first place? Use our exhaust fan size calculator.
Don't run it before you need it
Here is advice that costs us a filter sale and saves you money: in early veg, leave the filter off. Veg is when humidity is highest and odour is lowest, and running a carbon filter through it is close to the worst thing you can do to one — the carbon spends weeks adsorbing water vapour instead of odour and its pores clog with moisture. Run the fan and ducting as normal for airflow, and fit the filter when odour appears or at the flip into flower once humidity comes down.
Full specifications
| Manufacturer |
AC Infinity Inc. |
| Product / model |
Duct Carbon Filter 4″ / AC-DCF4 |
| UPC |
819137020665 |
| Duct opening |
100 mm (4″) |
| Total dimensions |
300 × 177 mm |
| Carbon type |
Australian Virgin RC412 |
| Carbon grade |
1200+ IAV |
| Carbon bed depth |
38 mm |
| Maximum airflow |
210 CFM |
| Flange material |
Aluminium |
| Flange design |
Reversible |
| Mesh |
Dual-layer rust-resistant galvanised steel, gunmetal finish |
| In the box |
Filter, two machine-washable pre-filter cloths, two hanging straps |
Wash the pre-filter, never the filter. The cloth sleeve catches dust before it reaches the carbon, and a clogged pre-filter chokes airflow and shortens filter life. It is machine washable — wash and fully dry it every month or two depending on how dusty your space is. Water is the one thing guaranteed to ruin the carbon itself, so the filter body never gets washed.
FAQ
How long does it last?
Around 12 months is the usual working figure, and in favourable conditions growers report 18 months or more. Treat that as a guide rather than a guarantee: filter life depends far more on your environment than on the calendar. What shortens it is running the fan hard around the clock, a heavy odour load, dusty air, and above all high humidity — carbon adsorbs water vapour as readily as it adsorbs odour, so a persistently humid room ages a filter long before its carbon is chemically spent.
How do I know when it needs attention?
Odour is the signal. When smell starts escaping a space that previously contained it, the intake end of the carbon has loaded up — reverse the filter and run the fresh end. When odour returns after that, the bed is genuinely spent.
Should it be running during veg?
Usually not, and this is the advice that costs us filter sales. Veg combines the highest humidity with the least odour, so the carbon spends weeks adsorbing water vapour instead of smell, its pores clog with moisture, and you burn through filter life scrubbing air that had little in it to scrub. Run the fan and ducting as normal for airflow, and fit the filter when you actually need it — when odour appears, or at the flip into flower once humidity comes down. A filter introduced then goes into service with its full capacity intact.
Should it go on the intake or the exhaust side?
Exhaust, for odour control — the fan pulls air through the filter and out, scrubbing everything leaving the room. Filters can be run on the intake side to clean incoming air, but that is about dust and pollen, not smell.
Do I need to maintain it?
Only the pre-filter cloth, which is machine washable — see the note above. Never wash the filter itself.
What does 1200+ IAV mean?
IAV is the iodine adsorption value, a measure of how much odour a given weight of carbon can hold. Higher means more capacity and a longer service life. Cheap filters often use low-IAV carbon, a thin bed, or both, which is why they seem fine for a month and then stop working.
Is this genuine AC Infinity stock with Australian warranty?
Yes. Quick Bloom Lights is the official Australian importer and distributor for AC Infinity. Stock is held in Sydney, orders ship domestically, and warranty is handled here rather than through an overseas seller.
