Phat Filter 39 in x 12 in | 1700 CFM Scrubbing, 12 in Flange

Sizing the Biggest 1700 CFM Carbon Filter in the 39 in Range Same body length as its 8 in and 10 in siblings, wider bore, more carbon. The printed 1700 CFM is the scrubbing figure, for air recirculated inside a room. Run it inline on an exhaust fan and you halve it to roughly 850 CFM. That lower number is the one your fan has to match. Getting this backwards is how a room ends up under-ventilated with the right filter in it. What a 12 inch Carbon Filter Asks of the Room Two things, and both are physical. The flange is 12 in, so the ducting has to match or you are adding a reducer. A reducer on the biggest filter in the range throws away the airflow you paid for. The second is weight. This one lands at 76 lbs empty, which is more than either sibling and more than most tent frames should ever carry. Hang a 12 inch carbon filter off rated hardware into building structure, not off poles. Inside it is virgin activated granular carbon, packed loose with no glues or binders. None of the adsorption surface is wasted holding pellets together. A conical base spreads air down the full body rather than loading the inlet end. The aluminum outer mesh keeps 53% of its area open so the filter adds little static pressure. A prefilter is included and it is a service item. Filters ship sealed, which holds the carbon moisture the material needs. Key Features 1700 CFM scrubbing, roughly 850 CFM exhaust: Halve the printed rating for inline use, then size the fan against the lower figure. 12 in flange: Match it with 12 in ducting. A reducer here gives back the airflow this size exists to provide. 76 lbs empty: Heavier than the 8 in and 10 in bodies. Rated hardware into structure, never off tent poles. Virgin granular carbon, non-pelletized: No glues or binders occupying surface that should be adsorbing odor. 53% open aluminum mesh: Over half the outer surface is open, so the filter itself adds very little static pressure. Conical base and prefilter included: Air spreads down the full body, and the prefilter takes dust before the carbon does. Technical Specifications Specification Value Model IGSPF3912 Length 39 in Diameter 12 in Flange 12 in Scrubbing Rating 1700 CFM Exhaust Rating Approx 850 CFM (half the scrubbing figure) Carbon Virgin activated granular, non-pelletized Weight 76 lbs Prefilter Included Base Internal conical for even airflow Outer Mesh Aluminum, 53% open area Packaging Sealed after manufacture to retain carbon moisture Warranty 1 year