Phat Filter 12 in x 4 in. 200 CFM Scrubbing, 2 in Carbon Bed

How the Phat Filter Carbon Bed Is Built The bed is 2 inches thick and the carbon inside it is loose rather than pelletized. That distinction is the whole argument for this range. Pelletized carbon is bound together with glue, and every gram of binder is surface area that can no longer adsorb anything. Leaving the granules loose and packing them tightly keeps the pore structure available and raises the porosity of the bed as a whole. The carbon is virgin rather than reactivated, and it is steam activated at high temperature rather than chemically treated. An internal conical base spreads airflow through the full length of the bed instead of letting it short-circuit near the inlet. The outer aluminium mesh is 53 percent open area, so the housing itself adds very little restriction. Units are sealed straight after manufacture to hold the carbon's moisture content until it reaches the room. The body measures 12 inches on a 4 inch flange and the whole thing weighs 11 lb. A pre-filter comes with it to catch the coarse dust before it reaches the granules. Sizing a Carbon Filter for Scrubbing Against Exhaust The rating on the label is the part most people read wrong. That 200 CFM figure is a scrubbing rating, measured with the unit recirculating air inside a closed room. Run the same unit inline on an exhaust duct and the working figure is roughly 100 CFM. The air passes the bed once there rather than repeatedly. Halve the number before matching it to a fan. A fan that moves far more than the bed can handle pushes unscrubbed air straight past the granules, and the room still smells. The pre-filter is the part that determines how long the rest lasts. It catches dust before the dust blinds the carbon, and it wants washing or replacing on a schedule rather than when performance drops. By the time odour returns the bed underneath has usually taken the damage. Humidity is the other consumer of bed life, since water vapour competes with the compounds for the same adsorption sites. A filter run continuously in a wet room will not reach the life of one in a dry one. The unit carries a one-year warranty. Key Features Carbon bed: 2 inches thick, packed tightly rather than loosely filled Carbon form: Non-pelletized granules, with no glues or binders in the bed Grade: Virgin carbon, steam activated at high temperature Airflow path: An internal conical base spreads air through the full bed Housing: Outer aluminium mesh at 53 percent open area Packaging: Sealed after manufacture to hold the carbon's moisture Size: 12 inch body on a 4 inch flange, weighing 11 lb Included: A pre-filter ships with the unit Scrubbing rating: 200 CFM when recirculating inside a closed room Exhaust rating: Roughly 100 CFM when running inline on a duct Technical Specifications Specification Value SKU IGSPF124 Manufacturer International Grower Supplies, under the Phat name Body length 12 in Flange 4 in Carbon bed depth 2 in Weight 11 lb Carbon Virgin, non-pelletized, steam activated, RC 412 grade Binders None, so no glue blocks the pore structure Mesh Aluminium outer mesh at 53 percent open area Internal base Conical, to distribute airflow along the bed Scrubbing CFM 200 CFM Exhaust CFM About 100 CFM, which is the scrubbing figure halved Pre-filter Included Warranty One year from the manufacturer