Keep your air fresh with our convenient subscription service. Carbon filters saturate quickly, so they need to be replaced regularly. Each filter has a finite number of binding sites, and when these sites become occupied, the filter can no longer capture chemicals. To make it easy, we'll send you new filters at the interval of your choice: 60 or 90 days. When they arrive, simply peel off the old Barnakls and stick on the new ones.

We recommend purchasing our 3-pack if your ceiling fan has three fan blades, while our 5-pack is perfect for fans with 5 or more blades. Our lightweight design will not interrupt air flow and blend seamlessly against the top of the fan.

Great question and a common one for air purification. The easiest way to test whether your Barnakl is absorbing particles from the atmosphere in your home is to weigh a filter when you receive it and keep that number somewhere you can remember. When it comes time to replace your filter, weigh it again. You will see an increase in weight of 15-30% after using it. The weight gain represents the chemicals and gasses the activated coconut shell carbon has attracted.

A Lot!

**LIST OF ADSORPTION ABILITY OF ACTIVATED CARBON FOR VARIOUS MATERIALS**

Some of the contaminants listed are specific chemical compounds. Some represent classes of compounds, and others are mixtures and of variable composition. The numbers given represent typical or average condition and might vary in specific instances. Activated charcoal capacity for odors varies somewhat with the concentration in the air with humidity and temperature.

**KEY TABLE**                                          

1. = Excellent
2. = Good
3. = Poor
4. = Not Recommended   

Acetaldehyde 3, Butyne 3, Acetic Acid, Butyraldehyde 2, Acetic Anhydride 1, Butyric Acid 1, Acetone 2, Camphor 1, Acetylene 4, Cancer Odor 1, Acids 2, Caprylic Acid 1, Acrolein 2, Carbolic Acid 1, Acrylic Acid 1, Carbon Bisulfide 3, Acrylonitrile 1, Carbon Dioxide 4, Adhesives 1, Carbon Monoxide 4, Alcohol 1, Carbon Tetrachloride 1, Alcoholic Beverages 1, Cellosolve 1, Amines 3, Cellosolve Acetate 1, Ammonia 3, Charred Materials 1, Amyl Acetate 1, Cheese 1, Amyl Alcohol 1, Chemicals Amyl Ether 1, Chlorine 3, Animal Odors 2, Chlorobenzene 1, Anesthetics 2, Chlorobutadiene 1, Aniline 1, Chloroform 1, Antiseptics 1, Chloro Nitropropane 1, Asphalt Fumes 1, Chloropicrin 1, Automobile Exhaust 2, Cigarette Smoke 1, Bacteria 2, Citrus and Other Fruits 1, Bathroom Smells 1, Cleaning Compounds 1, Benzene 1, Coal Smoke 2, Bleaching Solutions 2, Combustion Odors 2, Body Odors 1, Cooking Odors 1, Bromine 1, Corrosive Gases 3, Burned Flesh 1, Creosote 1, Burned Food 1, Cresol 1, Burning Fat 1, Crotonaldehyde 1,
Butadiene 2, Cyclohexane 1, Butane 3, Cyclohexanol 1, Butanone 3, Cyclohexanone 1, Butyl Acetate 1, Cyclohexene 1, Butyl Alcohol 1, Dead Animals 1, Butyl Cellosolve 1, Decane 1, Butyl Chloride 1, Decaying Substances 1, Butyl Ether 1, Decomposition Odors 1, Butylene 3, Deodorants 1, Detergents 1, Garlic 1, Dibromeothane 1, Gasoline 1, Dichlorobenzene 1, Heptane 1, Dichlorodifluoromethane 2, Heptylene 1, Dichloroethane 1, Hexane 2, Dichloroethylene 1, Hexylene 2, Dichlorethyl Ether 1, Hexyne 2, Dichloromonofluormethane 2, Hospital Odors 1, Dichloro-nitroethane 1, Household Smells 1, Dichloropropane 1, Hydrogen 4, Dichlorotetrafluoroethane 2, Hydrogen Bromide 3, Diesel Fumes 2, Hydrogen Chloride 3, Diethyl Amine 2, Hydrogen Cyanide 3, Diethyl Ketone 1, Hydrogen Fluoride 3, Dimethylaniline 1, Hydrogen Iodide 3, Dimethylsulfate 1, Hydrogen Selenide 3, Dioxane 1, Hydrogen Sulfide 3, Dipropyl Ketone 1, Incense 1, Disinfectants 1, Indole 1, Embalming Odors 1, Inorganic Chemicals 2, Ethane 4, Incomplete Combustion 2, Ether 2, Industrial Wastes 2, Ethyl Acetate 1, Iodine 1, Ethyl Acrylate 1, Iodoform 1, Ethyl Alcohol 1, Irritants 1, Ethyl Amine 2, Isophorone 1, Ethyl Benzene 1, Isoprene 2, Ethyl Bromide 2, Isopropyl Acetate 1, Ethyl Chloride 2, Isopropyl Alcohol 1, Ethyl Ether 2, Isopropyl Ether 1, Ethyl Formate 2, Kerosene 1, Ethyl Mercaptan 1, Kitchen Odors 1, Ethyl Silicate 1, Lactic Acid 1, Ethylene 4, Lingering Odors 1, Ethylene Chlorhydrin 1, Liquid Fuels 1, Ethylene Dichloride 1, Liquor Odors 1, Ethylene Oxide 2, Lubricating Oils and Greases 1, Essential Oils 1, Masking Agents 1, Eucalyptole 1, Medicinal Odors 1, Exhaust Fumes 2, Melons 1, Female Odors 1, Menthol 1, Fertilizer 1, Mercaptans 1, Film Processing Odors 2, Mesityl Oxide 1, Fish Odors 1, Methane 4,
Floral Scents 1, Methyl Acetate 2, Fluorotrichloromethane 2, Methyl Acrylate 1, Food Aromas 1, Methyl Alcohol 2, Formaldehyde 3, Methyl Bromide 2, Formic
Acid 2, Methyl Butyl Ketone 1, Fuel Gases 3, Methyl Cellosolve 1, Fumes 2, Methyl Cellosolve Acetate 1, Gangrene 1, Methyl Chloride 3, Methyl Chloroform 1,
Phenol 1, Methyl Ether 2, Phosgene 2, Methyl Ethyl Ketone 1, Pitch 1, Methyl Formate 2, Plastics 1, Methyl Isobutyl Ketone 1, Poison Gases 2, Methyl Mercaptan 1, Pollen 2, Methylal 2, Popcorn and Candy 1, Methylcyclohexane 1, Poultry Odors 1, Methylcyclohexanol 1, Propane 3, Methylcyclohexanone 1, Propionaldehyde 2, Methylene Chloride 1, Propionic Acid 1, Mildew 2, Propyl Acetate 1, Mixed Odors 1, Propyl Alcohol 1, Mold 2, Propyl Chloride 1, Monochlorobenzene 1, Propyl Ether 1, Monofluorotrichloromethane 2, Propyl Mercaptan 1, Moth Balls 1, Propylene 3, Naphtha (Coal Tar) 1, Propyne 3, Naphtha (Petroleum) 1, Putrefying Substances 2, Naphthalene 1, Putrescine 1, Nicotine 1, Pyridine 1, Nitric Acid 2, Radiation Products 3, Nitro Benzenes 1, Rancid Oils 1, Nitroethane 1, Resins 1, Nitrogen Dioxide 3, Reodorants 1, Nitroglycerine 1, Ripening Fruits 1, Nitromethane 1, Rubber 1, Nitropropane 1, Sauerkraut 1, Nitrotoluene 1, Sewer Odors 1, Nonane 1, Skatole 1, Noxious Gases 2, Slaughtering Odors 2, Octalene 1, Smog 1, Octane 1, Soaps 1, Odors 1, Smoke 1, Odorants 1, Solvents 2, Onions 1, Sour Milks 1, Organic Chemicals 1, Spilled Beverages 1, Ozone 1, Spoiled Food Stuffs 1, Packing House Odors 1, Stale Odors 1, Paint and Redecorating Odors 1, Stoddard Solvent 1, Palmitic Acid 1, Stuffiness 1, Paper Deteriorations 1, Styrene Monomer 1, Paradichlorbenzine 1, Sulfur Compounds 1, Paste and Glue 1, Sulfur Dioxide 3, Pentane 2, Sulfur Trioxide 3, Pentanone 1, Sulfuric Acid 1, Pentylene 2, Tar 1, Pentyne 2, Tarnishing Gases 2, Perchloroethylene 1, Tetrachloroethane 1, Perfumes, Cosmetics 1, Tetrachloroethylene 1, Perspirations 1, Theatrical Makeup Odors 1, Pet Odors 1, Tobacco Smoke 1, Toilet Odors 1, Vapors 1, Toluene 1, Varnish Fumes 1, Toluidine 1, Vinegar 1, Trichloroethylene 1, Vinyl Chloride 2, Turpentine 1, Viruses 2, Urea 1, Volatile Materials 2, Uric Acid 1, Waste Products 1, Valeric Acid 1, Wood Alcohol 2,
Valericaldehyde 1, Xylene 1