It seems that everyone has a carbon filter on the market today and honestly they all are a copy of the first ones created in 1987 in the Netherlands. By what’s now known as “The CF group”
I first heard of them in the early mid 1990’s I was sent over to Netherlands, Germany to meet the creator and tour both the filter factory and Ruck fans in Germany. Both of those facilities were amazing even back then the Ruck fan Factory was automated activate a program and the robotics picked up a piece of sheet metal put it on the line and out the other end came a Fan!
Amsterdam wasn’t bad either LOL
Amsterdam is a trip
I was actually at the time part of the team than first introduced the filters to North America, before that it was all about ozone generators, odor masking agents Ona blocks and other scent producing agents that people employed to mask or deal with Stink and odor.
If you remember ozone generators you probably know the nightmare they were both from a end user dealing with breakdowns or your neighborhood smelling like ozone or as a retailer dealing with the nightmare of ozone generator warranty returns. LOL
Don’t get me wrong Ozone has its place and the technology has come a LONG way in the past few decades, its just really not ideal for odor control in a horticultural application.
I traveled all over Canada, the United States and several places in Europe to trade shows, manufacturers learning about and introducing people to the beauty of activated carbon filters and inline fans. The indoor gardening scene is a photocopy industry they see it and they copy it, but what you make things out of matters, that’s the rub, and why a lot of knockoffs do not pass muster.
There is a lot of hype and sales BS that is attached to every filter ad I’ve seen most making claims that their product is better than everyone else. Some claim that the build of the filter makes theirs better showing exploded views of the pre-filter, the outer metal mesh, the activated carbon, the inner metal mesh etc. I’m going to let you in on a little secret there is only 1 and a half of those that actually matter.
I think they might mean “Good Filtration”
A carbon filter is all about the activated carbon and specifically two characteristics of the activated carbon. The type of carbon they use and the amount of carbon used.
Think of carbon as a sponge but different types of carbon have different sizes of holes (pores) and that makes a huge difference in what and how much those pores can capture and contain. if the pores are too small the odor (voc’s volatile organic compounds) bounce right over them and you get gank out the end of your ducting. If the pores are too big the VOC’s drop in and bounce out again resulting in gank out the other end.
The depth of the carbon bed matters too (this is in the how much carbon category) but most filters are direct copies of the first ones and usually follow the same build dimensions) if the bed is too thin they do not last long at all if too deep they have a severely reduced air flow.
Like I said its the carbon you are buying that’s what adsorbs the VOC’s the stink and holds it and it holds it until the pores in the carbon get too full to hold any more so unlike other methods of odor control they don’t just suddenly FAIL its a gradual thing a little smell at a time affording you time to start thinking replacement.
I might be a little biased with the type of carbon I prefer but I’m educated enough to realize that there are options usually with varying degrees of effectiveness or durability. Different carbons are created and classified for different uses. For example a carbon that is good for removing odor will in all probability not be effective for say removing chlorophyll out of a solvent solution, the method most used to make some plant matter extractions go from dark green to more of a honey color.
This is because as I’ve said the pore sizes and make up are different and why companies like Norit produce many different types of activated carbon from many different starting materials, combinations and configurations pellets to powders coal to coconut.
And for the record the guys at Norit will blow your freaking mind if you start talking activated carbon with them.
The “half” portion of my statement is the pre-filter usually a white quilt batting type material its much more industrial than what you find in the average blanket but the concept is the same and it has one job, catch the dust in the system BEFORE it is run through the carbon and clog up all those preciouses odor capturing pores.
A few things prematurely lessen the life of a carbon filter dust, high humidity, and chemical, waxy, petroleum type VOC’s. So high humidity and things like Sulphur burners, aerosol pest control, masking scents, anything like those that can go through the filter and clog the activated carbon.
The pre-filter is important for what it does its also fully cleanable and you can do it usually many times it will get a little frayed but as long as it still has some depth its functional so you can wash or vacuum them. or just hose them down and hang them to dry.
Carbon filters are also ALWAYS WORKING it does not matter if they are in line with a fan pushing or drawing air through them or sitting in the basement or closet waiting until the next cycle. If the carbon is exposed to air it is working and will adsorb VOC’s simply sitting there so if you want to extend the life of the filter wrap it up in something like Saran wrap when its not in use. the sides and the intake should all be covered this way it will last twice as long as if you just let it run all the time or left it unwrapped.
Try to avoid purchasing used filters as you cannot really tell how much its been used pop a new pre-filter on an old filter it looks pretty dam new unless you have a microscope and know what to look for you cant tell if its almost spent.
You do need to match your fan CFM to the filter size, this is important so you give the air enough time to react with the activated carbon if the air is going through too fast you will get gank (stink) out the other end of the ducting if the filter is too small it will constrict the fans ability to move enough air to actually do its main job and get the heat out.
Pro-Tip: Activated carbon used in this capacity does not actually die. In actuality its like a sponge and will continue to work until the compartments (pores) in the carbon are filled up or blocked in such a way that no more VOC’s can be adsorbed. Most often this is dust or volatile organic compounds oils and such off the plants thats gone airborne. Think of a fart, air passing out of your body would have no smell at all except that on its way out it picks up microscopic portions of shit and that shit combined with the air creates the nasty smell we associate with farting.
Ok so now your grossed out but the analogy is the easiest way to describe the VOC compounds that fill up the carbons pores.
Now the carbon is fairly hard at least harder than the VOC compounds it adsorbes it also has a much much higher tolerance to heat, SO if a person wanted to reuse the carbon they could stick it in an oven and crank it up to as high as the oven allows most often around 500 deg and if left the voc’s would be destroyed and once cooled it could be used again and again.
The downsides are of course the packing and unpacking of the carbon and that the smell of it being cooked off is going to have to go somewhere and it will be in the area your oven is and unless vented well it will stink up the joint.
this cooking off has also been done in larger outdoor barbecues with success. The carbon in any quality filter use pelletized carbon and is more robust and tends to react better to this treatment, also quality filters are packed on vibrating tables so the carbon is seated really well and minimizes air gaps that allow stink to pass through, this can be difficult to reproduce at home though one could probably use a large vibrating sander.
If you are drawing air in from an outside source through an air cooled light and then right out the other side outside the growing environment you probably do not need a filter at all.
With all the choices on the market it can be difficult to decide who to go with and I cannot say I have tried them all I have however been around long enough to know who the major players are and where they popped up in the chain. I do know that Canfilters.com made a quality product and was and will always be the Original carbon canaster filter. They were once a local Kootenay company (in north America) and had distribution hubs all over North America.
Now however the only truly “local” Kootenay” company is Kootenay Filters and I understand that they are cut from the same cloth as Can-filters you can find them here.