5 Questions About Carbon Filters!
Those big, white cylinder things that indoor gardeners use to clean their grow room's air.
positioned at the beginning of an extraction system, hung up high in the
grow room, or the grow tent itself, attached to the sucking side of an
extraction fan with duct tape and a noise reducing clamp. A good carbon
filter effectively cleans your grow room's air, while creating the least drag
on your ventilation system. Air from your grow room is effectively pulled through
your carbon filter. It passes over a carbon bed, odors and particulates are
absorbed by the carbon, and the resulting purified air is either recirculated
within your grow room, known as air scrubbing, or extracted away. I'm going
to focus on carbon filters used for extraction purposes, as this is the most
common, and performance and quality are vital. Question One: Carbon Quality. The
most important issues are carbon source and quality. Carbon filters contain
either pelletized, or granulated carbon forms from sources such as coconut, or
amorphous carbon. Now, pelletized carbon creates the least drag due to its
uniform shape. However, its regularity exposes less actual carbon to the air
system than irregular-shaped granulated carbon. It's also generally much denser,
and heavier, and contains much smaller micro tight pores. Granular carbon
generally holds its natural shape as it was processed. It has much more surface
area per gram, and when chosen correctly, it has larger meso-type pores great for
catching large organic particles. Both pelletized and granular carbon can be
effective at removing odors and pollutants. However, it's the natural
porosity of the granular that is most important when it comes to removing
larger volatile organic compounds-- VOCs for short, or odors to the rest of us--
that derived from plant terpenes. It's worth noting that larger particles will
be broken down by pelletized carbon, but after a while, they will clog the
fissures in the passages through its much smaller micro pores. This
prematurely chokes the carbon, which stops it from absorbing-- think of a golf
ball trying to pass through a garden house--hey, I could have picked worse
scenarios--whereas carbon filters containing meso pore granular carbon are
less susceptible to this premature clogging and continue to eat VOCs for
longer. The extract carbon to look out for, that creme de la creme, so to speak,
is RC-48. This meso pore carbon can adsorb well
over 30% of its own weight in odors and particulates,
whereas lesser carbons can choke out just at 10% saturation. Question Two:
Pressure Drop. A good quality carbon filter should not reduce the static
pressure inside your ventilation system by
more than 30%, otherwise it could be bottlenecking your ventilation system,
and you risk a sort of "grow room suffocation," leading to heat and humidity
issues! Question Three: Duct Size. Remember to
choose a carbon filter and fan that are designed to work together! They should
have the same duct diameter so that they fit together easily, and the CFM's-- that's
cubic feet per minute-- of air moved should be well matched. If a filter is
rated at 800 CFM, and the fan you have required to cool your room is a 900 CFM
unit, you should choose a larger filter. Filters are precisely
matched to ensure that there's enough carbon to cope with the amount of air
you intend to pass through it. Pairing a carbon filter with a fan that is too
powerful will lead to insufficient contact time between the air and the
carbon bed, meaning owners have more of a chance of getting through. It will also
reduce the working life of your carbon filter, and your fan will suffer as well,
so avoid the mismatch, and choose the same or a larger filter match for the
fan. For a sizing guide, check out my other videos here. Question Four: Lifespan.
The working life of your carbon filter depends on the application, and a quality
carbon filter can last up to 2 years, or more, in most grow rooms.
Remember, overly humid grow rooms, i.e. 85% RH or more, will render your carbon
filter ineffective. Question Five: Are They Reversible? And what about inline filters?
Okay, that was two questions, but it's worth noting that carbon filters don't have to
be located at the start of your extraction system. Most, if not all, carbon
filters can be blown into, as well as being sucked through. As for reversible
carbon filters, this refers to changing the top collar and the base over in an
attempt to extend its natural life. I hear claims that only 65% of the
carbon inside filters, mostly the carbon towards the top of the filter, actually
gets used. However, in practical, rather than marketing terms, if the top half of
the filter starts to get full before the bottom, then the air will naturally find
the least path of resistance and flow through the bottom in good time. As for
inline carbon filters, these are designed to work in the middle of your extraction
system. They have duck ports at both sides, and air passes from one end
to the other. Be sure to note the arrows showing the recommended air flow. Finally,
I highly recommend buying an extra pre-filter, that's the white fabric
sleeve that fits on the outside of the carbon filter, then when you put it in
the washing machine every six months, you can fit a new spare right away. Also, make
sure you have some hanging hooks, fixture hangers, duct tape, and noise
reducing clamps to make installing your carbon filter a whole lot easier.
Okay! I hope you found this useful. If you have any questions, put them in the
comments below. Thanks for watching! Make sure you're subscribed! Adios amigos, this
is Everest, being extracted out.