5. Filtering The Air: Removing Odours With Carbon Filters

The carbon filter has the capacity to filter the output of air from an extractor fan, making it odourless.

Air filtration can be needed when the air has nasty odours. To filter the filter the air an active carbon filter is used. The carbon filter has the capacity to filter the output of air from an extractor fan, making it odourless. They are made with an internal chamber filled with carbon granules.

HOW IS A CARBON FILTER MADE

Carbon filters have cylindrical form with one closed end and one open. On the open end a tapered flange is present to which the flexible ducting is connected, usually by a clip to connect hold them. The flexible ducting is then connected to the extractor fan.
The filter has metal perforated walls which on the inner chamber are then filled with active carbon. When the fan is in function, the air is forced through the walls and carbon filtering the air as it passes.

HOW DOES THE ACTIVE CARBON WORK

The term “contact time” indicates the quantity of time in which the air remains in contact with the carbon, greater the timer greater will be the odour treatment by the filter.
Thanks to its active carbon, the filter is able to neutralize odours produced by the flowers or plants.
The granules of carbon present in the filter can be replaced when finished. The filter can be placed on the extractors output even at a distance thanks to the flexible ducting.

HOW TO USE THE FILTER, THE EXTRACTION AND RECYCLE

There are two ways to use a carbon filter; extraction or recycle

• in the first case the air passes through the filter and is expelled outside the grow area
• in the second case (recycle) the air is filtered and put back into the cultivation area, so as to constantly filter the odours.

The substantial difference is in the case of the forced air extraction the air exchange is favoured( low co2 levels) which is an important element in indoor cultivation, whereas the second case is only for odour treatment.

CHOOSING THE CARBON FILTER

It is important to choose an extractor fan and filter with compatible capacities

• a filter with lower capacity than the extractor fan can cause excessive air to pass through, reducing the contact time and therefor performance of the filter.
• a filter with lower capacity compared to the fan reduces also the its capacity and raises the noise levels.
• We advise to choose a filter which has a slight superior capacity than the extractor fan.

WHEN TO CHANGE THE FILTER

The duration of the filter can depend on many factors. Generally the filter can last from 1200-3000hrs. In the grow room the filter will have an average durability of 3 cultivation cycles. The carbon and the filter can be changed when the run out, in fact there active carbon replacement sacks where youc an simply replace the carbon maintain the filters structure.