When Is the Best Time to Replace Your Carbon Filter?

best time to replace your carbon filter

Having a grow room is one efficient solution to developing cultivars under specific controlled conditions. Factors such as temperature, humidity, amount of hydration and lighting are just a few among the things that can be carefully regulated by the grower in order to help achieve its desired growth outcome.

One way to ensure this from happening is through the use of carbon filters or scrubbers. The importance of a carbon filter in a grow room is imperative as this basically facilitates the air purification and odor neutralization within the enclosed space. In that regard, the filter keeps the room free from debris, dust, pollen, mold spores, volatile compounds, airborne pathogens, and other contaminants that might potentially affect the growth of the plants.

However, just like any other cleaning devices, carbon filters can only do so much for your grow room until such time it reaches its maximum lifespan. In this article, we will particularly discuss how to figure out when is the best time to change or replace the air filters for your space. Furthermore, we will also tackle the procedures involved in installing a carbon filter.

How does carbon filter work and how to recognize if it is no longer working?

To start the discussion, let us first briefly tackle how does a carbon filter basically works and how to identify when is it not working anymore.

In this kind of technology, oxygen-treated charcoal or referred to as activated carbon is typically used. The primary mechanism of air purification via a carbon filter is through a process called adsorption. Whereby, the bed of carbon efficiently draws in the unwanted odor, airborne contaminants, and certain organic compounds circulating in the immediate surrounding of an enclosed space.

On the other end of the story, you can also easily tell if the carbon filter is no longer effectively functioning. The most obvious sign is when you are starting to smell the odor. That simply means that the carbon is no longer being able to absorb and trap the smell within the grow room. Thus, indicating the need for replacement.

There may also be times though that the growers themselves won’t be able to detect the odor as they are too used to the smell that it already becomes normal for them. In this case, it is helpful to ask someone else less familiar to do some sniffing on your behalf. 

How long does a carbon filter last?

Different brands and types of commercially available carbon filter kits may present diverse recommendations as to when it is ideal to replace. Nevertheless, it is generally best to change carbon filters every after 18 to 24 months of regular usage, and by that, it means when your ducting system is operating 24/7. However, the lifespan is expected to last even longer when the demand for filtration is subsequently lesser as well.

The table below shows the suggested lifespan of the carbon filter and other commonly used types of air filters:

Type of Filter Lifespan
UV lamps or bulbs 12 months
Pre-filters 6-12 months
Post-filters 6-12 months
Carbon foam filter 6-12 months
Activated carbon filter 12 -24 months
Non-sealed HEPA filter 6 – 12 months
Sealed HEPA filter 24 – 60 months

Read Also: Easy DIY Carbon Filter for A Grow Room

What are the factors affecting the lifespan of the carbon filters?

Technically, the carbon filter will continue to deliver effective results until such time the filter media becomes full. There are various considerations affecting the longevity of the carbon filter. Certain factors may include the following but not limited to: the quality of carbon used, the level of humidity, the filtration demand, the nature of the cultivars, and many other contributing elements within your plantation area.DIY Carbon Filter for A Grow Room

  • Carbon Quality

The carbon filter primarily depends on the carbon material itself to purify the air. Thus, the form and type you opt to use will have a direct correlation to its effectiveness. 

There are different types of carbon available in the market but not all of them are equally efficient for adsorption of contaminants. In this project, the activated carbon is widely known to be the most effective for this job.

There are two types usually used for air filters: the Pelletized and the Granulated activated carbon

The pelletized carbon comes denser and more uniform in shape. However, it is heavier and comes with lesser pores. The granulated activated carbon, on the other hand, appears as a loose grain measuring up to 3mm in size. It is lighter in density hence it is more capable of covering more surface area per gram than the pelletized version.

  • Carbon Density

Another important physical property to look out for is the actual density of the carbon. The idea here is that the lighter the density, the more pores it will have. Thus, the better is the capacity of the carbon to adsorb. 

The typical carbons available commercially have a density that ranges from 30 up to 60 grams per cubic centimeter. Denser carbon tends to have narrower pores which leave it with a lesser room to accommodate filtrates. The limitation in space makes it more prone to clogging that consequently diminishes the lifespan of the filter.

Meanwhile, carbon with lighter density features wider pores. That being said, the structure is spacious enough for small and large particulates to get trapped inside the carbon. On that note, this is more ideal for filtration purposes. 

  • Humidity

One drawback of activated carbon is its decreased efficiency to air purification when exposed to a highly humid environment. That is because the charcoal naturally has tendencies to draw in moisture. Given that scenario, the carbon’s pores are filled with more water instead of trapping the airborne contaminants and any untoward odor. 

In case your grow room has high humidity, then it may be best to acquire a dehumidifier to aid in controlling the excessive moisture in the atmosphere. In that way, the function of the activated carbon in terms of air decontamination and odor management is not disrupted.

  • Filtration demand

The nature of the cultivars itself also helps to determine how often will you need to replace your carbon filter.  Just like for instance, it is normal for aromatic plants to release more compounds into the air. As a result, the carbon filter is expected to get filled up easily and require more frequent changes.

How to prolong the lifespan of carbon filter?

  • Use high-quality activated carbon

Considering that activated carbon is the main component responsible for the air purification, it is just ideal to use one with high-grade quality. The Australian certified virgin charcoal is popularly known in the grow room industry as one of the most sought after in terms of quality excellence and longevity.

  • Use a pre-filter

The pre-filter is an essential component that greatly helps to extend the lifespan of the carbon filter. Its primary function is to capture dust and other large particles so that it will no longer reach the carbon bed and cause premature clogging of the pores. Depending on the environment, you may need to clean the pre-filter more often than the carbon filter. 

  • Use durable material for the body of the carbon filter

Apart from the carbon bed, it is also important to consider the material of the body or the skeletal structure itself of the device. 

Most often, the commercial carbon filters are made out of aluminum material. It is a popular choice mainly because it is lighter, has anti-corrosive properties, and much cheaper in cost. Durability-wise, however, it is not as strong as compared to other materials.

A galvanized steel, on the other hand, is heavier and sturdier than aluminum. Hence, it is expected to keep the body of your carbon filter last longer. The downside though for this material is its expensive price. 

  • Control the humidity

As mentioned earlier, the ability of the activated charcoal to decontaminate and neutralize the air is minimized under a highly humid environment. Typically, carbons have a maximum threshold between 70% up to 80% relative humidity. Although, as much as possible, it is still best to try to maintain lower than the said limit to ensure optimum performance. 

Furthermore, extremely high or low humidity also has a direct and detrimental impact on the nutrition and pace of growth of the cultivars. The table below shows the optimal range of humidity in a grow room based on the stage of the plant’s growth:

Plant Stage Optimal Relative Humidity 
Clone Stage 70%
Vegetative Stage 40% up to 60%
Flowering Stage 40% up to 50%
Final Flowering Stage 40% up to 45%

Without a shadow of a doubt, the importance of a carbon filter is indispensable in creating a conducive setup in a grow room. Hence, it is necessary to maintain it in its most favorable condition to continue to reap the expected benefits. 

However, in reality, there is really no exact time frame as to how long will the carbon filter last.  There are way too many variables that can potentially affect its longevity along the way. Recommendations from the brand may be a good basis but it the end, it is still best to stay sharp and trust your sense of smell.

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