Odour Filter - How to choose?
How do you choose an odour filter, and what should you watch out for when choosing one? That is a common question, and in this article I will try to give you a few reference points to help you find your way around.
What capacity should an odour filter have? - The capacity of an odour filter is stated in the same way as for fans, and it is the ability to clean a certain amount of air per hour of operation, stated in m3. That is, m3/h. You always need a filter with a higher capacity than the maximum output of the fan; otherwise, there is a risk that it will be “blown through” and the filter will start letting odours through, even though it is otherwise perfectly fine. 
How much more powerful can an odour filter be? - In theory, there is no limit. If you use a filter with a capacity of 4,000 m3 on a fan with an output of 800 m3, the setup will work, but the filter will be enormous and you will probably have a space problem. In practice, filters with a capacity 10-50% higher than the maximum output of the fan used are usually employed. For our case of an 800 m3 fan, a filter with a capacity from 880 m3 to 1,200 m3 is suitable. The higher the maximum capacity you choose, the longer the filter will last.
How long will the filter last? - This question is very difficult to answer; it is usually stated in the range between 6 months and 2 years, depending on the chosen filter series and its intended purpose. Overall, the filter’s lifespan is affected by 3 factors.
- The first is the amount of activated carbon in the filter,
- The second is the quality of the carbon, and its “tamping” so that the gaps are always even and no air pockets form, for which manufacturers use special tools.
- The last, and very important, is the “dirtiness” of the air that the filter is meant to clean. If the odour is strong and there is a lot of dust in the air that clogs the filter, you may need to replace the filter every few months; if the odour is mild, the filter may last significantly longer than its stated lifespan.
How do you connect the filter? - Air is always drawn through the filter so that the fan draws in already clean air. Filters are also usually made so that there is a coarse fabric on the outside that catches larger impurities - (this fabric can be replaced or even shaken out when the air is very dirty) and the air cleaned in this way is then filtered by activated carbon. If you connect the filter the other way round, meaning you blow air through the filter, large particles in the air will clog the activated carbon and significantly reduce its lifespan, as well as that of the fan, which is better off drawing in clean air.
Is it possible to replace the carbon in the filter and thereby extend its lifespan? - Theoretically yes, but because replacing the carbon is not just a matter of pouring out the used carbon and pouring in new carbon, but also very much about placing the carbon in the filter so that no air pockets form and at the same time the carbon is not “tamped” too much and the filter permeability is not reduced too much, and thus its real capacity. When replacing activated carbon at home, it is therefore necessary to count on the fact that the filter may work, but the filter parameters will be significantly worse than those of a new, originally manufactured filter.
We also recommend:
- You can find a wide range of odour filters here.
- Prima Klima Carbocone filters with extended lifespan
- Quiet WHISPERBLOWER fans
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