The application makes the difference.
Generally speaking the protective ventilation of the operator cabin needs to offer the same type of protection as a gas mask (respirator).
This means, it needs to provide breathing air free from any hazardous contamination, such as airborne particles, fungal spores, bacteria, foul odors, dangerous fumes and toxic gases.
Any filter has only a specific holding capacity. As soon as this capacity is reached, the effectiveness of the filter will decrease and the correct function of the protective ventilation system is not guaranteed anymore.
However, it is not possible to generally determine the maximum filter life, since it largely depends on the existing ambient conditions. SEKA has comprehensive experiences in this filed and is able to supports its customers.
Each protective ventilation system from SEPA comes with a control terminal for monitoring and operating the system. An easy-to-read display at the control terminal constantly indicates the present load condition of the dust filter. As soon as the filter has reached its limit, the operator will receive a respective warning signal.
Independent from their load condition HEPA filters should principally be exchanged at least after one year of operation. This could take place as part of the mandatory annual UVV inspection of the system.
SEKA recommends the exclusive use of high-quality filters made from fiberglass mats.
Referring to the replacement of activated carbon filters there is also no general rule. Saturation of such filters cannot be determined by any simple means. Especially colorless and odorless substances are difficult to detect. Often this is the case after contamination of the breathing air inside the cabin is higher than the permitted level.
That is why SEKA supports its customers in choosing the right filter.