HEPA Filter or High Efficiency Particulate Filter is an indispensable accessory in a clean room. We can see it anywhere in this controlled environment, especially for clean room equipment. And sure enough, it also applies to the Pass Box. So which Pass Box needs a HEPA filter and what are the precautions when replacing this filter for the Pass Box?

Which type of Pass Box has a HEPA filter?
If you have been following the articles of VCR Clean Room Equipment for a long time, you will surely know that Pass Box has two main types, Static and Dynamic. In addition, in Dynamic Passbox, we also have Air Shower Pass Box, laminar flow Pass Box or even VHP Pass Box (a device used for special disinfection). What they all have in common is the ability to clean. As for Static Passbox, they do not have a cleaning feature and they are basically only capable of interlocking and sterilizing with UV.

At this point, we probably already know which type of Pass Box needs HEPA Filter, right? That's Dynamic Pass Box

Dynamic Pass Box needs HEPA filter
See also: What is a Pass Box?

So why use HEPA filter in Dynamic Pass Box
Dynamic Pass Box was created to transfer items between two areas with different cleanliness levels and its purpose is to reduce the number of times the door is opened to reduce cross-contamination between clean rooms. Because when transporting between two environments with different cleanliness, the possibility of samples being contaminated when traveling from environment with lower purity. Therefore, the transmission cabinets need to be able to clean to deal with the contaminant particles on the specimen. That's also why Dynamic PassBox needs HEPA Filter.

Self-cleaning transmission cabinets draw air in and push it through HEPA filtration so that the air entering the work area is clean air, filtered for 99.99 particles 0.3 micrometers or larger. From there the passbox will clean the samples before putting them into the clean room.

See also: Types of Pass Box

What to pay attention when changing HEPA filter for Dynamic Pass Box
Here are some notes when replacing HEPA filters for cleanroom shipping boxes that you need to pay attention to:

When replacing the HEPA filter for a Self-Cleaning Shipping Box, special attention should be paid to opening, handling, and installation to ensure that the filter paper is intact, undamaged and in particular not touched. filter paper to avoid damaging the filter.
Before installing the HEPA Filter for Dynamic Pass Box, direct it to a well-lit place to see with the naked eye for gaps in the filter due to transportation or other causes. If it is punctured or has an opening, it cannot be used.
When replacing the HEPA filter, it is necessary to remove the control panel first, clean the dust, then take out the old filter and replace it with a new one (pay attention to the arrow mark on the filters must be placed in the right direction). - Match the filter outlet airflow direction), then reinstall the steps.

Structure of Pass Box with HEPA Filter
The HEPA filter is an important part of the Dynamic Pass Box, so proper maintenance and replacement is essential. While replacing we should pay attention to the above issues so that the filter replacement brings the highest efficiency.