How often do I change the pre-filters in my HEPA units?
The pre-filters in your HEPA unit catch the larger particles in the air, what’s referred to as “hardballs and softballs.” They do the heavy work. Generally the pre-filters should be changed every three to six months. It is important to consider your environment in determining the frequency.
If your cleanroom sits in the middle of a warehouse or manufacturing area, your changing cycle is closer to three months, or maybe even more frequently. If your cleanroom sits in a pharmacy area, the environment will be cleaner. You can increase your change cycle to as long as six months.