The Essential Functions of Cleanroom Maintenance

Proper and regular heating, ventilation and air conditioning (HVAC) preventive maintenance on clean rooms is absolutely important, may it be a semiconductor or a biotechnology application.

From this, one of many cleanroom classes can be noted, depending on the said application. As a result, a number of rooms that needs air changes and filtration will be identified. And because most of the clean rooms function 24-hour a day and seven times a week, the maintenance can be categorised into two, the equipment maintenance and filter maintenance.

Two Parts of Maintenance Task

Equipment Maintenance

Any non-redundant cleanroom equipment maintenance will often require a planned shutdown. This gives a technician the necessary time to thoroughly inspect such stuff including the PP strap, bearings sheaves, and belts.

Keeping a spare parts inventory journal (may include medical pouch and cleanroom wipes) that is easy to find is a good idea because replacement of a contractor or worn belt can be accomplished without a subsequent interruption to the operation of the cleanroom.

The working frequency is best scheduled with the pre-filter maintenance but is often times dictated by the restrictions of a cleanroom.

Filter Maintenance

A key part of cleanroom support is filter maintenance, it is critical to keep the room within specification. Because the room operates in 24/7, it puts continuous flow through the filters, which cause them to foul faster than equipment that runs on a set time.

All High-efficiency particulate arrestance (HEPA) filters  are used in the cleanroom for the final cleaning of the conditioned air into space. These are usually preceded by high-density (Magnehelic metered) bag (or box) filters, which are then preceded by pre-filters.

And since HEPA filters are time-consuming and expensive to replace, it is very important to be diligent in the cleanroom supplies like bag (or box) filters maintenance that protects them. Because the bag (or box) filters are somewhat costly, it's also critical to frequently replace the pre-filters that protect the bag (or box) filters.

The usual schedule for a cleanroom maintenance particularly the minimum filter replacement could be the following: for HEPA filters, once every three years; for bag filters, one time per year; and for pre-filters, six times each year.

For any particular cleanroom, this schedule may need to be adjusted as a result of the percentage of outside air that is introduced into the physical location or the geographic of the building and the system.

Most of the time, the changes in frequency is influenced by fog or other climate-related conditions proximity to freeways, and nearby construction.

Further Information

A good preventive maintenance program is the key to providing maximum reliability with a minimum of shutdowns.

During the initial year of the cleanroom maintenance contract, the personality of a particular building in both equipment and filter frequencies is usually revealed.

Monitoring the changes in magnehelic readings on the bag (or box) filter housings, and how dirty the pre-filters are during service will definitely show the actual filter changes frequency.

In relation, closely working with the facilities personnel and the clean room occupants will help you identify the needed frequency of the equipment maintenance.