Electrical Considerations In Cleanroom Engineering

Electrical is a major component of cleanroom engineering or cleanroom design. Having sufficient electricity to operate the cleanroom hardware and equipment is critical. Properly sizing the electrical system so it meets current and future needs of the cleanroom will help avoid major expenses when equipment is added or replaced in the future. Many cleanroom projects include dedicated new electrical panels for the cleanroom to provide sufficient circuits to power all the elements of the cleanroom and the equipment in the cleanroom. The cleanroom hardware consuming the largest amount of electricity are typically the HVAC system, HEPA filtration and lighting.

HVAC is typically the largest cleanroom hardware user of electricity in the cleanroom. The HVAC system is most commonly DX split system with compressor and air handler. They use 230V and 480V power. Very large cleanrooms may use a boiler chiller system. 

Cleanroom Lighting is another major user of electrical power. Currently flat panel LED lights or tear drop LED lights are the most common choice for cleanroom lighting.  Almost all LED light fixtures are universal voltage.

HEPA fan filter units are a big user of cleanroom power. The higher the cleanroom class the more HEPA fan filter units will be required. An ISO6 /class 1000 cleanroom will require 9 times the number of HEPA fan filter units as an ISO6/class 100k cleanroom. That is because an ISO6 cleanroom does 180 air changes per hour while an ISO8 cleanroom only does 20 air changes per hour. HEPA fan filter units are available in 115V, 208V and 277V.  Selecting the higher voltage units reduces the amount of current needed. Another option is to use DC motor HEPA fan filter units which use less current for the same voltage.

Convenience outlets are a necessity in cleanrooms and required by building code. They are typically dual outlet 115 volt and can be placed in walls, floor or ceiling.

Other possible cleanroom hardware that are not in every cleanroom but need electrical power include humidifiers, dehumidifiers, deionizing systems, exhaust air systems and drain pumps.  

Emergency power or backup power is typically required in larger cleanrooms.  It can be supplied by battery or generators. Emergency lighting and emergency ventilation are most common application.

A comprehensive list of equipment going into the cleanroom along with electrical voltage and current requirements for each piece of equipment is critical to a good cleanroom electrical design. OSHA recommends that permanent equipment be hardwired. Most cleanroom equipment is 115V, 230V, 277V 3 phase, or 480V 3 phase.  Portable or smaller size equipment can use electrical outlets located in wall, ceiling or floor.

It is critical that cleanroom users design-in additional electrical capacity to allow for future addition of equipment or changes in the type of cleanroom equipment.

ESD (electrostatic discharge) is a major concern in semiconductor and electronics cleanrooms as it can easily damage the computer chips or electronic devices being manufactured. Installation of SD (static dissipative) cleanroom flooring and static dissipative modular walls is done to address this problem.

Some companies use air ionizers to neutralize static caused by the HEPA fan filter units.

Electrical is a major component of cleanroom engineering or cleanroom design. Having sufficient electricity to operate the cleanroom hardware and equipment is critical. Properly sizing the electrical system so it meets current and future needs of the cleanroom will help avoid major expenses when equipment is added or replaced in the future. Many cleanroom projects include dedicated new electrical panels for the cleanroom to provide sufficient circuits to power all the elements of the cleanroom and the equipment in the cleanroom. The cleanroom hardware consuming the largest amount of electricity are typically the HVAC system, HEPA filtration and lighting.