4 Things You Need to Know When Building a Cleanroom

First, you must determine if a clean room is necessary. Cleanrooms are designed to maintain extremely low levels of particulates. These particulates can cause damage to sensitive items such computer components, Semiconductor fabrications, solar panels, batteries, and other sensitive products. They can come in many sizes and can even encompass entire manufacturing facilities depending upon the products being manufactured there. Contaminants, such as dust, and other airborne organisms can cause irreparable damage to these products, and cleanrooms are designed to defend against such contaminants. They are built specifically to manage and maintain a specific level of particulates that would not harm these products and typically have a cleanliness level quantified by the number of particles per cubic meter.

Once you’ve decided that building a cleanroom is required for the development of your products the first question that must be answered is which class of clean room is needed.

The current standard US and Canada is the ISO classification system ISO 14644-1. The lower the ISO class the requirements for cleanliness go up.

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ISO Class	Max. allowable particulate concentrations/m3a						209E Prior STD
ISO Class	=0.1µm	=0.2µm	=0.3µm	=0.5µm	=1µm	=5.0µm	209E Prior STD
ISO Class 1	10	-	-	-	-	-
ISO Class 2	100	24	10	-	-	-
ISO Class 3	1,000	237	102	35	-	-	Class 1
ISO Class 4	10,000	2,370	1,020	352	83	-	Class 10
ISO Class 5	100,000	23,700	10,200	3,520	832	-	Class 100
ISO Class 6	1,000,000	237,000	102,000	35,200	8,320	293	Class 1,000
ISO Class 7	-	-	-	352,000	83,200	2,930	Class 10,000
ISO Class 8	-	-	-	3,520,000	832,000	29,300	Class 100,000
ISO Class 9	-	-	-	35,200,000	8,320,000	293,000	Room Air

Second, once the classification is identified this will determine your layout and design. For example, ISO 8 does not require you to enter through an airlock, while ISO 6 does.

Cleanrooms maintain particulate-free air using an HVAC system which is at the core of every clean room. The system uses either HEPA or ULPA filters using an air flow principle known as the Laminar principle. The principle uses air which is forced in a single direction in a constant stream. The stream forces the air into filters in the room so they may be recirculated over and over again removing the particulates from the air.

Third, for the clean rooms to maintain its ISO level the air in the room will need to be swapped out over and over every hour throughout the day How many times will depend on the ISO level you wish to maintain. This is known as the ACH (Air changes per hour)

ISO Class	Air changes per hour (ACH)
ISO 8	10 to 25
ISO 7	30 to 50
ISO 6	60 to 150
ISO 5	150 to 250+

Fourth, once the ACH is established we can figure out air flow required within the clean room space. There are many factors to consider here but for our purposes we will ignore some of these for the moment, so we end up with a more simplified formula:

(Room Volume in cubic feet) x (ACH) ÷ 60 = CFM (Required Air flow cubic feet per minute)

For Example: Your space is 10Wx10Lx8H. Room volume is Length x Width x Height or 800 Cubic Feet. You want to maintain an ISO Level 6. You can plug in the ACH of 150. Your final formula is:

800 x 150 ÷ 60 = 2,000CFM

The CFM will help determine the number of filters would be required based on their capacity giving you the basic framework to determining what your space will look like.

These things will need to be kept in mind while developing the layout of your space. Q Source has experts available in the cleanroom construction to help guide you to your perfect clean room solution, please contact us.