Total solutions provider for cleanroom- IAQ Technology Malaysia

FAQ

Cleanroom is defined as " a specially construct room in which the air supply, air distribution, dust and airborne particle, room pressure, temperature and humidity are environmentally controlled to meet approppriate cleanliness."

2.Why we need Cleanroom?

In high technological industries such as electronics, optical and biological industries which the production quality is affected by the airborne particles or dust. Air filter being used in common HVAC system can never collect these particles, we also need to take control the temperature, pressure, humidity and others factors to make the room suitable for production. Industries that make Computer hardisk and microprocessor need to be produced under cleanroom environment. Also, in food prcessing, medical or pharmaceuticals, control the micro-organism is a key point to maintain the quality.

We cannot find the highest cleanliness Cleanroom any place in the natural world. Places like upper area of stratophere or center of pacific ocean can't even meet the cleanliness of middle class Cleanroom.

3.Where do all these tiny particles come from?

Human body is one of the biggest sources of particels generation, the quantity are different each other depending upon the person, kids of his movement, kind of his garment and others. For examples, human body generate 100,000 particles per minute when sitting of standing without movement while walking quickly will generate 10,000,000 particles per minute.

4.How big is a micron?

A micron is a millionth of a meter. Tiny, even compared to a human hair which is about 100 microns.

5.How to classified cleanroom?

Cleanroom can be divide into two kinds by application: Industrial Cleanroom and Biological Cleanroom. Biological Cleanroom with cleanroom function like Industrial Cleanroom, also need to control contamination density of micro-organism.

Cleanroom can be classified according to the level of cleanliness. We usually use U.S Federal Standard, which We messured the class of Cleanroom by the numbers of particle larger than 0.5 micron in diameter contained in one cubic foot of air. For example. Class 100 cleanroom contains fewer than 100 of such particle in one cubic foot. Beside US Federal standard, ISO 14644 also another type of classification. Tables below show the two standard.

Table 1: Airborne Particle Requirements for ISO 14644 and Federal Standard 209
ISO 14644-1	Obsolete Federal Standard 209	Number of particles per m ³ by micrometer size
ISO 14644-1	Obsolete Federal Standard 209	0.1μm	0.2μm	0.3μm	0.5μm	1μm	5μm
1	-	10	2	-	-	-	-
2	-	100	24	10	4	-	-
3	1	1,000	237	102	35	8	-
4	10	10,000	2,370	1,020	352	83	-
5	100	100,000	23,700	10,200	3,520	832	29
6	1,000	1,000,000	237,000	102,000	35,200	8,320	293
7	10,000	-	-	-	352,000	83,200	2,930
8	100,000	-	-	-	3,520,000	832,000	29,300
9	-	-	-	-	35,200,000	8,320,000	293,000

Table 4: Comparison of FDA, NASA, EU-GMP Standards
Cleanliness Class		FDA	NASA	EU-GMP
		CFU/m ³ (CFU/ft ³)	CFU/m ³ (CFU/ft ³)	CFU/ m ³	At Rest		In Operation
		CFU/m ³ (CFU/ft ³)	CFU/m ³ (CFU/ft ³)	CFU/ m ³	0.5 μm/ m ³	5 μm/ m ³	0.5 μm/ m ³	5μm/ m ³
A	100	-	-	<1	3,500	-	3,500	-
B	100	3.5 (0.1)	3.5 (0.1)	10	3,500	-	350,000	2,000
C	10,000	-	18 (0.5)	100	350,000	2,000	3,500,000	20,000
D	100,000	88 (2.5)	88 (2.5)	200	3,500,000	20,000	-	-

Note: The above information is for reference only. Please refer to the respective Standards for exact details.

6.How about our surrounding environment?

We can't find places with class 100 or higher in natural world. Stratosphere area is range from class1,000 to 10,000. On top of the mountain is about class 100,000. city area is class 1,000,000 while industrial area reach class 10,000,000.

7.How do cleanrooms stay clean?

In several ways. Cleanroom technicians wear special clothing that's designed not to shed or let particles escape. Often before entering the cleanroom, personnel will walk through an airshower which blows off any particles using high velocity air. And, in the cleanroom, places where dust could settle like ledges and moldings are minimized. We also create an airflow pattern called laminar flow that constantly cleans the air by directing and re-circulating it through special filters.

8.What is laminar flow?

It's when all of the air in a cleanroom is forced to move in the same direction and speed to a filter. One common example of laminar flow is when the air moves from the ceiling through the floor, is forced up through the walls to be filtered above the ceiling and then re-enters the room and continues the cycle.

9.What does HEPA filter stand for?

High Efficiency Particulate Air. These replaceable filters will catch almost 100% of particles as small as .3 microns.

10.What does ULPA filter stand for?

Ultra Low Penetration Air. These filters can remove almost 100% of particles as small as .1 micron from circulating air.

11.What exactly is an airshower?

It's a hallway or room leading to the entrance of the cleanroom. Often there is an airshower between the dressing room or gowning area and the main entrance to the cleanroom. In the airshower, high velocity air blows off debris that could contaminate the cleanroom environment. Sometimes de-ionizers are used to remove static thereby increasing the effectiveness of removing hair and lint.

12.What is a pass-through?

A pass-through (pass-thru) is a chamber that allows items to be moved between cleanrooms or between cleanroom and non-cleanroom areas. Less traffic in and out of the cleanroom means fewer chances for contaminants to enter. Pass-throughs can also be designed so that only one door will open at a time. This, in conjunction with higher air pressure inside the cleanroom, forces particles out when the inner door opens. Pass-box in one of the pass-through.

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