Classification according to efficiency

The filters in common use have typical efficiencies and arrestances as listed in Table 17.1, according to Eurovent standards.

Table 17.1 Typical classification of arrestance and efficiency

Filter type

Face velocity m s“1

Pressure

Drop

Pa

Arrestance

%

Atmospheric dust spot efficiency %

Automatic

Viscous

1.87-2.50

100

80

Dry

2.54-3.58

125

70-80

Panel

Cleanable, viscous

1.9-2.7

80

65-80

Cleanable, dry

1.72

95

70-76

Disposable

1.8-3.78

135

70-89

Bag

Low-efficiency

3.78

220

30-50

Medium-efficiency

3.78

220

55-90

High-efficiency

2.54

220

90-97

Absolute

Low-efficiency

1.40

110, 750

95

Medium-efficiency

1.26

250, 750

99.7

High-efficiency

1.26

250, 875

99.997

Electrostatic Agglomerator with storage section

2.54

100

90

Notes

1. The figures are based on averages of manufacturers’ data.

2. Where two pressure drops are given they are for the clean filter and the dirty filter.

3. A single pressure drop represents an average figure.

4. Absolute (ULPA) filters with efficiencies as high as 99.999995% are also possible.

Posted in Engineering Fifth Edition