Basic Documentation
Table Of Contents
- About this Application Guide
- Chapter 1–Introduction
- Chapter 2–Goals of the Laboratory Environment
- Chapter 3–Unique Ventilation Needs of a Laboratory Facility
- Chapter 4–Ventilation Systems Classification
- Chapter 5–Laboratory Facility Exhaust Systems
- Chapter 6–Laboratory Containment Units - Ventilation
- Chapter 7–Room Ventilation, Makeup Air, and Pressurization Control Systems
- Chapter 8–Laboratory Temperature and Humidity Control Systems
- Chapter 9–Laboratory Emergencies - Ventilation System Response
- Chapter 10–Laboratory Ventilation System - Validation
- Chapter 11–Laboratory Ventilation System - Commissioning
- Glossary
- Index
Chapter 6–Laboratory Containment Units - Ventilation
Table 3. Comparison of Biosafety Cabinet Characteristics (Continued).
Class and
Type of
Biosafety
Cabinet:
Class I
Class II
Type A
Class II
Type B3
Class II
Type B1
Class II
Type B2
Class III
Cabinet
exhaust
arrangement:
HEPA
filtered
cabinet
exhaust air
may be
returned to
room or
discharged
outdoors
via a hard
duct
connection.
HEPA
Filtered -
30% of the
cabinet’s
internal
airflow air
may be
exhausted
into the
room or
discharged
outside via
a canopy
connection.
70% is
recirculated
within the
cabinet.
HEPA
Filtered -
30% of the
cabinet’s
internal
airflow is
normally
discharged
outside via
a canopy
connection.*
70% is
recirculated
within the
cabinet.
HEPA
Filtered -
70% of the
cabinet’s
internal
airflow is
normally
discharged
outside via
a hard duct
connection.
30% is
recirculated
within the
cabinet.
HEPA
Filtered -
100% of
the
cabinet’s
airflow is
discharged
outside via
a hard duct
connection.
No air is
recirculated
within the
cabinet.
HEPA Filtered
-
100% of the
cabinet airflow
is discharged
outside via a
hard duct
connection.
No air is
recirculated
within the
cabinet.
Cabinet
exhaust air
allowed to be
recirculated
back into the
laboratory
room:
Yes -
(Class I
cabinets
are not
typically
arranged to
re-circulate
exhaust air
into a room.
Yes
No
No
No
No
Environmental
protection for
air exhausted
from cabinet:
Optional
HEPA Filter
HEPA
Filtered
HEPA
Filtered
HEPA
Filtered
HEPA
Filtered
HEPA Filtered
Room makeup
air
requirements:
Must equal
the amount
exhausted
outdoors.
Must equal
the amount
exhausted
outdoors.
Must equal
the amount
exhausted
outdoors.
Must equal
the amount
exhausted
outdoors.
Must equal
the amount
exhausted
outdoors.
Must equal
the amount
exhausted
outdoors.
Nominal air
consumption
rates based
on a 6 foot
wide cabinet:
8 in. High
Opening
300 cfm
10 in. High
Opening
375 cfm
(Assuming
all outside
exhaust)
8 in. High
Opening
210 cfm
10 in. High
Opening
265 cfm
8 in. High
Opening
280 cfm
10 in. High
Opening
355 cfm
8 in. High
Opening
410 cfm
10 in. High
Opening
515 cfm
8 in. High
Opening
900 cfm
10 in. High
Opening
1,000 cfm
120 cfm
nominal
** If a cabinet is used in conjunction with chemicals and/or radionuclides, the exhaust connection should be by a hard
duct connection.
44 Siemens Building Technologies, Inc.