Basic Documentation

Table Of Contents
Chapter 5–Laboratory Facility
Exhaust Systems
Chapter 5 addresses the applicable configurations, components, materials, and
control requirements of laboratory facility exhaust systems as an aid to selecting and
designing the most appropriate exhaust system for a specific laboratory facility. It
includes the following topics:
Laboratory Exhaust Air
Exhaust System Expansion
Exhaust System Energy Recovery
Cleaning Systems for Exhaust Air
Proper Exhaust System Functionality
Centralized Exhaust Systems with Constant Volume Fans
Exhaust System Discharge
Laboratory Exhaust Systems - General Requirements
Specialty Exhaust Systems
The exhaust system of a laboratory facility can be viewed as perhaps the most
critical portion of the overall ventilation system in terms of maintaining occupant
health and safety. There are many possible types and configurations of exhaust
systems for laboratory facilities. Every exhaust system must be designed and
configured to reliably remove contaminated air and discharge it in a manner that
prevents it from remaining hazardous to the facility or surrounding properties.
Laboratory Exhaust Air
Even if the air exhausted from laboratory rooms, biological safety cabinets, storage
areas, chemical fume hoods and other specialized exhausts is filtered by HEPA type
filters or put through sophisticated air washing or cleaning systems, it could still
contain some harmful or at least undesirable substances. Standards organizations
strongly recommend, and some local jurisdictions require, that laboratory exhaust be
discharged directly outdoors and not be recirculated. However, some local
jurisdictions may allow re-circulating and thus reusing a portion of the laboratory
exhaust air if it is effectively filtered or washed to remove all harmful substances.
Although permissible under these circumstances, the economics involved and the
uncertainty that recirculated laboratory exhaust air is totally free of all harmful
substances renders the possibility of reusing laboratory exhaust air to as impractical
for the vast majority of facilities. Therefore, it is recommended that the reader
consider that all laboratory facility exhaust will need to be discharged outdoors. This
section addresses the issues and control requirements of laboratory exhaust
systems that are configured as a non-re-circulating system.
Siemens Building Technologies, Inc. 19