Basic Documentation

Laboratory Ventilation Codes and Standards
Siemens Industry, Inc. 104
Topic Requirement(s) Commentary
Supply Air
Quality and
Filtration
(Continued)
C.7.5.g. The use of exposed fiberglass or any fibrous material that allows fibers to
break off into the airstream for interior duct lining or insulation is usually not allowed
for ductwork and air-handling units. Sound attenuators with suitable linings or other
approved means of noise control shall be used where required. Insulation and a
vapor barrier shall be installed on the outside of ductwork to prevent condensation.
C.7.5.j. Supply air for all laboratory systems shall be filtered on the upstream side of
fans with prefilters and high-efficiency afterfilters.
C.7.5.i. HEPA filters shall be provided in special laboratories where research
materials are Particularly susceptible to contamination from external sources.
ASHRAE, 2011 Handbook - HVAC Applications, Laboratories, Pg. 16.9
LABORATORY VENTILATION:
Laboratories in which chemicals and compressed gases are used generally require
nonrecirculating or 100% outside air supply systems. The selection of 100% outside
air supply systems versus return air systems should be made as part of the hazard
assessment process….
Filtration for the air supply depends on the requirements of the laboratory.
Conventional chemistry and physics laboratories commonly use 85% dust spot
efficient filters. Biological and Biomedical laboratories usually require 85 to 95% dust
spot efficient HEPA filtration. HEPA filters should be provided for spaces where
research materials or animals are particularly susceptible to contamination from
outside sources. HEPA filtration of the supply air is necessary for such applications
as environmental studies, studies involving specific pathogen-free research animals
or nude mice, dust-sensitive work, and electronic assemblies. In many instances,
biological safety cabinets or laminar flow clean benches (which are HEPA filtered)
may be used rather than HEPA filtration for the entire laboratory.
Institute of Laboratory Animal Research, Commission on Life Sciences, National
Research Council, Guide for the Care and Use of Laboratory Animals, Eight
Edition, 2011:
Page 141: Air handling system intake locations should avoid entrainment of fumes
from vehicles, equipment, and system exhaust. The type and efficiency of supply and
exhaust air treatment should be matched to the quantity and types of contaminants
and to the risks they pose. Supply air is usually filtered with 85–95% dust spot
efficient filters (ASHRAE 2011). In certain instances, higher efficiency filters (e.g.,
HEPA) may be beneficial for recirculated supply air and air supplied to or exhausted
from specialized areas such as surgical and containment facilities.
ASHRAE allows the laboratory supply air to be
comprised of a mixture of outside air and
recirculated (return) air from non-laboratory
areas In lieu of 100% outside air.
Chemical laboratories that require HEPA
filtered air for only part of the lab activities may
realize a cost benefit by utilizing localized
containment enclosures (that is, biosafety
cabinets, clean benches, etc.) that are
available with the required air filtration
provisions.