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These special purpose rooms, in middle and secondary schools, may require fume hoods with special exhaust systems. A makeup air system may be required if there are several fume hoods within a room. If there are no fume hoods, a room exhaust system may be required for odor removal, depending on the type of experiments conducted in the room and whether animals are kept within the room.
The filtration for the air supply depends on the requirements for the laboratory. Conventional educational facility chemistry and physics laboratories13 commonly apply 30-35% prefiltration and 85% final efficiency dust spot efficient filters (per ASHRAE Standard 52.1). Outside air ventilation for these areas (based upon 30 persons per 1,000 square feet) should be 20 CFM per person. For applications allowing reduction of outside air in laboratories, please consult your local Farr Representative.
If the facility has laboratories of special needs,additional considerations must be made for special programs. High-efficiency particulate air (HEPA) filters should be provided for special spaces where research materials or animals are particularly susceptible to contamination from external sources. HEPA filtration of the supply air is necessary in such applications as environmental studies, specific pathogen-free research animals, nude mice, dust-sensitive work and electronic assemblies. In many instances, biological safety cabinets or laminar flow clean benches (which are HEPA filtered), rather than HEPA filtration for the entire room may be used. Please consult your Farr Representative for more information on these specialized applications. Any associated storage and preparation rooms are generally exhausted continuously to remove odors and vapors emanating from stored materials. Adequate ventilation for these areas is essential. Additionally a local exhaust fan with a wallmounted on-off switch may be needed for the occasional removal of excessive odors.
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