Basic Documentation
Table Of Contents
- Introduction
- Applicable Definitions (Alphabetical Listing)
- Laboratory Safety
- Hazard Assessment
- Chemical Hygiene Plan
- Chemical Hygiene Responsibilities
- Fume Hoods
- When Required & Safe Usage
- Gloveboxes:
- Face Velocity
- Face Velocity Setback
- Size & ADA Compliance
- CAV (Constant Air Volume) Bypass
- CAV (Constant Air Volume) Conventional
- VAV (Variable Air Volume)
- VAV Diversity
- Automatic Sash Closure
- Safe Operation of Sashes
- Accessories, Services and Explosion Protection
- Ductless
- Auxiliary Air
- (Special Purpose) Perchloric Acid
- Room Air Cross Currents
- Minimum Exhaust
- Monitoring
- Selection Criteria and Performance Specifications
- Laboratory Design & Fume Hood Implementation
- Maintenance
- Periodic Testing
- Test Procedures
- Signage and Recordkeeping
- Shutdown Procedures
- Evaluating CAV (Constant Air Volume) Systems
- Evaluating VAV (Variable Air Volume) Systems
- Biological Laboratories
- Biosafety Level 1
- Biosafety Level 2
- Biosafety Level 3
- Biosafety Level 4
- Ventilation for Biosafety Level 1
- Ventilation for Biosafety Level 2
- Ventilation for Biosafety Level 3
- Ventilation for Biosafety Level 4, Cabinet Laboratory
- Ventilation for Biosafety Level 4, Suit Laboratory
- Containment Levels - Canada
- Containment Levels and Ventilation Requirements: Canada
- Biological Safety Cabinets and Classifications
- Biosafety Cabinet Applications
- Biosafety Cabinets – Installation and Safe Usage Recommendations
- Biosafety Cabinets – Certification and Safe Usage - Canada
- Biological Safety Cabinet Design, Construction and Performance Requirements
- Biosafety Cabinet Testing
- Ventilation Systems
- Local Ventilation -When Required
- Ventilation Rates for Animal Rooms
- Ventilation Rates for Animal Rooms
- Ventilation Rates for Biological Labs
- Ventilation Rates for Chemical Laboratories
- Ventilation rates for Storage areas
- Room Supply Air
- Supply Air Quality and Filtration
- Room and Duct Pressurization
- Human Occupancy, Room Temperature and Humidity
- Animal Rooms Room Temperature and Humidity
- Load Calculations
- Room Sound Level and Vibration
- Emergency Control Provisions
- Energy Conservation
- Monitoring
- Maintenance
- Periodic Inspection and Testing
- Periodic Inspection and Testing - Canada
- Test Records
- Management
- Exhaust Systems
- Configuration
- Leakage
- Components
- Manifolded Systems
- Air Velocity
- Stack Height and Discharge Location
- Operational Reliability
- Recirculated Air and Cross Contamination
- Materials and Fire Protection
- Commissioning
- Commissioning - Canada
- Referenced Publications
Applicable Definitions (Alphabetical Listing)
Siemens Industry, Inc. 11
Term Definition Commentary
Fume Hood:
Low Velocity
Fume Hood:
Response Time
Fume Hood:
Sash
Fume Hood:
Sash Design
Opening or Sash
Design Position
Fume Hood:
VAV
A fume hood designed to provide containment at a lower face velocity (typically 60 fpm
or less). Low flow fume hoods achieve their performance through various means that
include specific airflow/airfoil designs, unique baffle configurations and may also
incorporate internal apparatus (that is, fans, etc.) to achieve their stated performance.
This pertains to fume hoods equipped with variable air volume systems that control the
fume hood’s exhaust to always maintain the desired face velocity at a constant rate.
Response time is generally defined as the time that it takes to restore the face velocity
to within 10% of the desired rate after the completion of sash movement. The major
standards that cover laboratory ventilation system performance (ASHRAE 110,
ANSI/AIHA Z9.5 and NFPA 45, 2011) do not state a required minimum response time.
Recognized research on fume hood response time (An Approach to Determining the
Required Response Time for a VAV Fume Hood Control System, ASHRAE
Transactions 1990) states: “The result of this research indicates that tracer gas did not
escape the fume hood when control action was taken within 2 to 3 seconds…..”
The movable transparent panel(s), that enable access to the fume hood interior. When
access to the interior is not required, good safety practice requires the user to keep the
sash(es) closed to provide a protective barrier between the interior and fume hood user
and the other laboratory room occupants. Fume hood designs may incorporate single
or multiple sashes and the sashes may be arranged to move vertically (up and down)
or horizontal (sideways). Some fume hood designs (termed combination sash) consist
of one or more vertical sashes which also contain horizontal sliding sashes. Sashes are
typically comprised of safety glass or other types of highly durable transparent material.
The maximum allowable sash opening that will ensure that the required face velocity
can be maintained. In most instances the sash design opening or sash design position
will be the same as the fume hood’s maximum possible sash opening. However, if the
laboratory ventilation system was not designed (or cannot be relied upon) to maintain
the required face velocity at a fume hood’s maximum possible sash opening, then a
maximum allowable
sash opening needs to be imposed for safe usage.
A fume hood equipped with a VAV fume hood controller that controls the airflow
through the fume hood to maintain a constant average face velocity regardless of the
size of the fume hood’s Face Opening.
If the fume hood design sash opening or
design sash position is less than the maximum
possible sash opening, a mechanical stop to
limit sash travel should be utilized.
VAV fume hoods normally require that the
laboratory room ventilation (that is, room
supply air, etc.) is also provided by a VAV
system.