Engineering Controls and Laboratory Design Session 4 Laboratory Safety Training.
-
Upload
victor-york -
Category
Documents
-
view
220 -
download
0
Transcript of Engineering Controls and Laboratory Design Session 4 Laboratory Safety Training.
Engineering Controls and Engineering Controls and Laboratory DesignLaboratory Design
Session 4Laboratory Safety Training
2
Types of LaboratoriesTypes of Laboratories
Academic vs. IndustrialResearch vs. InstructionalSimilar functions housed
togeather vs. building for entire departments
Future flexibility, diversity.
3
Engineering and Architectural Engineering and Architectural PrincipalsPrincipals
Laboratory buildings present difficult challenges– Very little assignable space (65%)– Energy hog, conditioned air, elec.
needs, services, fire protection life safety issues,
Architects must balance beauty with safety.Engineers must balance conserving energy
with safety.Both must balance users needs and cost
with safety.
4
Organizations Regulating Organizations Regulating Laboratory DesignLaboratory Design
Southern Building Code (SBC)Building Officials and Code
Administrators (BOCA)National Fire Protection Assoc
(NFPA)Standard Fire Protection Codes
5
Basic life safety design Basic life safety design componentscomponents Labs should be designed to provide at
least one, usually two clear means of egress.
The building should have at least two clearly marked means of egress at opposite ends of the building for occupancies up to 500 persons (3 for 500-1000).
Doors must swing in the direction of the exit travel
6
Basic life safety design Basic life safety design componentscomponentsTravel distance must not exceed 200
ft (with no fire suppression, 250 with).1 hour fire rated corridors, stairwells,Storage not permitted in these areas.Self closures on doors.Areas of refuge. ADA compliance issues ramps.
7
Basic life safety design Basic life safety design componentscomponents
Emergency power for signs, lights, equipment.
Chemical Storage room requirements – Class I Division 2 requirements
(normally contained flammable liquids).
8
Fire Protection SystemsFire Protection Systems
Fire Protection Systems–Sprinkler systems–Co2 systems–Inergen (N2 Ar, Co2)–Dry Chemical systems
9
Fire Detection SystemsFire Detection Systems
Automatic and Manual stations are required.
Networked systems.Visual and audible.Fire extinguishers.
10
Other Issues/EquipmentOther Issues/Equipment
Backflow prevention on the clean water (potable) side. Contamination can occur during pressure differentials of a piece of tubing in a sink under water flush several toilets and the pressure drops on the dirty side causing a back flow of water.
11
Chemical resistant casework, typically epoxy coating.
Flammable storage cabinets.Acid storage cabinets.Glove boxes.Local exhaust ventilation for
equipment, processes.
Other Issues/EquipmentOther Issues/Equipment
12
Other Issues/EquipmentOther Issues/Equipment
Biological safety cabinets– Class I-III (glove boxes) partial to
100% exhaust.Emergency eyewashes and safety
showers.– Must tempered and require no more
than 10 sec to reach.
13
Other Issues/EquipmentOther Issues/Equipment
Compressed gas storage.Vacuum, air, compressor issues.Waste issues.
14
VentilationVentilation
All labs using chemicals require 100% out side air. The number of air changes per hour (ACH) are recommended by various organizations.
Regulated by organizations like ANSI (American National Standards Institute), ASHRAE (American Society Heating Refrigeration, Air Conditioning Engineers), NFPA (National Fire Protection Association), OSHA
15
Ventilation Cont.Ventilation Cont.
Because of the requirement for 100% outside air and the number of exhaust point and exhaust volume mechanical systems are one of the largest costs.
Variable air volume systems were designed to minimize these cost.
Constant air volume hood systems with set backs
16
Types of Hoods Types of Hoods
Constant Air VAVAuxiliary airRecirculated Air (bad bad bad)
17
Constant Air Volume HoodsConstant Air Volume Hoods Known also as bypass hoods Face velocity changes as sash is opened
but total exhaust remains constant. Advantages:
– Simpler to maintain.– Can be manifolded or have individual fans.– With off time set backs can be more efficient
18
Constant Air Volume HoodsConstant Air Volume Hoods
Disadvantages– Can be inefficient in smaller labs
with several hoods.
19
Variable Air Volume HoodsVariable Air Volume Hoods
Maintain a constant face velocity independent of the size of the sash opening
Tracks room pressurization (to keep room negative) to fume hood exhaust.
Manifolded system, redundant fans. Reduces possibility of reentry into
building.
20
Variable Air Volume Hoods Variable Air Volume Hoods Cont.Cont.Potential cost savings by allowing
a reduction of supply air when sash is shut.– Hoods exhaust 1000-1200 cfm– 8-10 ach, at $6-8/cfm of conditioned
air can get very expensive.
21
Variable Air Volume Hoods Variable Air Volume Hoods DisadvantagesDisadvantages
Initial cost high.Many control points to track,
potential for malfunction.Difficulty in maintaining
sophisticated controls.When the system goes down the
entire building is not exhausted.
22
Auxiliary Air HoodsAuxiliary Air Hoods
Advantages– Unconditioned air is deposited into the hood
at the face. Saves on conditioned make-up air.
Disadvantages– Researcher is either cold or hot while
standing at the hood.– Requires a separate supply system.– Difficult to balance, maintain containment.
23
Recirculated Air Fume Recirculated Air Fume HoodsHoodsShould never be used,
recirculates fumes after passing air through a filter.
24
25
26
27
28
Single Hood - Single Hood - Single FanSingle FanCAV SystemCAV System
29
Multiple Hood - Single Multiple Hood - Single Fan CAV SystemFan CAV System
30
Multiple Hood - Multiple FanMultiple Hood - Multiple FanVAV SystemVAV System
31
Minimum hood standardsMinimum hood standards All hoods must be tested to the ANSI//AIHA Z9.5 standard.
Requires a manufacturers test, as installed test and as used test. Minimum face velocity must be be 80-120 fpm, optimum 100 fpm at 18” sash opening.
Flow monitors should be installed on all new hoods with a visual or audible alarm
32
Minimum hood standardsMinimum hood standards
ANSI/ASHRAE 110 , smoke visualization and tracer gas tests are recommended to identify hood performance and containment.
33
Hood installationHood installation
Fume hoods should be placed in the back corner of the room away from turbulence and diffusers.
Not near the means of exit. Away from windows.
34
35
36
37
38
39
40
41
42
43