Fume Hood specifications for Chemical Laboratory

Sat Jun 29, 2024

When specifying a fume hood for a chemical laboratory, several factors need to be considered to ensure safety, compliance, and functionality. Here are the key specifications and considerations:

1. Hood Type:

Bench Top Hood: Standard for most laboratories, placed on a benchtop.
Floor-Mounted Hood: For larger equipment and operations, stands on the floor.
Walk-In Hood: For tall apparatus or large equipment, allows entry inside the hood.

2. Size and Dimensions:

Width: Common widths include 4', 5', 6', and 8'.
Height and Depth: Vary depending on the type and application.

3. Face Velocity:

Recommended face velocity is typically 80-120 feet per minute (fpm).
Lower velocities (e.g., 60-80 fpm) for energy conservation and special applications.

4. Construction Materials:

Liner Materials: Options include epoxy-coated steel, stainless steel, polypropylene, fiberglass-reinforced plastic (FRP), and phenolic resin.
Work Surface: Should be chemically resistant, commonly made of epoxy resin, stainless steel, or phenolic resin.

5. Airflow Type:

Constant Air Volume (CAV): Maintains a constant airflow, regardless of sash position.
Variable Air Volume (VAV): Adjusts airflow based on sash position, more energy-efficient.

6. Sash Type:

Vertical Sash: Moves up and down.
Horizontal Sash: Moves sideways.
Combination Sash: Can be moved both vertically and horizontally.

7. Exhaust System:

Ducted: Connected to an external exhaust system, removes fumes outside the building.
Ductless: Uses filters to clean air before recirculating it back into the room, suitable for specific applications and lower hazard chemicals.

8. Lighting:

Typically includes fluorescent or LED lighting.
Should provide adequate illumination for safe and effective work.

9. Safety Features:

Airflow Alarms: Monitor and alert for insufficient airflow.
Sash Position Alarms: Ensure sash is in safe position during use.
Fire Extinguisher Ports: Access ports for fire extinguishers.

10. Compliance and Standards:

Ensure compliance with relevant standards such as ANSI/AIHA Z9.5, OSHA, NFPA, and ASHRAE 110 for performance testing.

11. Additional Features:

Service Fixtures: For gas, air, vacuum, and water.
Electrical Outlets: Adequate number and placement for laboratory equipment.
Storage Cabinets: Under-hood storage for chemicals and apparatus.

12. Installation and Maintenance:

Proper installation by certified professionals.
Regular maintenance and inspection to ensure optimal performance and safety.

Selecting the right fume hood involves assessing the specific needs and hazards of the laboratory environment, ensuring proper installation, and adhering to safety standards.