Purchasing Guide: Fume Hoods

Fume hoods are an integral part of the lab. These ventilated enclosures enable laboratory personnel to safely work with materials that produce hazardous fumes or volatile vapors. Selecting a fume hood that is the right fit for your work is important, and there are many different ducted and ductless designs to choose from. Ducted units connect to your facility’s ductwork to direct fumes outside, while ductless units use filters to cycle clean air back into the laboratory. Traditionally, fume hoods consume large amounts of energy, but many newer units are designed with energy efficiency in mind, which reduces operating costs while providing the necessary protection. For a list of fume hood manufacturers, see our online directory: LabManager.com/fume-hood-manufacturers

7 Questions to Ask When Buying a Fume Hood:

What substances will you be working with inside of the hood?
Is a ducted or ductless hood best suited to your needs and laboratory space?
Where will you place the fume hood in your lab? Some considerations to make include workflows, access to external exhaust systems, and competing air patterns.
What size fume hood will best suit your needs? Be sure to consider what equipment may need to be enclosed in the hood.
What service fixtures or accessories such as airflow monitors, electrical outlets, water, or gas fixtures are required inside of the hood?
Are base cabinets for acids, solvents, flammable substances, or non-chemical storage required?
Do you need safety or energy monitoring?

Determining Fume Hood Effectiveness

The effectiveness of a fume hood hinges on maintaining an appropriate face velocity. Too slow a velocity risks exposure, while too fast a velocity causes turbulence and contaminant escape. Thus, measuring worker exposure during actual use yields the most accurate assessment of hood performance and optimal airflow.

Ducted vs Ductless Fume Hoods

While ductless fume hoods come with a host of benefits, there are some applications that ductless hoods are not suited for, such as handling organophosphorus compounds, open acid digestion, and handling hydrogen cyanide. Ensure that ductless hoods are appropriate for your applications before investing in one.