Product Focus: Fume Hoods

The fume hood in your lab might seem ancient, unless you imagine Thomas Edison working in the early 1900s under a fireplace chimney. In the summer, though, Edison’s idea failed to create enough draft as outside temperatures increased.

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Energy Savings, Staff Safety, and an Integrated Approach make up Key Planning Considerations

The fume hood in your lab might seem ancient, unless you imagine Thomas Edison working in the early 1900s under a fireplace chimney. In the summer, though, Edison’s idea failed to create enough draft as outside temperatures increased. So for his warm-weather “fume hood,” Edison worked on a shelf placed outside a window, where he could raise and lower the vertical sash for access and protection as needed. Fortunately, modern fume hoods offer much better performance from safety and efficiency perspectives.

In essence, a fume hood should allow a researcher to work with—but not be exposed to— materials that create toxic fumes or particles. The sash on a fume hood helps to confine the toxic substances inside and it also protects the user from most splashes, for example, as long as the sash is kept as low as possible. Airflow through a hood also plays a fundamental role in confining any fumes.

In many labs, the same fume hoods stay in service for decades, serving generations of students and researchers. Consequently, some users simply want fume hoods that look and function like they fit in a modern lab. For example, Jacquie Richardson, Ph.D., director of the organic chemistry teaching labs at the University of Colorado at Boulder, says, “Our student fume hoods are pretty behind the times. The main upgrade I’d like to see is getting something that’s up to date.”

Meeting modern fume-hood standards requires a range of features. The hood must provide high performance in terms of safety, energy efficiency, and durability

Energy-efficient exhaust

“Energy savings is one of the biggest trends or points of concern in fume hoods,” says David Campbell, vice president of sales at HEMCO (Independence, MO). “A fume hood has to exhaust air to maintain a safe working environment for the user. So when it’s exhausting air to the outside, that’s an energy hog for balancing air conditioning and heating in labs.”

Despite this energy issue, lots of users keep hoods open. “You can walk into virtually any lab with a hood and find a sash wide open and no one using the hood,” says Campbell. Consequently, many fume hoods come with energysaving features. For example, the opening height of the sash can be limited. A hood can even include a sensor that closes the hood partway when the user walks away. “The key is keeping the sash lowered,” says Campbell. “The opening height determines how much air is necessary to maintain a velocity that needs to be met for the user’s requirements.”

Users can also add night setback devices. These reduce a hood’s energy consumption during off hours by cutting back the airflow rate when no one is likely to be using the hood.

Resisting rust and corrosion

Energy makes up just one element in keeping a fume hood green. A second factor comes from making a long-lasting piece of lab equipment. “If a fume hood rusts out in a short period of time, that’s not green,” says Campbell.

To help a hood stand up to chemicals and corrosion, different companies take various approaches. For example, Campbell and his colleagues at HEMCO use composite resin surfaces. He adds, “We mold the pieces together seamlessly with the same material rather than using screws.”

Other materials also battle corrosion. NuAire (Plymouth, MN), for example, builds fume hoods from polypropylene. “This is a real niche market,” says Terry Thompson, polypro sales manager at NuAire. “You go with it over steel or fiberglass for really corrosive environments … Polypropylene won’t rust and it can stand up to virtually any chemical out there.”

Other materials also battle corrosion. NuAire (Plymouth, MN), for example, builds fume hoods from polypropylene. “This is a real niche market,” says Terry Thompson, polypro sales manager at NuAire. “You go with it over steel or fiberglass for really corrosive environments … Polypropylene won’t rust and it can stand up to virtually any chemical out there.”

Location, location, location

In real estate, location always plays a key role in success— making up the top three factors, according to the industry mantra. Likewise, location fundamentally impacts the performance of a fume hood.

To understand the finer points of designing and planning a laboratory, researchers can turn to Rx3D, headquartered in New York City. The experts at Rx3D design and plan clinical and basic research laboratories for a wide range of applications, including animal biosafety, the pharmaceutical industry, and much more.

“Fume hoods are a key component in the design of many clinical and research labs,” says William N. Bernstein, AIA, president of Rx3D.

“If a fume hood is in the lab’s main traffic flow, the air currents generated by that traffic may compromise the unidirectional airflow from the room into the fume hood and then from the fume hood to the exterior,” says Bernstein. “By locating the fume hood out of this main traffic, we can help prevent the air within the fume hood from migrating back into the room.” Even if people walking through the lab go too close to the fume hood, that can affect the flow. To prevent this problem, Bernstein suggests putting the fume hood back in a corner of the lab.

Also, a lab’s fume hoods should be considered early in the design process. “It’s an integral part of the overall project design and construction,” says Bernstein. “The fume hoods should be part of the contractor’s work, not considered as equipment that’s furnished separately [and they] should be purchased and installed by the contractor.”

Like others interviewed here, Bernstein noted the trend of reducing the energy used by fume hoods. Although high-tech solutions exist, lab designers should also consider simpler solutions for energy efficiency. For example, Bernstein says, “The easiest way to reduce fume-hood energy is to have less of them.”

Regardless of the energy-reducing approach selected, anyone can surpass Edison’s fireplacechimney hood for efficiency. Moreover, today’s fume hoods also consist of longer-lasting materials. Consequently, a fume hood installed today could perform effectively for years to come. This proves especially true for properly placed fume hoods that are installed correctly.

For additional resources on FUME HOODS, including useful articles and a list of manufacturers, visit www.labmanager.com/fume-hoods  

Categories: Product Focus

Published In

Appifying the Laboratory Magazine Issue Cover
Appifying the Laboratory

Published: May 5, 2012

Cover Story

'Appifying' the Laboratory

In recent years, research labs have been a notable beneficiary as a variety of highly functional and specialized apps have gained the acceptance and even gratitude of a broad spectrum of laboratory managers, research scientists and bench technologists.