In the Product Focus on Fume Hoods in the July/August 2008 issue of Lab Manager, three industry experts shared some ideas on what you should know before purchasing a fume hood and how to get the most out of one. Here we continue the discussion with answers on matching the hood to the work being done, new developments in the technology, and a few parting thoughts.
How do you match the fume hood type to the work being done?
Trinda Wheeler (Labconco):
The most important question in determining the best fume hood for you is: What chemicals and processes are done inside your fume hood? Some fume hood liners are highly resistant to corrosion, while others may be better suited for processes that only involve non-corrosive reagents. Your fume hood size can be very important if you have equipment that needs to be inside the fume hood. It is very important to contact the manufacturer of any fume hood you are considering to make sure you are choosing the best fume hood for you.
Peter Burke (Flow Sciences):
Study the applications as thoroughly as possible. Does the application involve powders or fumes? Is it highly corrosive or flammable? Does it entail significant space requirements? Are there ADA considerations? Some applications can get better efficiency and containment using a task specific workstation over a traditional fume hood, especially if powders are being used and filtration is required. Systems of this nature allow for better access to the task being performed and enhanced worker comfort. Most applications take place on the laboratory bench; therefore containment options specifically designed for the bench top may be better suited than a fume hood.
Terry Thompson (NuAire):
Do your homework. Examples: Find out if you need personnel protection only or product protection also. If you are working with perchloric acid, you will need an exhaust wash down feature. If you are working with delicate instruments or powders, you may need a constant volume air movement hood, versus a variable air volume hood.
What are some new developments in fume hoods or the technology?
The most exciting thing happening in the fume hood industry is the emergence of High Performance fume hoods. High Performance, or Low Flow, fume hoods incorporate special design features that aid in fume containment, thereby making the fume hood even safer to work in than standard fume hoods. In fact, containment becomes so successful, that a true high performance fume hood can be operated using face velocities of 60 fpm or less. When compared to the 100 fpm that has been used with older designs, high performance fume hoods can save 40% on the energy costs associated with operating a fume hood. This massive energy savings is making high performance fume hoods popular in "green" construction, as they can contribute to many points under the LEED rating system. See www.usgbc.org
for more information on LEED.
Thompson: Energy efficiency is probably the most talked about right now, but also ergonomics is a big thing.
Burke: Energy is currently the biggest concern. Ergonomics and worker safety are a much bigger issue than they used to be. People are also tying specific applications like weighing, robotics, distillation, filling and grinding to specific application enclosures. Safe handling of nano sized materials is an area of great interest. Visibility and viewing areas are increasing, and aesthetics and aerodynamics are constantly evolving.
What types of advances can we look forward to?
Burke: We are always using new materials such as stainless steel, tempered glass, and polypropylene in its task specific workstations. Flow Sciences’enclosures are also energy efficient when compared to a standard fume hood because they require much less conditioned supply air to replace exhaust air.
Thompson: With the safety these products provide, it has been pretty much been a company policy to make sure the hoods are certified yearly. I think eventually the city or state governments will get involved and make this mandatory. I know some states now are making airflow monitors mandatory, where it used to be an option.
Any parting thoughts?
Wheeler: A fume hood is just one part of a whole system. For a bench-top fume hood, you also need a supporting base cabinet, a work surface (preferably one that is designed specifically for the fume hood with a dished work area), ductwork and exhaust blower (usually located remotely, often on the roof). When budgeting for a fume hood, don't forget to count in costs for installing the ductwork and blower, which can sometimes cost as much as the fume hood itself.
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