Thanks to a variety of technological improvements, fume hood accessories have had a greater impact in recent years, either as add-ons or standard equipment.

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AirClean Systems' Independence ductless fume hood includes many of the accessories common to modern fume hoods, including air velocity meters and electrical outlets, and a few that are specific to AirClean, including an on-board chemical reference database and a gas detection sensor suite.

After struggling through much of the past 10 years, the fume hood industry has taken a turn for the better. Late in 2011, consultancy firm IBISWorld released a study of the United States laboratory fume hoods manufacturing industry that showed average annualized revenue increases of 3.5% through 2016, to $748.1 million. In 2012 alone, strong growth of 6% is predicted.

The reasons for the surge aren’t entirely clear, but it is probably due to a combination of factors. Expanded corporate R&D budgets and a rise in laboratory construction and equipment orders are perhaps reasons. But a variety of new fume hood technologies may also be helping.

Two trends transforming the industry, at least domestically, are the arrival of ductless fume hoods, which use activated carbon filters to remove harmful contaminants, and significant improvements in controlling the energy usage of more traditional ducted flow fume hoods.

The $600 million industry looks poised to grow further, and part of that growth will depend on technologies that help users make the most out of both ducted and ductless technologies. Add-ons, from work surfaces to networked control devices, are part of the effort, and fume hood makers have spent considerable effort in developing the side technologies that complement the core.

Fume hood accessories and their role
The problem with trying to assess the fume hood accessories market is that fume hoods differ significantly from model to model. While the basic air flow technology is the same for each company, the modular nature of the product means that custom convenience factors abound.

According to Paul Chambre, CEO, Air Science USA, Fort Myers, Fla., fume hood accessories are part and parcel to the fume hood type. This is especially true at fume hood companies like Air Science, which manufactures a wide variety of both traditional and ductless hoods.

The EDU line is a good example of Air Science's approach. This demonstration ductless hood is built to provide the proper 100 cfm protection level, but also be highly visible, flexible, and mobile. The cabinet has windows on the sides, and is supplied with the most elemental of accessories: caster wheels to allow movement around the laboratory.

Aside from electronic controls and displays such as switches for the blower, a low-air flow alarm or air velometer is a notable accessory that offers uncomplicated air flow feedback in the field of vision of the user. Other mandatory accessories include an internal fluorescent lamp, petcock and water faucet controls, duplex electrical outlet, and a manual speed controller.

Options are a gas petcock, gooseneck water faucet, an integrated polypropylene cup sink, and a polypropylene work surface. Gas supply needs will depend on the type of research being done, but the filtration system, which is based on Multiplex filters and an electrostatic pre-filter, is the same for each EDU fume hood.


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Fume hood accessories aren't always hardware. Air quality expert Aircuity recently introduced a new set of software tools, Advisor Services, that works with its OptiNet sensor technology to help fume hood operators achieve better hood control.

All of these accessories have a long precedence in the fume hood industry, but technological changes are taking place that allow fume hood manufacturers to give more control over the hood's operation. The EDU Series' Basic control panel, for example, is exactly as described: an on/off switch and a low-air flow alarm. As the user’s needs grow, so do the capabilities. The Advanced control panel includes an on/off switch, low-air flow alarm, and an hour meter to aid in determining available filter life. An electronic Filter Saturation Alarm (FSA) is available with the optional Advanced control panel. In addition to all the features of the Advanced control panel, the FSA adds an electronic gas sensor and emits audio and visual alerts when the main filter needs to be changed.

Finally, the optional Monitair microprocessor LCD controller monitors and displays cabinet operating parameters, air flow, containment, and filter condition. It also emits audio and visual alerts if conditions become unsafe.

Digital monitoring, once considered an accessory, is now built in to many hoods and presented as an power-user option for both ducted and ductless hoods. At Mystaire Misonix, Creedmore, N.C., for example, the Advance Filter Monitoring System represents a higher specification level hood. In addition to digital display of air flow velocity, the system supplies audible and visual alarms for low air flow and hydrocarbon breakthrough, filter saturation alarms, a sensor that adjusts blower speed to maintain air velocity, and time tracking of filter use. It also reports the filter type and holds a safety filter to prevent chemical breakthrough even after main filters are completely saturated.

According to Olga Nelson, operations manager at Esco Technologies, Hatboro, Pa., stands and electrical outlets are the most popular accessories requested by customers. Stands are common convenience items for fume hood operators, and the demand for electricity sources may indicate the rising use of meters, gauges, and other electrical equipment inside the hood.

Like Mystaire and Air Science, Esco's fume hoods often include the most popular accessories as part of various stages of fume hood specification. All of the Frontier Acela ducted laboratory hoods, for example, include a Sentinel-XL Airflow Alarm Kit, distillation grids, drip-cups, and work tops. These features can be optional on other types of hoods.

Another standard accessory on the Acela hood are Enhanz service fixtures, which are pre-plumbed remote control service fixtures that can supply water, gas, vacuum, nitrogen, oxygen, compressed air, or argon. Up to eight service fixtures per fume hood can be supplied.

Optional accessories include an electrical safety kit that protects laboratory equipment during a sudden fluctuation of current. A ventilation kit is available that utilizes the hood exhaust system, and filler panels are a required option for installation of a continuous row of hoods.

Going ductless
Several years ago, AirClean Systems, Raleigh, N.C., introduced one of the most advanced ductless fume hoods to hit the U.S. market. Offering a Silconazyne bonded filtration system and an advanced chemical database and reference library system onboard, AirClean offered a glimpse of a "smart" fume hood. "One thing we've already provided on our hoods is a more advanced method of air flow control. Through digital monitoring of the speed of the air flow to the hood we can automatically control the blower to maintain correct velocity," says Brandon Howell, marketing manager at AirClean. "It's not a dial or a guessing game."

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Controlling or keeping tabs on fume hood air velocity doesn't have to be complicated. A common accessory for fume hoods like Air Science's EDU line of ductless hoods is an analog velometer than can be placed in front of the user’s face to help guarantee safe working conditions at all times.

AirClean has since further improved the unit, adding wireless control and monitoring capability. But not all users need this information and added cost. Its newest line of ductless fume hoods, the Patriot, strips away some of the more advanced features on the Independence, such as the chemical database and reference library. Some features from the more expensive line may end up becoming options on Patriot, says Howell.

Another accessory that appears on the Independence fume hood line is a photo ionization detector (PID) mounted in the fume hood frame itself. The PID sensor offers a much higher chemical sensitivity than a conventional metal-oxide sensor, says Howell, and is used in connection with chemical database and reference library to permit exact monitoring and readout of gas levels in parts per million.

The gas detection array also includes the aforementioned metal-oxide array, which is useful because it is sensitive to a range of hydrocarbons and when used in conjunction with the chemical database, it can warn of filter failure. Finally, an acid array monitors airstream pH, and a sampling port built into the front of the Independence accommodates colorimetric gas sampling tubes.

As with all ductless fume hoods, the most visible accessory is the filtration itself. The bonded matrix filters used by AirClean, and for that matter by Erlab and the other ductless hood manufacturers, is considered a standard consumable. Each company offers its own specific filter technology, but variations in filters are starting to appear to accommodate different usage patterns.

Karl Aveard, vice president of GreenFumeHood USA, Rowley, Mass., is focused on extending the use of ductless hoods in the U.S. market. Erlab Inc., a fume hood manufacturer based in France, has expanded its market to the United States and Asia in recent years, and GreenFumeHood technology has begun to appear in more laboratories, both academic and corporate.

Like AirClean, GreenFumeHood has been capitalizing on the modular, self-contained nature of ductless fume hoods to offer better control over its use. In each new fume hood, a software product called gGuard monitors the internal workings of the hood, delivering status updates on filter condition, filter identification, face velocity, sash position, blower motor speed, filter saturation level, and 21 other metrics. Any network computer equipped with the software can monitor and record the fume hood's activity.

Aveard reports that Erlab has also gone a step further by networking an entire ductless fume hood installation to a single computer.

"This is an aid to industrial hygiene professionals and environmental and health services people on particular academic campuses," says Aveard. "They network the hoods, assign an IP address, and the hood becomes a computer in a network. They can monitor activities like sash position."

Cross-pollination of technologies
Fume hood manufacturers aren't the only resource for fume hood accessories. Newton, Mass.-based Aircuity builds on the growing desire for laboratory owners to have greater control over their energy usage by controlling air handling. Specializing in indoor air quality, Aircuity can optimize ventilation with its OptiNet system.

Acting like a data network, OptiNet captures air samples from specific rooms or from air supply ducts, routing them to a centralized suite of sensors. For laboratories using many fume hoods, the single set of high-quality sensors may be more cost effective and ultimately more accurate than a series of sensors positioned at the fume hood itself. Analysis by this central sensor set allows the building management system to adjust ventilation controls on the fly.

Aircuity has recently introduced a new set of software tools, Advisor Services, that help fume hood operators achieve better hood control from the OptiNet system. Advisor Services consists of four components: dashboards, summary reports, smart notifications, and graphing and exporting. There are two components within the dashboard tool that directly relate to fume hoods.

"The first is the sash monitoring graph, which looks at fume hood flow, sash position, and fume hood occupancy and provides graphical representation of sash position both when it is occupied and unoccupied, so sustainability professionals can find out what percentage of the time fume hoods are open," says Callahan.

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Released in April 2012, Mystaire Misonix's latest Aura ductless chemical fume hoods adds more user control in the form of a microprocessor-equipped safety monitor, EverSafe II, which can automatically adjust face velocity to the user’s preset value.

The other chart shows excess fume hood flow. Users can consult this chart to find out how many cubic feet per minute above minimum each fume hood has produced.

From battlefield to laboratory
Software is not the only industry to have an impact on the fume hood accessories market. At GreenFumeHood, one of the only optional accessories offered for its hoods is Fire Foe. This fire suppression device is contained within compact tubes that can be mounted to a wall or to the cabinet of a fume hood.

Made by QuickFire USA LLC, Fort Wayne, Ind., the tubes use heat-sensitive nylon tubing together with a sealing system to both contain and release an Envirogel-extinguishing agent. The agent is a blend of liquefied extinguishing gases combined with a small percentage of micro-ground dry powder, which is held in the container as a gel. The material was developed as the result of the Iraq war.

"Terrorists were throwing firebombs under the rubber tires of the APVs. The rubber would burn away, costing soldiers' lives," says Aveard.

The material was developed to be placed in the wheel wells of the vehicles, and would react when temperatures rose. The Fire Foe tubes themselves activate at 79.4 C; at 157.8 C the activation is instantaneous. The invention helped greatly to protect troops in the event fires, says Aveard, particularly those of a chemical nature. Because the agent release is activated by changes in the internal pressure and tube structure itself, there is no need for expensive external sensor systems or power supplies.