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In this blog, we're diving deeper into the nuances of designing fume hoods that are truly inclusive to both able-bodied and differently-abled individuals. We understand that there are compliance rules to follow, such as a maximum worktop height of 34”, a minimum 30” wide kneespace, a maximum height of 48” for reaching post-mounted devices, a maximum 29” deep reach for access to a cupsink, and the use of ¼ turn ball valves for plumbing fixtures. However, does meeting these requirements truly make the hood inclusive? While ADA standards provide a strong foundation, we need to go further to create fume hoods that are ergonomic, flexible, and supportive of diverse research needs.

The worktop height dilemma

Let's start with the 34" maximum worktop height. Yes, this accommodates wheelchair users, but what about taller researchers? A lower worktop may be uncomfortable for some, and simply lowering the hood also lowers the sight lines within the hood. How can we make a bench hood that works for wheelchair users, tall researchers, and everyone in between? One solution is to install a hood on a height-adjustable table. Using a hydraulic or spindle drive table allows the entire hood to move with the table at the push of a button. This seems like an instant solution; however, this approach has its drawbacks. Flexible connections will be required. The corrugated nature of flexible ductwork can hinder airflow by increasing static pressure. Movement of the duct can cause wear and detachment, leading to inadequate airflow and loss of containment. Additionally, condensation and chemical accumulation in the ductwork corrugations, or in any ductwork sag may also compromise its integrity.

Mott's Optima^TM fume hood offers a fully stable installation option, featuring an adjustable work surface. In this particular design, only the worktop and lower baffle are adjustable, leaving all other connections securely fixed. This setup guarantees a stable installation, upholding ADA compliance when lowered, and ensuring a safe and ergonomic environment for all users.

Convertible access to storage space

Next, there's the issue of kneespace. In labs that do not share the space with wheelchair users, the 30" minimum requirement is often seen as wasted space for non-disabled users. But what if we rethink this? We could temporarily fill the space with a base cabinet that can be easily moved when needed. Even better, we could design the hood to accommodate different storage needs based on user requirements.

For example, cabinets made for storing acid and flammable materials have specific requirements for venting and stability, which can restrict their mobility. Acid cabinets, for instance, must be vented and therefore are not easily movable. They need to be fixed in place to prevent the vent hose from being moved, worn out, torn, or disconnected. Conversely, flammable cabinets do not need venting. However, most flammable cabinets do not come with casters because in a fire, one caster may burn faster than the others, leading to the cabinet tipping over and spilling its contents. If a flammable cabinet is shortened in height and used with nylon "glides" or leveling feet, it can be positioned and removed from the wheelchair access kneespace without causing damage to the floor. It is important to remember that this process may not be immediate and might involve emptying the cabinet contents if a researcher requires wheelchair access.

Another key consideration is that ADA requirements indicate a 48" maximum height for reaching post-mounted devices, such as plumbing fixtures, electrical outlets, light switches, and alarm interfaces. If there is not enough room on the hood posts, the devices must be moved down onto the base cabinets. This can be uncomfortable for taller users and expensive due to on-site plumbing requirements. The Optima^TM fume hood has all the electrical devices in the moving apron leaving more room on the post for plumbing fixtures. However, when using standard hoods there are a few tricks we can employ to ensure both sitting and standing users can access everything they need. One workaround is to "flip" the arrangement of devices on one side of the hood. Often when we run out of room it’s because there are identical services on both hood posts. But if we flip the order of fixtures from top to bottom on one of the hood posts, it often ensures that each service is within reach for all users.

Another option to keep devices within reach is to incorporate a combination switch and electrical outlet in place of the standard duplex outlet. This method sacrifices one electrical outlet, but an additional duplex outlet could be installed higher on the post to accommodate standing researchers. Additionally, fitting the alarm interface of the hood within the height range can be challenging. Some alarm manufacturers may offer a "repeater" device that can transmit the audible and visual alarm to a remote location. These repeaters can be easily mounted on the base cabinets or the side of the hood, allowing wheelchair users to silence the audible alarm during set up and tear down of experiments. Make sure that only the repeater's audible alarm is turned on, while the primary alarm unit situated outside the accessible zone has its horn deactivated and only shows a red-light signal. This setup allows wheelchair users to easily mute the horn on the repeater, which is conveniently within everyone's reach.

Achieving the 29" reach dimension in the fume hood is comparatively easier. To do so, position the cupsink towards the sidewall (instead of the back of the fume hood) and ensure that the swivel gooseneck is placed in a way that it can still reach the center of the cupsink. Plan for the base cabinetry below to accommodate a cupsink. For smaller 48” hoods, it may be necessary to use a support leg on the opposite side of the hood to ensure that the kneespace meets the 30” minimum clearance dimension.

The ability to go with the flow

While ¼ turn ball valves are essential for individuals who may not have hand mobility or have limited dexterity, that ¼ of a handle turn offers almost no control over the flow rate of the gasses. Needle valves require 5 full handle rotations to fully open, providing researchers with 20 times the flexibility to adjust the service flow for their research. Including both needle valves and ball valves on the hood ensures that all users can utilize the fume hood services effectively.

Seeing red

When it comes to alarms, it is important to consider the needs of the blind and deaf community. A fume hood alarm must include both visual and audible signals to make sure all users are alerted to danger. Historically the visual signal has been quite small and not as evident because many users can clearly hear the horn. To further assist the hearing impaired, New England Lab created the Flux Red^TM alarm light, which floods the entire hood interior with red light.

A fume hood for everybody

So, what does an ideal inclusive fume hood look like? It might include:

• An Optima^TM fume hood for user-customizable worktop heights
• Flipped device placement for easy access from both seated and standing positions
• A mix of needle and ball valves for flow control flexibility
• The Flux Red^TM alarm for enhanced safety for all users
• Base cabinets on glides for flexible storage solutions

By taking these steps, we can create fume hoods that truly embrace the concept of universal design – solutions that are accessible, adaptable, and usable by all. Let's make fume hoods a safe space where every researcher, regardless of their physical abilities, can thrive!

Written by:

Rand Weyler – Director of Client Technical Support – New England Lab

Samantha Robinson – Marketing Coordinator - New England Lab

Ken Crooks – Director of Business Development – Mott Manufacturing