As the economic downturn lingers, departments across the country look for ways to reduce budgets. Smart facilities, including laboratories, can save space and energy (and therefore money) compared to traditional facilities. One area in which facilities are becoming increasingly smart is user identification. The ability for the facility to identify users helps in the three most paramount issues of forensic design: safety, efficiency, and security. We’ll examine three different technologies which work in conjunction with three different items that are common to forensic facilities—fume hoods, lighting, and evidence security.
Fume hoods are the first line of defense in the safety of users against chemical exposure and work on the principle of containment and directing airflow away from the user. They are also expensive to run. The typical fume hood in the U.S. uses “3.5 times as much energy as a home.”1 Two recent technologies have helped reduce the amount of energy fume hoods use; fume hood occupancy sensors and the newest generation of ductless fume hoods.
In a traditional fume hood, air is drawn through the sash in one direction and at a velocity to assure that any contaminated air within the hood cannot escape. The air runs through the fume hood and is then exhausted out of the building. The air pulled through the hoods is conditioned—we are paying to condition air and then almost immediately exhausting it out of the building. Fume hoods exhaust significantly more air when the sash is open than when the sash is closed. For any number of reasons, users may leave the sash open when the fume hood is not in use. Finding ways to reduce the amount of time fume hood sashes are unnecessarily open will help reduce the energy use of a facility. Keeping the sash closed when a fume hood is not in use is also a good safety practice. One way to keep fume hood sashes closed when not in use is with fume hood occupancy sensors, also called automatic sash operators.
Automatic sash operators identify if there is a user at the hood or not and raises or lowers the sash in accordance with that information. An example of an automatic sash operator is Labconco’s Intelli-Sash. The Intelli-Sash utilizes a passive infrared occupancy sensor which automatically senses the presence of a person and will open the sash accordingly. The cone of sensitivity of the sensor can be adjusted to account for such differences as someone being at the fume hood versus someone simply walking past the fume hood. Reaction time for the auto-open feature is quick and closing times can be adjusted to your preference. This feature also includes built-in safety features, for example the sash will stop short of an obstruction in its path.2
Even with automatic sash operators, a standard fume hood and associated HVAC system will still exhaust air out of the building which increases energy costs. Ductless fume hoods expend far less energy, since they do not exhaust conditioned air out of the building. They too have features which identify use.