"The application of certain specifications and different configurations can affect not only the pedagogy of the lab but also the safety aspects," says Sean Towne, a principal architect at Research Facilities Design (RFD) in San Diego.

General chemistry, for example, can be approached a number of ways. A four-module design, occupying about 1,250 sf for 24 students, incorporates three traditional island of benches for eight students each, which is a very efficient use of space, says Towne. These benches sometimes house computers along with the sinks and lab instruments.

Another approach is to cluster students in smaller groups of four students each at six island benches. This allows more circulation around the lab, but it is a less efficient use of space, requiring about 1,500 to 1,600 sf for the same number of students.

A third style in general chemistry is to concentrate the fume hoods, piped services, and sinks around the perimeter, leaving the center of the lab available for lower-cost tables and classroom-style learning. The lab can do double duty for classroom functions, as well as the wet chemistry lab. This set-up also can serve about 24 students in 1,250 to 1,600 sf, depending on hood density.

The trend in general chemistry is toward greater use of fume hoods because of the more restrictive way materials are being classified now.

"Some institutions are committing to the use of the fume hood as the primary work station in general chemistry and organic chemistry labs, and even providing additional individual ventilated stations at the work benches," says Towne.

In organic chemistry labs, the fume hood is the primary work station for students. At the University of San Diego, for example, fume hoods ring the room, and the lab contains zones for pre-lab or lecture and instrument benches.

"This allows a place where a lecture or extended pre-lab can occur within the lab, away from some of the noise of the fume hoods, and away from the materials that may be housed in the hoods," explains Towne.

That traditional layout often does not leave any wall space for windows. At Agnes Scott College in Decatur, Ga., the fume hoods form peninsulas in the lab, letting natural light into the room. The fume hoods themselves are sided in glass to allow faculty to monitor what the students are doing, which provides an added measure of safety in the lab.

Fixed-bench biology labs for microbiology and cell/molecular biology courses require a lot of piped services and utilities, with anatomy and physiology labs requiring special ventilation in some cases. Backdraft ventilation, for example, is effective when directly adjacent to benchtop samples, but it loses its effectiveness at one to two feet from the exhaust grille.

"Generally the specimens are trayed and backed up to these devices," says Towne. "The air drops down through the bench and is either ducted back up an umbilical or, in certain configurations, ducted down through the floor."

Another approach for anatomy is to super-ventilate the lab. The system typically is set to 10 air changes per hour, then increased to about 15 air changes per hour when students are doing dissections. The increased air exchange can be noisy, but there is little "lecturing" going on at the same time as the dissections.

"It is a delicate balance between the right CFM for capture and too much, which creates noise," says Towne.

Many biology labs today are outfitted with movable tables for courses such as Introductory Biology, Botany, and Ecology. These labs can make use of movable tables to facilitate changes in configuration for different courses or a range of activities. Power and data can be provided to the movable tables by means of ceiling drops or floor boxes located to support alternative table arrangements. Tables can be arranged in an "eyes forward" lecture configuration with rows of tables facing the teaching wall. Alternatively, the room can be configured for laboratory activities with islands of paired tables for individual or group work. Another option relocates the tables to be "docked" in a peninsula configuration for access to piped services at the fixed perimeter benches or to open up the center of the room for other activities.

Physics labs are also typically outfitted with movable tables, which make it possible to set up separate zones for lecturing and lab work. The lab can contain very simple moveable tables, each with its own computer CPU with power and data lines fed through the floor. Physics labs can contain overhead services as well as support points to hang pendulum devices, bowling balls, bicycle wheels, and other items for large demonstrations.

L.W.