teaching Some Trends in Planning Chemical Laboratories, Part 11 by M. G. Mellon Distribution of Utlllties Engineers have used several ways to get utility lines (water, gas, steam, air, oxygen, electricity, etc.) to lahoratories and to get drain lines and exhaust ducts from laboratories. There are a t least three structural provisions. The first of these variations involves a t least one vertical pipe shaft for the utility risers. The service lines take off horizontally a t the several floors, usually suspended from the ceiling, to lead to desired outlets. Similarly, outlets from sinks lead through horizontal lines to the down line in the pipe shaft. In this case exhaust ducts from hoods are not in the relatively small shaft. The risers may he close t o a wall without being enclosed. The second variation, more widely used, involves a series of pipe shafts. Usually there is one for each modular lahoratory unit. Most often they are arranged along a corridor, hut in some cases, they are outside an exterior wall. Figure 1 illustrates corridor installations. The upper part shows a chase for a laboratory 40 f t wide. The lower part shows two variations for lahoratories 10 ft wide, one with a chase for each 10 ft unit, and one with only the exhaust ducts built into the wall. In the latter case the duct opening is directly hehind the baffle plate of the hood. Except for the built-in ducts, each shaft is likely to contain the exhaust flueb) from the adjoining laboratory. The uncommon exterior location of service shafts is illustrated well at the University of California (Berkeley) in Latimer Hall. Figure 2 shows the arrangement for two research lahoratories. The inside dimensions of the shafts are 6 X 6 ft. What is prohahly a unique feature is the balcony between service shafts, with doors opening out from the laboratories. Few other institutions have views t o warrant
Florida
.Service Shaft Corridor
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Illinois Nat. Bur. Stds.
Figure 1. Corridor arrangement ol services.
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Purdue Cornell (Wetherill) (Baker)
Journal of Chemical Education
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Corridor
Figure 2. Exterior service shafts and balconies.
such balconies. The University of Cincinnati has similar exterior shafts as has Colorado State University in its wing containing teaching laboratories. Still another example is the National Environmental Research Center, already mentioned. On each side of the 48 X 134-ft segments there are six utility shafts, 4 X 6 ft. Located 22 f t on center, each one can serve two of the 11 X 20-ft units. The third variation, currently popular, involves a long service shaft or utility core. The common practice is a lengthwise core in the center of the building. At Colorado College, however, this core is a perimeter area formed by a wall set 4 ft inside the exterior wall. There are then no windows. Usually 6 1 2 ft wide, the core can accommodate all risers, electrical bus hars, exhaust ventilation flues, and down drains (toilet, roof, sink). Preferably hoods should he set with their hacks to these cores to avoid horizontal runs .of ducts. Figure 3 shows two ways of placing the walkway in the core area. The center walkway permits close coupling of ducts to hoods hacked up to the service core wall. However, few are so installed. Instead of one lengthwise service core, an uncommon alternative is several crosswise cores. This arrangement is noteworthy in the plan for Duke University. The new
I I Figure 3. Arrangement of flues and walkways
in a service shaft.
huilding at Purdue University uses an adaptation of the Duke plan. The pipe shafts and chases iust discussed are all related to the Gekical distrihution ofutility lines and ventilation ducts. There is still the problem of eettine the service lines t o the points of use, andthe exhaust-ducts~totheir exits. Horizontal runs are made in a number of ways. Frequently the lines are suspended from the ceiling, with takeoffs going up through the floor to equipment. A maze of such pipes is not attractive, unless compared t o some of the so-called a r t ohiects made hv weldine toeether nieces of scrap from the j"nk yard. ~ x i o s e d and duct$ may he hidden with a suspended ceiling. If perforated panels are used, fresh air may he delivered into the plenum chamber so formed to obtain relatively even distrihution of the air. Pipes may be dropped from the ceiling. as mentioned for the IJniversity of Illinois. What amounts to an inverted suspended ceiling is used in the new science huilding a t Earlham College. Two feet above the regular, unsmoothed concrete floor is a second floor. I t consists of a metal framework which supports the floor panels (2 X 4 ft). Then the piping and electrical lines (without conduits) are arranged between the floors. Flexible hose from the sinks, provision for easy change of piping, and economy in installation and maintenance are the sue. gested points of merit. Movable Partnlons
Many buildings in which the working modular distance is 10 f t to 12 ft have partitions at thes;distances to make small rooms for various purposes. T o provide for comhinine two or more of these rooms easily, movable partitions are desirable. Walls of 4-in. concrete blocks are common. Some laboratories, such as those a t the Argonne National Lahoratory and the National Bureau of Standards, have commercially available partitions, such as those made by the Hauserman Company. At the National Bureau of Standards omission (or removal) of the movable metal partitions provides for rooms up td 320 ft long. The new unit a t the University of Illinois is a good example of a late Hauserman installation. Each partition, all a t 10-ft spaces, is formed by a header dropped from the ceiling t o 9 ft. Below this is the movable partition. The header, constructed with detachable bottom and sides, contains horizontal utility lines from the risers in the chase outside the room where they are valved. Connections can he dropped from T's in the header lines to desired locations. No shelves on the movahle partitions for bottles demonstrates that chemists can get along without having in front of them a generous sampling of all the chemicals in the store room. Mounting Supports for Utllny Lines and Experimental Assemblies
Unistrut verticals are now widely used to hold horizontal utility lines, shelf hrackets, cabinets, and experimental assemblies, such as distilling units. They may he either wall-mounted or free-standing. Channel comhination P4004 (4 channels '3hs X 1%in.) is a versatile free-standing form. Fastened a t the top and hottom, it gives a very stable support. One can attach items on all four sides. If wall-mounted, they may he fastened t o every other steel studding set 16 in. on center, or any distance apart on concrete hlocks. If the vertical is in. thick and fastened directly t o the studding, %-in. plaster gives a nearly flush wall. Aluminum T-slot verticals have an advantage in ease of changing shelf hrackets or mounting rods. Set in a 4-in. block wall, a convenient spacing for approximately 32 in. shelves is one vertical each two 16-in. blocks. The mounting is nearly flush. Three-inch channel iron gives a good support for free-standing verticals. With either Unistmt or aluminum verticals. brackets
having a web in the center of the base of the bracket provide for using short shelves that need no fastening and thus facilitate changing or removal. Width of Doors and Corridors
Widths of doors and corridors hardly seem worth mentioning, yet extremes still are to he found. In a recent huilding two lengthwise corridors 14 ft wide are connected by four crosswise corridors, two 14 ft wide and two 21 ft wide. The opposite extreme is a research laboratory with corridors less than 6 ft wide. Very wide corridors are a waste of assignable space except in an area likely to he subject t o traffic congestion, as a t entrances to a lecture room where there is an interchange of successive large sections. Narrow widths will accommodate traffic in a research area. hut there mav he a prohlem getting a large piece of equipment into or o;t of a room. Doors are seldom too wide, hut there are some too narrow. According t o the plans, several large huildings have only 3-ft doors into the lahoratories. Another has a single double door a t an entrance where there is heavy traffic as classes change. The architect should judge need for outside traffic. Advice from the department planner should he heeded for interior doors. Teaching lahoratories should have a t least one 5-ft opening (double doors). This holds also for large research lahora
