Talking Sense about...
Utility Enclosures (Floor Boxes)
Exhibits in trade shows and
other events held in modern exhibit spaces have crucial electrical, mechanical
and communications requirements that the competitive convention facility must
provide. Floor Boxes, also known as utility pockets or floor ports meet these
needs best. They are installed flush with the exhibit hall floor as part a
utility delivery grid. Specific
utilities and their capacities will vary from facility to facility based on the
type of exhibits held. The provision of up-to-date utilities is an absolute
necessity for attracting a wide array of trade shows and exhibitors.
exhibit floor planning assumes a ten by ten foot booth area, usually along both
sides of a ten foot aisle. Aisles are
laid out in two counter directions, which create a module. This module is the
basis for the layout of the floor boxes that in combination with the
under-floor utility pathways form a utility system that can service all of the
exhibit booths on the floor. Therefore a single box can service several modules
without above floor utility lines crossing pedestrian aisles.
boxes are connected by a system raceways or conduit, usually PVC pipe. One pipe
will carry power, while others supply communications, audio/visual, air, and
water. This enables the delivery of
services to all or some of the floor boxes and eliminates above-floor hazards
serious convention center exhibit hall projects have demanded floor boxes that
are built to order. One reason for this
is the rapid rate of change in communications systems; another is the need for
more devices than standardized floor boxes can accommodate. They have been
built as large as a desk, but are usually less than three feet square and less
than 24 inches in depth. Vendors with
accumulated designs, patterns and experience can frequently apply these
resources to avoid the need for a more difficult "dead special"
boxes can be fabricated for any type of floor, the most common being
slab-on-grade. The floor box is really
an assembly of three fundamental components; first the box itself, which is
fabricated from sheet or cast metal, or most preferably, PVC. It can be
equipped with fittings to accommodate any type of raceway or conduit as well as
drains and other types of mechanical fittings.
It may be constructed so that one side of the bottom is lower than the
other to direct any accumulation of fluids away from electrical devices and
connections. Second are device plates,
to which are mounted the various electrical, telecom, A/V, or mechanical
devices. These serve to suspend the
devices near the top of the box, away from dirt and fluids, and to facilitate
access from above. The third component
is an integrated frame and cover assembly.
The function of the frame is to secure the box in place and transfer the
load on the cover to the slab. The cover
may be divided and secured in various ways, and in combination with the frame,
bear such loads as trucks and forklifts.
boxes are divided internally so that services are isolated from one another as
dictated by code. Minimally these
dividers or partitions must separate ‘high voltage’ power services from ‘low
voltage’ services such as communications. The drains are usually located in the
mechanical or wet compartment of the box, but may service the entire box by
using weep holes to allow drainage from any of the compartments. Properly designed, the raceway and conduit
serving the floor boxes may also serve as drainage or relief in case of
inundation by large amounts of water.
or all utilities may be supplied by all or selected floor boxes. Most up-to-date exhibit hall floor boxes
provide for power, data, several modes of communication, audio/visual, water
and compressed air. Exactly which
utilities are available from which box depends on the exhibit hall layout and
the anticipated needs of the exhibitors.
It is not always necessary to supply all services to all boxes.
efficient layout will utilize the floor boxes as elements of a complete utility
distribution system. In most cases
adequate services may be provided throughout an exhibit hall with one or two
floor box configurations. Even though the contents of the box may vary, it is
rarely if ever useful to have more than one basic box dimension and
configuration. It is also prudent that
the device plate be common, even though the device selection may vary. Properly designed, the floor boxes and their
raceway should enable the possibility of cost effective and quick retrofits
should circumstances dictate. The
demands by exhibitors for utility services are growing quite rapidly, and
without proper utilities an exhibit facility can become uncompetitive in a short
amount of time.
How to Do It
the floor box is usually considered a part of the facility’s electrical system,
it will also contain elements of mechanical functions. A custom, or special floor box specification
that is not complete in terms of a precise requirement for a drain fitting, for
example, and cannot be fabricated.
The practice, all too common, of hoping that a fabricator bidding the job will
find the time and have the inclination to provide free engineering that will
actually work correctly is one that never succeeds. The floor box design and
firm specifications should be complete, approved and in the hands of a
fabricator at least eight weeks or more before its time to pour floor slabs.
a practical matter, a frequent scenario is that everyone wants to see cement
mixers pouring concrete, so the first component of the floor box that needs to
be shipped is the box itself. Therefore a facility design in which all the
boxes, lids and frames are the same enables the fabricator to ship sooner, and
supply devices and device plates later. The design, approval and tooling for
cast boxes take eight weeks or so from the time drawings are approved for
fabrication. Specifiers should understand that material costs for the boxes are
a poor source for savings, which seldom if ever offset the added engineering
costs involved with multiple or highly customized configurations. In terms of
basic floor box configurations, less is more.
metal fabricators have a very difficult time with built to order floor boxes,
especially if they have not done the work before. If a fabricator has not done
successful work with load bearing products, or has not got experience in
intricate electrical wiring, they will be learning this rather difficult work
at the expense of the specifier’s client. Collapsed floor boxes with forklifts
sticking out of them are not as amusing to facilities people as they are to
other more casual observers on the scene. Floor box specifications frequently
contain an item like this one:
"The frame and
cover assembly shall meet a minimum load rating of HS-44 as defined by the
American Association of State Highway Officials
(AASHO), which states: For a (highway) truck with a maximum single axle load
of 32,000 pounds and dual pneumatic tires, the maximum load on one pneumatic
tire shall be 8000 pounds with an assumed footprint of 6” x 10”.
The largest, regularly
available forklifts are capable of a lifting capacity of 33,000 pounds, so the
maximum total load on the front axle is 65,250 pounds, 50% of which is about
33,000 pounds. This, regardless of tire size, footprint, or type, is what a
serious convention center floor box may have to withstand.
often elect to provide devices, and in cases where there is substantial experience,
this may be a good approach. Often it is an attempt to save money that fails
when devices do not fit device plates. This sort of problem cannot be remedied
easily as heavy gauge device plates cannot be reworked effectively in the
field. Again, experience counts for a great deal. A “first article test”, in
which the device plate is matched and wired with specific device plates, is
well worth the short time it takes to do.
a PVC box can be a sound recommendation. PVC can be installed anywhere and does
not deteriorate, so there is no need to waste time figuring out what metal the
box should be made from or whether it should be cast or formed. In addition it
is a commodity that is ready from stock.
phrase “or equal” should not be used to describe devices that will have to fit
precisely into 12 gauge steel plates.
the most important thing to bear in mind regarding floor boxes for convention
center exhibit halls is that without them the hall is a large empty,
unproductive space. They are important and their design as a component within a
critical system should be treated as a major priority.
for Ballrooms and Meeting Rooms
the requirements for utilities for these facilities are relatively modest, the
need to deliver utilities without hazardous floor clutter remains. Floor boxes
for this application tend to be smaller and contain less in the way of devices
and utilities. In addition they usually have to be installed under carpet and
be inconspicuous. The trend to use
ballrooms in small facilities for local trade shows and the growing
requirements for communication capabilities mean that some low cost
conventional floor boxes cannot always do the required job well.
facilities are not the same as offices. Floor boxes in Ballrooms and larger
meeting rooms must be able to withstand the weight of furniture laden dollies,
as well as the use of wet powered carpet cleaning systems. Recent proposed
changes in the pertinent UL standard reflect the reality that commercial carpet
cleaning systems have the same ability to deliver water into a floor box as
does a wet mop on a tile floor.
Conventioneer CMB Series
The pre-designed CMB1212, CMB1414 and CMB1818 are the new industry-standards for hotels, casinos and office buildings, providing utilities under carpeted floors.
Conventioneer EXH Series
The pre-designed Coventioneer EXH Series is based upon thirty years of experience producing superior exhibition hall floor boxes. These industry-standard, multi-utility service distribution boxes are leading-edge and feature-rich, providing a near-custom solution at off-the-shelf prices. The Conventioneer EXH Series is specifically designed for exhibition halls without carpeting, and can be installed flush into a poured slab-on-grade or in a deck poke-through.
Conventioneer Custom Series
Our Conventioneer Custom Series are based upon your application specific floor box requirements and our experience. Designed for any application, our custom floor boxes provide high current value to the architect, engineer, contractor, venue owner, and end user.
Telematic ä telescoping floor boxes
Email us at firstname.lastname@example.org
Please contact Maxicom for additional information, Requests for Proposals/Information and technical assistance.
Maxicom 2990 North 11th Street Philadelphia, PA 19133
Tel. 215-225-2200 Fax 215-225-2222