15 May 2003
CHAPTER 4 APPLICATIONS
GENERAL. The requirements pertaining to eligibility in this section are
usually necessary to comply with the energy consumption levels mandated herein. The
MIXED OCCUPANCIES. In those cases where a facility will have areas
requiring comfort conditions and areas requiring indoor design conditions that exceed
the requirements for comfort (control rooms, electronic rooms, etc.), use separate
cooling system(s) for the areas requiring the more stringent conditions, or use system(s)
that provide the comfort conditions with supplemental system(s) that provide required
conditioning for the applications served. If, however, areas requiring comfort conditions
require no more than 25 percent of the total cooling capacity or comprise no more than
1,000 square feet (100 square meters) of total floor space, the primary air-distribution
system may be controlled to meet the more stringent conditions. Where reheat is
necessary for areas requiring close control, size the reheat capacity so that it is equal to
the total design sensible heat generated within the area served.
ADMINISTRATIVE AREAS. Generally, administrative areas (including those
in facilities that are not otherwise eligible for air conditioning, such as warehouses,
shops, and hangars) will be air conditioned only in locations where the dry bulb
temperature is 80 degrees F (27 degrees C) or higher for over 350 hours per year.
COMPUTER AND ELECTRONIC EQUIPMENT AREAS. Deviate from the
indoor design conditions required for comfort conditioning, including temperature and
humidity limits, only to the extent required to support the computers and electronic
equipment, including communication, surveillance, and research related equipment, to
be housed within the area. If practical, use two or more smaller units to satisfy the
required cooling capacity. This will generally reduce energy consumption at partial
cooling loads and will also increase overall system reliability. Where an under-floor
supply air plenum is used in conjunction with above ceiling return, design the number
and size of outlets in the raised floor to deliver 80 percent of the total supply air. The
remaining 20 percent of the supply air should be routed to the room via cable cutouts in
the raised floor. Specify supply registers suitable for installation in floors on which it is
anticipated that equipment will be moved. Locate ceiling return registers near heat
TOILETS, LOCKERS, AND UTILITY CLOSETS. Maintain these areas at a
negative pressure relative to adjacent areas by exhausting air transferred from these
adjacent areas to the outdoors. Where possible, the heating equipment capacity or
energy consumption will not be increased by these areas.
VESTIBULES. Vestibules may be heated to 50 degrees F (10 degrees C) to
melt tracked-in snow in locations where conditions warrant. Otherwise, vestibules will
not be heated or air conditioned.
ATTICS. Where attics are used in facilities that will be air conditioned, the
attic shall be designed to achieve the maximum natural ventilation.