DG 1110.3.120
DESIGN GUIDE: MUSIC AND DRAMA CENTERS
JANUARY 1981
C H A P T E R 3: ENVIRONMENT
On the other hand, many Rooms have inade-
formers undertake some of the most strenuous
quate noise reduction details built into their sys-
sustained exercise in human capability. A battery
terns. As a result, the systems are shut down
of high power lights and motorized devices emit
during performance, causing increasing discom-
still more heat into a carefully sealed enclosure,
fort that must be offset between the acts with
wherein the engineer is called upon to maintain
high load cycling. In comparison, initial discom-
comfort conditions without attracting the notice
fort is preferable.
of the occupants. At the same time, the archi-
tectural design must maintain (and periodically
Music facility peak cooling and power loads will
vary) environmental characteristics that are at
be less exaggerated. Considerable sophistica-
best subjectively defined. The patron who was
tion of control systems is involved, and the
absorbed in the presentation must at some point
acoustic noise control criteria applied to air dis-
return to the everyday world, collect wraps and
tribution and mechanical devices are among the
go home, satisfied.
strictest practicable. Acoustic linings, sound traps
and isolators, and required low velocity at supply
A. MECHANICAL SYSTEM FACTORS
grilles necessitates extensive ductwork and the
treatment of large amounts of outside air.
1. Heat Gain
DOD Construction Criteria recognizes ASHRAE
During performances, mechanical systems are
standards and procedures in most details. How-
devoted to cooling and ventilating. Cooling loads
ever, the latest reference ASHRAE Handbook and
are the product of people, power consumption,
military technical manuals should be checked to
and local climate conditions.
be sure the critical noise control, pressure bal-
Although the major loads are internal, the re-
ances and humidity criteria are correctly identi-
quired properties of building enclosure will have
fied before design begins. Designers should be
bearing on the contribution of external loads.
certain that every relevant factor is pinned down
Insolation (glass gain) will be small, but large
and included in the final load calculation, includ-
surface areas are involved. The acoustic benefits
ing all appliance loads, occupants, orientation of
of massive masonry construction for Music fa-
the building and ventilation requirements.
cilities, in particular, necessitate a concern for
thermal lag contribution to the load at peak eve-
Recommended ventilation at 30CFM per person
ning hours.
includes fresh air at 15CFM per person when no
air conditioning takes place. In mild weather, pre-
Special characteristics associated with Drama
performance cycling of this kind may be suffi-
activity include a proportionately higher contri-
cient, but as heat loads increase, cooling and
bution from extensive lighting equipment and
dehumidifying become necessary. Since the
hoist motors, as well as from strenuous effort
stale air is being filtered, treated, and mixed with
occasioned by dancers and scene handling crews.
fresh air, conditioned air may be supplied at a
Special characteristics for Music activity include
lower rate-25CFM per person-with only 10CFM
lower lighting and effort loads, but typically a
of outside air. This should provide a comfortable
larger total occupancy. Moreover, the duration
8 air changes per hour and a reasonable econ-
of critical tolerances extends beyond perfor-
omy in the cooling cycle.
mance hours in the interest of maintaining con-
stant conditions for musical instruments. This
3. Typical Approaches
includes relative humidity near 50%, which will
Because of the closed nature of performance
incur additional power consumption depending
Rooms, heat generation needs will be relatively
on outdoor conditions.
low. Considering fuel resources nationally, it will
be wise to consider convertible sources-such
2. System Characteristics
as interruptible gas and stored fuel oil combi-
Drama facility systems will encounter high peak
nations-or electricity. Since many Army instal-
cooling loads and high peak power loads, and
lation community cores are relatively compact,
must be able to handle large fresh air changes.
available or proposed central steam generation
Loads peak rapidly as the audience enters and
should be evaluated, recognizing the relatively
the performance begins. The logical tendency to
low carrying load for heating. Cooling is the prin-
start-up systems in advance of curtain time often
cipal demand. Absorption cooling using steam
results in a period of discomfort until actual
supply may be feasible if excess capacity in year-
loads catch up.
round steam generation exists at peak perfor-
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