18 August 1998
b. New HVAC systems may be needed to separate a continuously operating area from an area
requiring night setback capability.
c. VAV boxes installed in air distribution ductwork modulate air flow to conditioned spaces, through
positioning of an air valve or damper, to control space temperature. In addition to air flow modulation,
VAV boxes may include reheat coils and induction fans. Stand-alone VAV boxes are generally equipped
with pneumatic or electronic controllers which are interfaced to pneumatic space thermostats or electronic
space temperature sensors. If the stand-alone VAV box controls are in poor operating condition,
replacement of the controls with box-mounted unitary controllers interfaced to electronic space
temperature sensors may provide cost savings and operational benefits. The unitary controllers would be
networked together and interfaced to a smart field panel, allowing centralized monitoring, alarm reporting,
and setpoint adjustment through the UMCS. The designer will include in the design drawings the location
of each new unitary controller and associated temperature sensor. For projects requiring the replacement
or addition of VAV boxes, it is often less costly to have the unitary controllers furnished by the UMCS
supplier and mounted to the VAV boxes at the VAV box supplier' factory, rather than install the unitary
controllers at the construction site.
17. NEW BUILDING PREPARATION. New buildings which must be prepared for UMCS will be
designed following current guidelines. The guidelines shall be verified for the following requirements:
a. Installation of UMCS sensors, including wiring from these sensors to a data terminal cabinet.
b. Provision of HOA switches at equipment electrical starters for future UMCS start/stop interface
through the auto switch position. HOA switches will be provided with auxiliary contacts for UMCS
c. Provision of auxiliary contacts for monitoring of equipment status and common alarm
contacts from local control panels.