monitoring data shall be automatically converted to
Hydronic Systems. Systems supplying heated and/or
standard database and spreadsheet format and
chilled water to comfort conditioning systems must also
transmitted to a designated workstation. Energy points
include controls that automatically reset supply water
are those points that are monitored to ensure compliance
temperatures required by temperature changes responding
with ASHRAE Standard 90.1.
to changes in building loads (including return water
temperature) or by outdoor air temperature.
Maintenance Scheduling
Energy Management and Conservation
The BAS shall include programs for control that switch
HVAC control algorithms shall include optimized
pumps and compressors from operating equipment to
start/stop for chillers, boilers, air-handling units and all
stand-by on a scheduled basis. Also, programs that
associated equipment and feed forward controls based on
provide maintenance schedules for equipment in every
predicted weather patterns. Lighting control shall be
building system shall be included, complete with
accomplished by use of separate control equipment,
information on what parts and tools are needed to
which allows BAS monitoring and reporting and control
perform each task.
settings. Optimal start/stop calculates the earliest time
systems can be shut down prior to the end of occupancy
System Design Considerations
hours and the latest time systems can start up in the
BAS's require measurements at key points in the building
morning with the aim of minimizing equipment run time
system to monitor part-load operation and adjust system
without letting space conditions drift outside of the
setpoints to match system capacity to load demands.
comfort setpoints. Weather prediction programs store
Table 5-6 of the previous section outlines the minimum
historic weather data in the processor memory and use
control and monitor points for typical HVAC equipment.
this information to anticipate peaks or part load
Controls cannot correct inadequate source equipment,
conditions. Programs also run economizer cycles and heat
poorly selected components, or mismatched systems.
recovery equipment.
Energy efficiency requires a design that is optimized by
The BAS shall have the capability to allow building staff to
realistic prediction of loads, careful system selection, and
measure energy consumption and monitor performance ,
full control provisions. System ability must include logs of
which is critical to the overall success of the system.
data created by user selectable features. In new buildings
Electrical values, such as V, A, kW, KVAR, KVA, PF, kWh,
and major renovations, the BAS shall have approximately
KVARH, Frequency and Percent THD, shall be measured.
20 percent spare capacity for future expansion. The
See also Chapter 6: Electrical Engineering, for separate
system must provide for stand-alone operation of
metering of power consumption.
subordinate components. The primary operator
workstation shall have a graphical user interface.
Energy management measurements shall be totalized and
Standalone control panels and terminal unit controllers
trended in both instantaneous and time-based numbers
can have text-based user interface panels which are hand-
for chillers, boilers, air-handling units and pumps. Energy
held or fixed.
156 F A C I L I T I E S S T A N D A R D S
FOR THE
PUBLIC
BUILDINGS
SERVICE
Revised March 2005 PBS-P100
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