5.4 HVAC Baseline System
The analysis shall be based on actual parameters and
values found in the proposed building design and not
simply on defaults assigned by the simulation program.
Baseline System Requirements
The analysis shall be performed using a simulation
program. The simulation program shall be a computer-
GSA requires the use of the HVAC baseline system
based program for the analysis of energy in buildings.
described below. Any deviation from the GSA defined
Simulation programs must be capable of simulating:
baseline HVAC system, or from the directives described
8,760-hours per year, hourly variations in occupancy,
herein, shall not be permitted unless previously identified
lighting power, miscellaneous equipment power,
in project programming requirements and submitted
thermostat setpoints, and HVAC system operation defined
directly to, and subsequently authorized by, the GSA.
separately for each day of the week and holidays, thermal
The following section describes the HVAC Baseline
mass effects, the number of required HVAC zones, part-
System and sets forth the minimum system requirements
load performance curves for mechanical equipment,
for GSA projects.
capacity and efficiency correction curves for mechanical
equipment, air-side and water-side economizers, and
The baseline HVAC system shall be comprised of the
following systems and components:
Public domain or commercial software shall utilize the
Dedicated Outdoor Air Ventilation Systems
EnergyPlus, DOE-2.1E, or DOE2.2 simulation engines.
Floor-by-Floor Air-Handling Units
Alternative simulation programs, meeting the above
Perimeter and Interior Heating and Cooling Systems
stated requirements, may be used with prior approval of
A detailed description of each of the individual HVAC
components is included in section 5.8 HVAC Components.
The building energy analysis report shall include all input
and output used in the simulation programs, including:
Dedicated Outdoor Air Ventilation Systems. The
established energy goals for the project, detailed
building shall have dedicated 100-percent outdoor air
descriptions of the budget and proposed building models,
ventilation systems (DOAVS) sized to meet both the
actual local utility rates, descriptions of any and all energy
conservation measures, an analysis of results with final
building. These physically secure, vertically zoned systems
conclusions and recommendations.
shall provide tempered dehumidified outdoor air to the
occupied spaces by either of the two following methods
depending on the specific application, the perimeter
heating and cooling system proposed, and building
Use a dedicated 100-percent outdoor air ventilation
distribution system ducted directly to the occupied
HVAC Baseline System
Revised March 2005 PBS-P100