[Code of Federal Regulations]
[Title 10, Volume 3]
[Revised as of January 1, 2005]
From the U.S. Government Printing Office via GPO Access
[CITE: 10CFR434.521]

[Page 409-410]
 
                            TITLE 10--ENERGY
 
                    CHAPTER II--DEPARTMENT OF ENERGY
 
PART 434_ENERGY CODE FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH 
RISE RESIDENTIAL BUILDINGS--Table of Contents
 
          Subpart E_Building Energy Cost Compliance Alternative
 
Sec. 434.521  The simulation tool.

    521.1 Annual energy consumption shall be simulated with a multi-
zone, 8760 hours per year building energy model. The model shall account 
for:
    521.1.1 The dynamic heat transfer of the building envelope such as 
solar and internal gains;
    521.1.2 Equipment efficiencies as a function of load and climate;
    521.1.3 Lighting and HVAC system controls and distribution systems 
by simulating the whole building;
    521.1.4 The operating schedule of the building including night 
setback during various times of the year; and
    521.1.5 Energy consumption information at a level necessary to 
determine the Energy Cost Budget and Design Energy Cost through the 
appropriate utility rate schedules.
    521.1.6 While the simulation tool should simulate an entire year on 
an hour by hour basis (8760 hours), programs that approximate this 
dynamic analysis procedure and provide equivalent results are 
acceptable.
    521.1.7 Simulation tools shall be selected for their ability to 
simulate accurately the relevant features of the building in question, 
as shown in the tool's documentation. For example, a single-zone model 
shall not be used to simulate a large, multi-zone building, and a 
steady-state model such as the degree-day method shall not be used to 
simulate buildings when equipment efficiency or performance is 
significantly

[[Page 410]]

affected by the dynamic patterns of weather, solar radiation, and 
occupancy. Relevant energy-related features shall be addressed by a 
model such as daylighting, atriums or sunspaces, night ventilation or 
thermal storage, chilled water storage or heat recovery, active or 
passive solar systems, zoning and controls of heating and cooling 
systems, and ground-coupled buildings. In addition, models shall be 
capable of translating the Design Energy Consumption into energy cost 
using actual utility rate schedules with the coincidental electrical 
demand of a building. Examples of public domain models capable of 
handling such complex building systems and energy cost translations 
available in the United States are DOE--2.1C and BLAST 3.0 and in 
Canada, Energy Systems Analysis Series.
    521.1.8 All simulation tools shall use scientifically justifiable 
documented techniques and procedures for modeling building loads, 
systems, and equipment. The algorithms used in the program shall have 
been verified by comparison with experimental measurements, loads, 
systems, and equipment.