DOE-2 Energy Program
DOE-2 calculates the hourly energy use and energy cost of a commercial or
residential building given information about the building's climate,
construction, operation, utility rate schedule and heating, ventilating, and
air-conditioning (HVAC) equipment.
The DOE-2 program for building energy use analysis provides the building
construction and research communities with an up-to-date, unbiased,
well-documented computer program for building energy analysis. DOE-2 is a
portable FORTRAN program that can be used on a large variety of computers,
including PC's. Using DOE-2, designers can quickly determine the choice of
building parameters which improve energy efficiency while maintaining thermal
comfort. A user can provide a simple or increasingly detailed description of a
building design or alternative design options and obtain an accurate estimate of
the proposed building's energy consumption, interior environmental conditions
and energy operation cost.
What Is DOE-2?
DOE-2 is an up-to-date, unbiased computer program that predicts the
hourly energy use and energy cost of a building given hourly weather
information and a description of the building and its HVAC equipment and
utility rate structure. Using DOE-2, designers can determine the choice
of building parameters that improve energy efficiency while maintaining
thermal comfort and cost-effectiveness. The purpose of DOE-2 is to aid
in the analysis of energy usage in buildings; it is not intended to be
the sole source of information relied upon for the design of buildings:
The judgment and experience of the architect/engineer still remain the
most important elements of building design.
Structure of DOE-2
The figure shows a flowchart of DOE-2. Basically, DOE-2 has one
subprogram for translation of your input (BDL Processor), and four
simulation subprograms (LOADS, SYSTEMS, PLANT and ECON). LOADS, SYSTEMS
and PLANT are executed in sequence, with the output of LOADS becoming
the input of SYSTEMS, etc. The output then becomes the input to ECON.
Each of the simulation subprograms also produces printed reports of the
results of its calculations.
The elements of DOE-2 shown in the figure are as follows:
The Building Description Language (BDL) processor reads the flexibly
formatted input data that you supply and translates it into computer
recognizable form. It also calculates response factors for the transient
heat flow in walls and weighting factors for the thermal response of
The LOADS simulation subprogram calculates the sensible and latent
components of the hourly heating or cooling load for each user-designated
space in the building, assuming that each space is kept at a constant
user-specified temperature. LOADS is responsive to weather and solar
conditions, to schedules of people, lighting and equipment, to infiltration,
to heat transfer through walls, roofs, and windows and to the effect of
building shades on solar radiation.
The SYSTEMS subprogram handles secondary systems; PLANT handles primary
systems. SYSTEMS calculates the performance of air-side equipment (fans,
coils, and ducts); it corrects the constant-temperature loads calculated by
the LOADS subprogram by taking into account outside air requirements, hours
of equipment operation, equipment control strategies, and thermostat set
points. The output of SYSTEMS is air flow and coil loads. PLANT calculates
the behavior of boilers, chillers, cooling towers, storage tanks, etc., in
satisfying the secondary systems heating and cooling coil loads. It takes
into account the part-load characteristics of the primary equipment in order
to calculate the fuel and electrical demands of the building.
The ECONOMICS subprogram calculates the cost of energy. It can also be
used to compare the cost-benefits of different building designs or to
calculate savings for retrofits to an existing building.
The weather data for a location consists of hourly values of outside
dry-bulb temperature, wet-bulb temperature, atmospheric pressure, wind speed
and direction, cloud cover, and (in some cases) solar radiation. Weather
data suitable for use in DOE-2 is produced by running the DOE-2 weather
processor on raw weather files provided by the U.S. National Weather Service
and other organizations.
DOE-2 comes with a library of building input elements, including wall
materials, layered wall constructions, and windows.
Uses for DOE-2
Because of the scope and flexibility of its input, DOE-2 can be used in many
applications, especially those involving design of the building envelope and
HVAC systems, and selection of energy conserving or peak demand reduction
Effect of the thickness, order, type of materials, and orientation of
exterior walls and roofs;
Effect of thermal storage in walls and floors, and in energy storage
tanks coupled to HVAC systems;
Effect of occupant, lighting, and equipment schedules;
Effect of intermittent operation, such as the shutdown of HVAC systems
during the night, on weekends, holidays, or for any hour;
Effect of reduction in minimum outside air requirements and the
scheduled use of outside air for cooling;
Effect of internal and external shading, tinted and reflective glass,
and use of daylighting.
Initial design selection of the basic elements of the building, primary
and secondary HVAC systems, and energy source;
During the design stage, evaluating specific design concepts such as
system zoning, control strategies, and systems selection;
During construction, evaluating contractor proposals for deviations from
the construction plans and specifications;
A base of comparison for monitoring the operation and maintenance of the
finished building and systems;
Analysis of existing buildings for cost-effective retrofits.
Validation of DOE-2
DOE-2 has been validated by comparing its results with thermal and energy use
measurements on actual buildings and with calculations. Detailed information on
some of the DOE-2 program validation efforts may be found in the following
reports (available from the National Technical Information Service, 5285 Port
Royal Road, Springfield, VA 22161):
Comparison of DOE-2 with Measurements in the Pala Test Houses. Lawrence
Berkeley National Laboratory, Report No. LBL-37979, 1995.
DOE-2 Verification Project, Phase 1, Final Report. Los Alamos National
Laboratory, Report No. LA-10649-MS, 1986.
DOE-2 Verification Project, Phase 1, Interim Report. Los Alamos National
Laboratory, Report No. LA-8295-MS, 1981
DOE-2.1E has the following manuals:
The DOE-2.1E Basics Manual is an introduction to DOE-2 for new users.
The DOE-2.1E Supplement to the DOE-2.1A Reference Manual (parts I and
The DOE-2.1E Sample Run Book.
DOE-2 versions are available for most computer platforms and operating systems.
Hardware requirements vary, but generally 32 Mb of RAM and 200 Mb of hard disk
space is required.
Impacts of DOE-2
Following is a summary of the applications and impacts of the DOE-2 building
energy simulation program.
DOE-2 is the most widely-used government-developed program for building
energy analysis in the US and 40+ other countries. It is used to achieve
energy-efficient, cost-effective building designs. Users report an average 22%
reduction in energy use through use of DOE-2. In the U.S., this has led to a
savings of approximately $11B in energy costs through 1998 (an estimate approved
by the U.S. Government Accounting Office).
Building Energy Efficiency Standards: Because it is
scientifically rigorous and open to inspection, DOE-2 has been chosen to
develop state, national, federal, and international building energy
efficiency standards, including:
The ASHRAE-90.1 standard for commercial buildings, which is
based on thousands of DOE-2 analyses for different building types and
climates. The standard is mandatory for new federal buildings, and has
been adopted by many states for non-federal buildings.
The ASHRAE-90.2 standard for residential buildings, which is
based on 10,000 DOE-2 analyses.
The State of California standard for commercial buildings (Title
Standards for other countries, such as Hong Kong, Saudi Arabia,
Kuwait, Singapore, Malaysia, Philippines, Indonesia, Thailand,
Switzerland, Brazil, Canada, Mexico and Australia.
DOE-2 has been used in the design or retrofit of thousands of well-known
Some examples in the U.S. are:
The White House
World Trade Center
Boston City Hall
New York State Capitol
Texas State Capitol
Ronald Reagan Library
U.S. State Department
Bank of Boston
Pacific Museum of Flight
One Magnificent Mile
Examples in other countries are: National Library (France)
New Parliament House (Australia)
Berlin Holocaust Center
Nestle' Headquarters (Switzerland)
U.S. Embassy (Berlin)
DOW Europe (Switzerland)
Renault Technocenter (France)
Citibank Plaza (Hong Kong)
DOE-2 is the basis of books and design guides on
energy-efficient buildings. These include:
Small Office Building Design Handbook
Skylight Design Handbook
Energy and Economics: Strategies for Office Building Design
PWC Daylighting Manual and Microcomputer Spreadsheet.
DOE-2 is the source of algorithms, calculation techniques, and
correlations for many widely-used simplified methods. These
ASEAM-2 simplified energy analysis program
ADM-2 simplified energy analysis program
TrakLoad and LoadShaper simplified energy analysis programs
RESEM program for retrofit analysis
EEDO (Energy Economics of Design Options)
AAMA-SKY program for skylight design
ENVSTD program for ASHRAE Standard 90.1
PEAR program for residential analysis
RESFEN (Residential Fenestration Performance Design Tool)
COMFEN (Commercial Fenestration Performance Design Tool)
The private sector has adapted DOE-2 by adding interfaces that
make the program easier to use. Some examples are these:
Energy Gauge USA
Home Energy Saver (LBNL)
Home Improvement Tool (LBNL)
Perform 2001 PRC-DOE2
DOE-2 has been incorporated in commercial building design software
environments such as COMBINE (European Community) and RIUSKA
DOE-2 results on the energy-efficiency potential of different building
types has been incorporated by Pacific Northwest National Laboratory
in the U.S. Energy Information Administration's National Energy
Modeling System for predicting future energy demand.
DOE-2 is used by professional societies and industry groups for
research, development, and impact analysis. For example, ASHRAE used
DOE-2 for standards development and the Gas Research Institute (GRI)
used DOE-2 to assess the energy economics of, and thereby determine
future R+D and marketing efforts for new gas technologies, including
gas-engine-driven chillers, desiccant cooling systems, direct-fired
absorption cooling, and cogeneration.
Many utility companies use DOE-2 as a key element in their demand-side
management programs to encourage energy-efficiency as an alternative
to building new power plants. For example: Northeast Utilities,
Pacific Gas & Electric and Southern California Edison offer DOE-2
analysis to architects and engineers as an incentive to designing
energy-efficient buildings. The Bonneville Power Authority (BPA) in
its Energy Edge program used DOE-2 to show the practicality of
buildings that use 30% less energy than its existing standard. Pacific
Gas and Electric (PG&E), the largest investor-owned utility in the
U.S., used DOE-2 in its ACT2 (Advanced Customer Technology Test)
project to select advanced energy efficiency retrofit measures in
residential and commercial buildings. Many States use DOE-2 to
determine the potential for energy savings. For example, New York
State used DOE-2 to show that adoption of cost-effective conservation
measures would reduce statewide electricity consumption by 38%.
States and the federal government use DOE-2 to forecast the long-range
cost and energy savings of building energy efficiency programs.
The National Fenestration Council (NFRC) has used DOE-2 to develop
window energy efficiency labels.
Because of its accuracy, DOE-2 is used as a reference standard
program. Two examples of this are:
ASHRAE validated its widely-used simplified energy calculation
method (the TC 4.7 bin method) by comparing its results with
DOE-2. This comparison also led to improvements to the TC 4.7
The California Energy Commission certifies computer programs
for use in Title 24 compliance by requiring that they agree with
DOE-2 to within a certain percentage on a set of test buildings.
DOE-2 is used in 60+ universities in the U.S. for building science
research and for teaching.
DOE-2 has been used by national labs, universities, and industry for
hundreds of studies of products and strategies for energy efficiency
and electric demand limiting. Examples include advanced insulating
materials, evaporative cooling, low-E windows, switchable glazing,
daylighting, desiccant cooling, cogeneration, gas-engine-driven
cooling, cool storage, effect of increased ventilation, sizing of
thermal energy storage systems, gas heat pumps, thermal bridges,
thermal mass, variable exterior solar and IR absorptance, and window
DOE-2 has undergone validation by Los Alamos National Laboratory,
Lawrence Berkeley National laboratory and universities to show that
that the program can accurately predict energy use in real buildings.
Such validation gives users confidence that the DOE-2 results are
reliable for well-described buildings.
DOE-2 was developed by Lawrence Berkeley National Laboratory, Hirsch
& Associates, Consultants Computation Bureau, Los Alamos National
Laboratory, Argonne National Laboratory and University of Paris. Major
support was provided by the U.S. Department of Energy; additional
support was provided by the Gas Research Institute, Pacific Gas &
Electric Company, Southern California Edison Company, Electric Power
Research Institute, California Energy Commission and others.