DOE-2 Overview and Basic Concepts

Background  US public domain programs from 1970s Post Office program; NECAP (NASA energy- cost analysis program); NBSLD (National Bureau of Standards Load Determination) Cal-ERDA (California + U.S. Energy Research & Development Administration) program Department of Energy (DOE) funding  First generation DOE-1.4 program (1978)  Later DOE-2.0A, 2.1A, B, C, D, E come out  Program description

Background  Current versions DOE-2.1E (official), DOE-2.2 & PowerDOE Maintained by the Simulation Research Group of Lawrence Berkeley National Laboratory (LBNL) Funded by U.S. Department of Energy (DOE)  Several PC versions & interfaces, e.g. ADM-DOE2, FTI-DOE, VisualDOE (at a cost) eQUEST (freeware)

Background  In the past, mainly used by researchers DOE-2 is powerful but very complicated Require much input time & detail Need efforts to learn & to master  In recent years, also used by building designers & energy analysts Consider as the reference program in USA Becoming popular internationally (e.g. for developing building energy codes) Often used for performance-based energy codes

Background  Based on transfer function theory & weighting factor method; in FORTRAN language  Program structure Building description language (BDL) processor  Error diagnosis & calculate response factors Simulation subprograms  LOADS – building loads  SYSTEMS – secondary HVAC system  PLANT – primary HVAC system  ECONOMICS – economic analysis

Main Features  Capabilities Energy conservation studies  Building envelope design (materials, construction, etc.)  Internal loads (occupant, lighting, equipment)  HVAC systems & plant Building design studies  Daylighting & ventilation design  Energy & environmental systems  Such as cogeneration, desiccant cooling & ice thermal storage  Economic & life cycle analysis

Main Features  Limitations Cannot model electrical & lift systems Certain constraints on some building systems Inflexible FORTRAN structure Sequential calculation method (L-S-P-E)  Not able to consider heat balance

Simulation Process  DOE-2 input file (BDL instructions) Input files in ASCII text format Commands, subcommands & keywords Basic file structure:  LOADS section  SYSTEMS section  PLANT section  ECONOMICS section (optional) DOE-2 Simulation Engine Input 1 Input 2 Output

Simulation Process  Run periods Normally whole year (8,760 hours) May run on shorter period (say, one month) May carry out simulation for multiple years (if the weather files are available)  Control of simulation process Base case design Design alternatives (done with interface program) Parametric runs & analysis (may be tailored made)

Simulation Process  DOE-2 output reports Standard reports  Verification reports + Summary reports  For loads, systems, plant & economics Hourly reports  Very detailed; for checking by advanced users  Program-specific output Summary graphs and tables Customised reports Errors & diagnostics

Simulation Process  DOE-2 output files & reports Commonly read summary reports:  LS-A (Space Peak Loads Summary)  SS-A & SS-B (System Monthly Loads Summary)  PS-A (Plant Energy Utilization Sumary)  PS-B (Monthly Peak and Total Energy Use)  PS-E (Monthly Energy End Use Summary)  BEPS (Building Energy Performance Summary)

Design Weather Typical Weather Design Load Calculations Peak Design Loads Energy Calculations Equipment Sizes and Plant Capacity Building Energy Consumption

Input Requirements  Input data Site data  Building type, location, geometry, construction  Weather data: design weather, weather files Building data  Surface areas, windows, zoning, room shapes  Building materials, mass, finishes, shades  Operating schedules & profiles  Internal loads, design conditions

Input Requirements  Input data (cont’d) Building systems  HVAC (air side) system type & performance  Lighting & electrical services Building plant and equipment  Performance of refrigeration, boiler & other plants Data for economic analysis  Electricity tariffs/rates, fuel prices  Equipment costs, interest rates

Input Requirements  Model zoning (thermal, not geometric) Should consider thermal loads (e.g. interior- perimeter), occupancy, lighting type and schedule For existing buildings, refer to actual zoning Need to simplify the model  Combine zones with similar load and usage  Intermediate typical floors are modelled as one floor  Combine HVAC systems  Sometimes, use ONE zone to quickly calculate the load

Combine several rooms into one zone

Input Requirements  General rules for zoning One exterior zone per major orientation (4-5 m deep) One internal zone per use schedule One plenum zone (if plenum returns) for each air handler One zone each for special uses Separate ground and top floor zones