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TRNSYS

TRNSYS logo.

An energy simulation program whose modular system approach makes it one of the most flexible tools available. TRNSYS (TRaNsient SYstem Simulation Program) includes a graphical interface, a simulation engine, and a library of components that range from various building models to standard HVAC equipment to renewable energy and emerging technologies. TRNSYS also includes a method for creating new components that do not exist in the standard package. This simulation package has been used for more than 30 years for HVAC analysis and sizing, multizone airflow analyses, electric power simulation, solar design, building thermal performance, analysis of control schemes, etc. Screen Shots

Keywords

energy simulation, load calculation, building performance, simulation, research, energy performance, renewable energy, emerging technology

Validation/Testing

TRNSYS is primarily an equation solving program based on standard numerical techniques. However, validation does become important for the individual components in TRNSYS. See the TRNSYS web site for validation articles related to TRNSYS or its components.

Expertise Required

None to use standard package; FORTRAN knowledge helpful for developing new components.

Users

Over 500.

Audience

Engineers, researchers, consulting firms, architects.

Input

The TRNSYS input file, including building input description, characteristics of system components and manner in which components are interconnected, and separate weather data (supplied with program) are all ASCII files. All input files can be generated by using a graphical user interface, known as the Simulation Studio.

Output

Basic output format is ASCII. The data included in those files can be life cycle costs; monthly summaries; annual results; histograms; plotting of desired variables (by time unit). It is also possible toplot variables online (as the simulation progresses).

Computer Platform

Windows 95 or higher (98, NT, 2000, ME etc.) for TRNSYS interface programs. (Distributed source code will compile and run on any Fortran platform).

Programming Language

FORTRAN (although unnecessary for the use of standard components). It is also possible to write components in C++.

Strengths

Due to its modular approach, TRNSYS is extremely flexible for modeling a variety of energy systems in differing levels of complexity. Supplied source code and documentation provide an easy method for users to modify or add components not in the standard library; extensive documentation on component routines, including explanation, background, typical uses and governing equations; supplied time step, starting and stopping times allowing choice of modeling periods. The TRNSYS program includes a graphical interface to drag-and-drop components for creating input files (Simulation Studio), a utility for easily creating a building input file (TRNBuild), and a program for building TRNSYS-based applications for distribution to non-users (TRNEdit). Web-based library of additional components and frequent downloadable updates are also available to users. Extensive libraries of non standard components for TRNSYS are available commercially from TRNSYS distributors. TRNSYS also interfaces with various other simulation packages such as COMIS, CONTAM, EES, Excel, FLUENT, GenOpt and MATLAB.

Weaknesses

No assumptions about the building or system are made (although default information is provided) so the user must have detailed information about the building and system and enter this information into the TRNSYS interface.

Contact

Company:

Solar Energy Laboratory

Address:

University of Wisconsin
1500 Engineering Drive
Madison, Wisconsin 53706
United States

Telephone:

(608) 263-1589

Facsimile:

(608) 262-8464

E-mail:

trnsys@sel.me.wisc.edu

Website:

http://sel.me.wisc.edu/trnsys

Availability

Version 16, Commercial -- $4200, Educational -- $2100. Free demonstration version and information available from technical contact. International distributors are located in Belgium, China, France, Germany, India, Japan, Republic of Korea, Spain, Sweden, Tunisia and the USA.

Related Web Sites:
Solar Energy Laboratory at the University of Wisconsin
Thermal Energy Systems Specialists - United States TRNSYS distributor and content developers
CSTB - French distributor and developer of the Simulation Studio (graphical front end to TRNSYS)
SERC - Swedish distributor.
Transsolar - German Distributor and source of TRNBUILD graphical building description processor
University of Liege - Belgium Distributor
AIGUASOL - Spanish distributor
Imagic Design Co- Japanese distributor
ATES- Korean distributor
SESI- Indian distributor
AES- Tunisian distributor
CABR- Chinese distributor

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