Version TRNSYS v.17 - Extremely Flexible Graphically Based Software

TRNSYS is mainly used by engineers, architects and energy consultants to design and optimise energy systems (focus on renewables and emerging efficient systems) and to design low energy buildingns (ZEB - Zero Energy Buildings, NZEB - Net Zero Energy Building)

TRNSYS is made up of two parts. The first is an engine (called the kernel) that reads and processes the input file, iteratively solves the system, determines convergence, and plots system variables. The kernel also provides utilities that (among other things) determine thermophysical properties, invert matrices, perform linear regressions, and interpolate external data files.

The second part of TRNSYS is an extensive library of components, each of which models the performance of one part of the system. The standard library includes approximately 150 models ranging from pumps to multizone buildings, wind turbines to electrolyzers, weather data processors to economics routines, and basic HVAC equipment to cutting edge emerging technologies. Models are constructed in such a way that users can modify existing components or write their own, extending the capabilities of the environment.

After 35 years of commercial availability, TRNSYS continues to be a flexible, component-based software package that accommodates the ever-changing needs of both researchers and practitioners in the energy simulation community.

TRNSYS has an extensive cross section of users worldwide that spans from researchers to consultants, engineers to building simulation experts, and students to architects. Because of the wide user-base, the tool's long history, and its inherent flexibility, it is actively being used in many of the following applications:

• Building Simulation (including LEED Energy Modeling)
• Solar Thermal Processes
• Ground Coupled Heat Transfer
• High Temperature Solar Applications
• Geothermal Heat Pump Systems
• Coupled Multizone Thermal/Airflow Modeling
• Optimization
• Energy System Research
• Emerging Technology Assessment
• Power Plants (Biomass, Cogeneration)
• Hydrogen Fuel Cell Systems
• Wind and Photovoltaic Systems
• Data and Simulation Calibration

Despite the fact that the TRNSYS library contains the most common energy systems, the user can easily modify or create new components for technologies not covered in the standard library, as it is open source software and provides a method for adding new modules based on the Fortran source code.

Because of the large number of TRNSYS users worldwide there are nonstandard libraries available that simulate the behavior of other components. There is a library of freely available components whose source code are at the service of the scientific community. There are also libraries of components sold by TRNSYS distributors, from heat pumps and geothermal systems to detailed models of solar collectors, controllers, or swimming pools.