TRNSYS
Simulation & CAE software
- Features
- Ease of use
- Ease of management
- Quality of support
- Affordability
- Market presence
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$2,620 one-time perpetual license
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What is TRNSYS
TRNSYS is a transient system simulation environment used to model the time-dependent behavior of energy systems, with a strong focus on building energy, HVAC, solar thermal, and related thermal/renewable systems. It is used by engineers and researchers to assemble component-based system models, run annual or sub-hourly simulations, and evaluate control strategies and performance. The platform combines a simulation engine with a modular library of component “Types” and supports extending models through custom components and external tool coupling.
Component-based transient modeling
TRNSYS models systems by connecting reusable component modules, which fits HVAC plants, solar thermal loops, storage, and controls. Its time-step simulation approach supports transient effects and long-run (e.g., annual) performance studies. This makes it well-suited to system-level energy analysis where interactions between subsystems matter.
Extensible via custom components
The software supports adding or modifying component models (Types), enabling organizations to implement proprietary equipment models or research-grade algorithms. It also supports integrations and co-simulation workflows, which helps when users need to link specialized calculations or external programs. This extensibility can reduce dependence on a single built-in library when modeling uncommon systems.
Established in energy simulation
TRNSYS is widely referenced in academic and engineering contexts for building and renewable energy system simulation. Its long-standing ecosystem includes third-party libraries and example models that can accelerate common energy-system studies. For teams focused on thermal/energy domains, it provides domain-specific constructs that general numerical computing tools often require users to build from scratch.
Steep learning curve
Building correct models requires understanding the component library, parameterization, and numerical/time-step settings. Debugging can be non-trivial because issues may arise from component interactions, solver settings, or data flow between modules. New users often need training and validated reference models to become productive.
Not a general-purpose CAE suite
TRNSYS focuses on system-level transient simulation rather than broad mechanical CAD/CAE workflows such as 3D geometry-centric design, meshing, and multiphysics finite-element analysis. Users needing detailed structural, CFD, or geometry-driven simulation typically rely on separate tools and then couple results at a higher level. This can add integration effort for multidisciplinary programs.
Licensing and ecosystem fragmentation
Capabilities may depend on optional libraries, third-party components, or specific integrations, which can complicate procurement and reproducibility across teams. Model portability can be affected when projects rely on non-standard Types or external couplings. Compared with some modern engineering platforms, collaboration features and versioning practices often require additional process/tooling outside the core product.
Plan & Pricing
TRNSYS 18 — Main package (one-time perpetual license)
| Plan | Price | Key features & notes |
|---|---|---|
| Commercial — Single-user | $5,160 (one-time perpetual) | Simulation Studio, TRNEdit, TRNBuild, TypeStudio, FORTRAN source for components, electronic manuals, technical support for as long as you own TRNSYS, free v18 maintenance releases, 2-month access to TRNSYS Academy. |
| Commercial — 5-user | $8,680 (one-time perpetual) | Same inclusions as single-user; node-locked or floating license options available via distributor. |
| Commercial — 10-user | $10,210 (one-time perpetual) | Volume seat tier. |
| Commercial — 20-user | $11,680 (one-time perpetual) | Volume seat tier. |
| Commercial — 30-user | $12,740 (one-time perpetual) | Volume seat tier. |
| Commercial — 40-user | $13,260 (one-time perpetual) | Volume seat tier. |
| Commercial — 50-user | $13,790 (one-time perpetual) | Volume seat tier. |
| Educational — 10-user | $2,620 (one-time perpetual) | Educational discount available to qualifying degree-granting institutions (note: TRNSYS educational pricing starts at 10-user in vendor table). |
| Educational — 20-user | $4,320 (one-time perpetual) | Educational tiers. |
| Educational — 30-user | $5,160 (one-time perpetual) | Educational tiers. |
| Educational — 40-user | $5,890 (one-time perpetual) | Educational tiers. |
| Educational — 50-user | $6,420 (one-time perpetual) | Educational tiers. |
| Educational — 60-user | $6,840 (one-time perpetual) | Educational tiers. |
| Educational — 70-user | $7,210 (one-time perpetual) | Educational tiers. |
Upgrade pricing (from TRNSYS 17.x)
| Upgrade type | Price |
|---|---|
| Commercial — Single-user upgrade | $2,530 (one-time) |
| Commercial — 5-user upgrade | $4,290 (one-time) |
| Commercial — 10-user upgrade | $5,055 (one-time) |
| Educational — 10-user upgrade | $1,260 (one-time) |
| Educational — 20-user upgrade | $2,110 (one-time) |
| Educational — 30-user upgrade | $2,530 (one-time) |
TESS Component Libraries (add-ons — per-library pricing shown)
| Library (examples) | Educational Price (10-user) | Commercial Price (1-user) | Commercial Price (5-user) | Commercial Price (10-user) |
|---|---|---|---|---|
| Application Component Library | $105 | $210 | $357 | $420 |
| Cogeneration Component Library | $325 | $650 | $1,104 | $1,300 |
| Controls Component Library | $125 | $250 | $424 | $500 |
| Electrical Component Library | $205 | $405 | $688 | $810 |
| Ground Coupling Component Library | $270 | $535 | $908 | $1,070 |
| (see vendor table for all 14 libraries) | ||||
| --- | --- | --- | --- | |
| All 14 libraries (before discount) | $2,915 (educational) | $5,800 (1-user) | $9,848 (5-user) | $11,600 (10-user) |
| --- | --- | --- | --- | --- |
Discounts: 25% off for purchase of 5–9 libraries; 35% off for 10–13 libraries; 50% off for all 14.
TRNFlow (add-on)
| Version | Price (Commercial) | Price (Educational) |
|---|---|---|
| TRNFlow v1 | $3,160 (one-time) | $1,950 (one-time) |
Notes: All prices and tables above are taken directly from the official TRNSYS/TESS pricing pages. TRNSYS licenses are permanent (one-time purchase); vendor states there are no annual maintenance fees and version 18 maintenance releases are free to owners. Ordering is done via official TRNSYS distributors (TESS is the exclusive USA distributor).
Seller details
Thermal Energy System Specialists, LLC
Madison, Wisconsin, United States
1975
Private
https://www.trnsys.com/
https://www.linkedin.com/company/thermal-energy-system-specialists-llc
