International TRNSYS Developers‘ Team
University of Wisconsin – Solar Energy Laboratory (SEL), US
The SEL was founded in 1954. During the 1970s, their work in developing algorithms to describe the fundamental mechanics of heat transfer as it pertains to solar energy systems met with the advent of computer driven calculations and laid the groundwork for a software tool called TRaNsient SYStems (TRNSYS). Though originally developed to model the performance of solar energy applications, SEL researchers soon realized that TRNSYS was the first computerized tool for evaluating just about any type of energy system. This inherent flexibility in the software has allowed TRNSYS to continue to flourish for more than 50 years.
From the 1970s to the early 2000s, the SEL supported and developed TRNSYS, made it commercially available and in so doing, brought research carried out at the lab to the wider community. The SEL joined forces with Transsolar Energietechnik GmbH who had developed powerful modifications and additions to a TRNSYS building model. In 1993, the SEL joined forces with CSTB, who had developed a framework for creating interfaces for simulation oriented software tools and had created such an interface for TRNSYS.
Thermal Energy System Specialists (TESS), US
TESS was founded in 1994 by two University of Wisconsin – Solar Energy Laboratory graduates as a way of finishing up a few consulting projects between completing their graduate work and starting work „in the real world.“ A few consulting projects turned into more and more as TESS quickly became one of the first firms dedicated solely to energy modeling work. During the early years, TRNSYS-based work concentrated on modeling in support of research taking place at US National Labs. TESS’s TRNSYS work expanded into the private sector as the need for energy modeling in commercial projects became more widespread. During many of these projects, TESS found it necessary to write new components for TRNSYS and amassed a library of Types that they began offering commercially in 2001.
At the same time, energy modeling based research taking place at the Solar Energy Lab had become less TRNSYS oriented and more focused on other tools such as Engineering Equation Solver (EES). Needing to refocus their staff’s energy, the SEL formed a partnership with TESS to move day-to-day TRNSYS activities (support and training) from the academic setting over to TESS. Since then, TESS has continued to develop new libraries of components but has also largely taken over the core development of TRNSYS’s kernel and standard library as well. In 2018 they began partnering with Northland Numerics in order to bring TypeStudio to the TRNSYS community.
CSTB Sophia Antipolis, France
Werner Keilholz joined the TRNSYS group while working on his PhD in engineering at University of Nice, France, in 1992. The subject of his thesis was the development of an object oriented, multi-domain, intelligent simulation environment. One of the first applications of the software framework developed during this thesis was the IISiBat graphical front end for TRNSYS, which later evolved into TRNSYS Simulation Studio.
Werner Keilholz is in charge of coordinating the development of the graphical user interface for TRNSYS at CSTB Sophia Antipolis , as well as organizing support and the distribution of TRNSYS in France.