Validation of TEKNOsim 5: Verification Against Different Standards and Building Energy Simulation Tools

The growth of building energy simulation tools has provided users with a variety of alternatives to model and simulate buildings. The algorithms used in each building energy simulation software are different and range from simple to highly complex. TEKNOsim is a simple design tool based on analytical and empirical algorithms. It is used for calculating building thermal loads and simulating indoor thermal climate. A new version of TEKNOsim has been released (Version 5) with a new interface and feature enhancements. This thesis aims to validate the algorithms used in TEKNOsim 5. The objective is to demonstrate the accuracy and reliability of the results that TEKNOsim 5 provides. The thesis is divided into three main parts: 1) Qualitative analysis of features of TEKNOsim 5 through a survey performed on a sample of users, 2) Analytical verification against three European Standards through verification procedures proposed by these Standards, and 3) Comparative verification against several building energy simulation tools through the Building Energy Simulation Test (BESTEST) cases. The survey results indicate that TEKNOsim 5 is perceived as an efficient tool with good functionality and a user-friendly interface with easy navigation. The survey results also suggest some future developments to make TEKNOsim more attractive to users. The analytical and comparative verifications indicate that TEKNOsim is a reliable and accurate tool for the evaluation of indoor thermal climate. It provides an accurate estimation of the peak sensible cooling load with relatively short model setup and simulation time. The peak heating loads are somewhat overestimated by TEKNOsim, but no more than 12 % compared to other simulation tools. A possible change, to reduce the deviation of TEKNOsim 5 results in comparison to other simulation tools, is to modify the way outdoor climate is defined and setup.A wide variety of available building energy simulation programs provide users with options to simulate simple as well as complex buildings. The use of any of these simulation tools depends upon the complexity of the building systems and the users’ needs. TEKNOsim is a simple tool for quick indoor climate simulations and thermal load calculations of a single zone. A new version of TEKNOsim has been launched with enhancements in the interface and simulation types computed by the software. The aim of this study was to validate the algorithm of TEKNOsim 5 by implementing a series of analytical and comparative test cases. In addition, a survey was conducted on a sample of users to obtain and analyze the user response on the new user interface. The analytical verification consisted of standardized test cases from three European Standards. The comparative verification was based on the ANSI/ASHRAE Standard 140-2011 and Building Energy Simulation Test (BESTEST) cases. The questionnaire scores indicated a collective agreement among the sample of users on the new user interface of the TEKNOsim 5. The new interface was perceived as user-friendly and easy to navigate through. The users also suggested additional features that could be added to the software to enhance its already powerful simulation and analysis capabilities. These included life-cycle costing and multi-zone simulations, among others. The analytical and comparative verifications indicated that TEKNOsim provides reasonably accurate and consistent results for indoor thermal climate simulations. The peak heating loads were slightly overestimated by TEKNOsim, but even in the worst-case scenario, the maximum variation between TEKNOsim and other simulation tools was no more than 12 %. TEKNOsim also provided an accurate estimation of the peak sensible cooling load with a very short simulation time. However, the deviation between TEKNOsim results and the reference values provided by the European Standards increased with the complexity of input data required for the simulations. Results of the verification cases used for this study suggest that TEKNOsim, despite being a simple tool, can be used for quick simulations during the initial design stage of a project with very good accuracy. The short learning curve period and the small amount of input data required for simulations constitute the main strengths of the software. TEKNOsim provides architects and HVAC engineers with the possibility to simulate a number of design variants in order to optimize their design with minimal modeling and computational efforts