Academic literature on the topic 'Trnsys building model'

The present study involves a validated TRNSYS model for solar assisted space heating system as applied to a residential building in Jordan using new detailed radiation models of the TRNSYS 17.1 and geometric building model Trnsys3d for the Google SketchUp™ 3D drawing program. The annual heating load for a building (Solar House) which is located at the Royal Scientific Society (RSS) in Jordan is estimated under climatological conditions of Amman. The aim of this paper is to compare the measured thermal performance of the Solar House with that modeled using TRNSYS. The results showed that the annual measured space heating load for the building was 6,188 kWh while the heating load for the modeled building was 6,391 kWh. Moreover, the measured solar fraction for the solar system was 50% while the modeled solar fraction was 55%. A comparison of modeled and measured data resulted in percentage mean absolute errors for solar energy for space heating, auxiliary heating, and a solar fraction of 13%, 7%, and 10%, respectively. T e validated model will be useful for long-term performance simulation under different weather and operating conditions.

Software for numerical simulation of various types of energy used in buildings, i.e. building energy simulation (BES), have become an essential tool for recent research pertaining to building physics. TRNSYS is a well-known BES used in both academia and the construction industry for a wide range of simulations, such as the design and performance evaluation of buildings and related facilities for heating, cooling, and ventilation. TRNSYS has a modular structure comprising various components, and each component is interconnected and compiled through a common interface using a FORTRAN compiler. Its modular structure enables interactions with various external numerical simulation tools, such as MATLAB, Python, and ESP-r. For ordinary simulations of building energy load using TRNSYS, the generic module Type 56 is usually recommended, which provides detailed physics modelling of building thermal behaviours based on unsteady energy conservation equations and Fourier’s law for each building material. However, Type 56 explicitly depends on the transfer function method to discretise the original differential equations; therefore, it cannot model nonlinear phenomena, such as latent heat and moisture transfer between a building surface and ambient air. In other words, the current TRNSYS cannot be used to estimate the effectiveness of evaporation during cooling, which is a typical passive design method. Hence, the authors developed a MATLAB/TRNSYS integration scheme, in which TRNSYS was modified to model simultaneous heat and moisture transfer from the wet roof surface of a building. This scheme enabled TRNSYS to calculate the rate of evaporative heat and moisture transfer dynamically from the roof surface, assuming a control volume approximation of the roof surface. Finally, the effect of evaporative cooling on the thermal performance of an Indian building was estimated using the modified model.

Coupled heat, air, and moisture transfers through building envelope have an important effect on prediction of building energy requirements. Several works were conducted in order to integrate hygrothermal transfers in dynamic buildings simulations codes. However, the incorporation of multidirectional hygrothermal transfer analysis in the envelope into building simulation tools is rarely considered. In this work, coupled heat, air, and moisture (HAM) transfer model in multilayer walls was established. Thereafter, the HAM model is coupled dynamically to a building behavior code (BES).The coupling concerns a co-simulation between COMSOL Multiphysics and TRNSYS software. Afterward, the HAM-BES co-simulation accuracy was verified. Then, HAM-BES co-simulation platform was applied to a case study with various types of climates (temperate, hot and humid, cold and humid). Three simulations cases were carried out. The first simulation case consists of the TRNSYS model without HAM transfer model. The second simulation case, 1-D HAM model for the envelope was integrated in TRNSYS code. For the third one, 1-D HAM model for the wall and 2-D HAM model for thermal bridges were coupled to the thermal building model of TRNSYS. Analysis of the results confirms the significant impact of 2-D envelope hygrothermal transfers on the indoor thermal and moisture behavior of building as well as on the energy building assessment. These conclusions are shown for different studied climates.

In this paper, the building energy performance modelling tools TRNSYS (TRaNsient SYstem Simulation program) and TRNFlow (TRaNsient Flow) have been used to obtain the energy demand of a domestic building that includes the air infiltration rate and the effect of natural ventilation by using window operation data. An initial model has been fitted to monitoring data from the case study, building over a period when there were no heat gains in the building in order to obtain the building infiltration air change rate. After this calibration, a constant air-change rate model was established alongside two further models developed in the calibration process. Air change rate has been explored in order to determine air infiltrations caused by natural ventilation due to windows being opened. These results were compared to estimates gained through a previously published method and were found to be in good agreement. The main conclusion from the work was that the modelling ventilation rate in naturally ventilated residential buildings using TRNSYS and TRNSFlow can improve the simulation-based energy assessment.

The window-to-wall ratio (WWR) significantly affects the indoor thermal environment, causing changes in buildings’ energy demands. This research couples the “Envi-met” model and the “TRNSYS” model to predict the impact of the window-to-wall ratio on indoor cooling energy demands in south Hunan. With the coupled model, “Envi-met + TRNSYS”, fixed meteorological parameters around the exterior walls are replaced by varied data provided by Envi-met. This makes TRNSYS predictions more accurate. Six window-to-wall ratios are considered in this research, and in each scenario, the electricity demand for cooling is predicted using “Envi-met + TRNSYS”. Based on the classification of thermal perception in south Hunan, the TRNSYS predictions of the electricity demand start with 30 °C as the threshold of refrigeration. The analytical results reveal that in a 6-storey residential building with 24 households, in order to maintain the air temperature below 30 °C, the electricity required for cooling buildings with 0% WWR, 20% WWR, 40% WWR, 60% WWR, 80% WWR, and 100% WWR are respectively 0 KW·h, 19.6 KW·h, 133.7 KW·h, 273.1 KW·h, 374.5 KW·h, and 461.9 KW·h. This method considers the influence of microclimate on the exterior wall and improves the accuracy of TRNSYS in predicting the energy demand for indoor cooling.

This review documents the present knowledge and knowledge gap in applying building energy simulation (BES) dynamic models to greenhouses. The focus of this review is to compile the literature on the BES dynamic model of greenhouse microclimate, covering materials, energy requirements and thermal blankets using the Transient System Simulation version 18 (TRNSYS 18) software. Fifty-two journal articles, mostly Science Citation Index (SCI) and Scopus index journals, on BES development and simulation of greenhouse microclimate, greenhouse energy requirement, covering materials and thermal blankets were reviewed. These researchers sought to optimise greenhouse crop production. The main features of the TRNSYS 18 software for BES development are outlined; each research consulted for this review successfully developed, simulated and validated its BES. However, none of these developed models included the vapour pressure deficit (VPD) as a greenhouse microclimate factor, an essential climate parameter. In conclusion, this study demonstrates that applying a BES developed using TRNSYS has excellent potential to optimise greenhouse crop production and help adapt appropriate climate control strategies and energy-saving techniques. However, it is recommended to include VPD in future BES model development.

In building energy simulations, the air infiltration and interzonal airflow are generally either not considered or calculated oversimplified. However, the effects of air infiltration and building airflow have an impact on the thermal comfort and the building’s energy load. The various zones in multi-zone buildings, the operation of windows, doors and mechanical ventilation make the system’s analysis complex and challenging. Building airflow affects pressure, temperature and moisture differences. Therefore, this study investigate the airflow inside a multizone building with changing user behavior, using a coupled building and system energy simulation. A decentralized air-only HVAC system provides the ventilation system with a control strategy, which variably adapts the airflow to the load in the individual zones. The effects of the air infiltration, interzonal airflow and mechanical ventilation in the building are investigated with a node and link network in TRNSYS using the airflow model TRNFLOW (COMIS). Investigating different variations of the ventilation rates and building’s airtightnesses, the results are shown by comparison with a reference model without airflow simulation. Finally, this study shows a comprehensive approach at low computational costs, determining the air quality, the thermal conditions and the airflow in a multizone building using an HVAC system.

The worldwide demographic and economic growth increases the global need for energy and directly contributes to climate change. In Morocco, the residential real estate is the third largest consumer of energy after transport and industry sectors. Thus, the aim of this study is to help engineers improve the energy performance of residential buildings by coupling the TRNSYS software both with a sensitivity analysis method and with an optimization tool. In fact, sensitivity analysis allows reducing the number of input parameters of any studied model, by ranking their degree of impact on any chosen output, and then discard the parameters with the least influence on that output. To do so, we developed algorithms in Python programming language to combine the open source library SALib, available in Github platform, with the TRNSYS software. Then, the chosen input parameters can be optimized through coupling the generic optimization program Genopt with TRNSYS. This article will also explain how these tools were applied to reduce the heating & air-conditioning needs of a high-energy consumption building in Morocco, while studying the variation of nineteen input parameters in TRNSYS. The main aim is to meet the energy performance requirement of the Moroccan thermal regulation for buildings.

In order to solve the problem of input fresh air overheating (cooling) in the cold supply (heating) season in severe cold regions, a soil source (BHE) combined with fresh air preheating (cooling) air conditioning system was studied in a net-zero energy building in Shenyang. Firstly, a hybrid TRNSYS-CFD simulation model based on TRNSYS and Fluent simulation software was established to simulate the operation and indoor temperature distribution of the air conditioning system in the building during a typical day in the summer (winter) season. The TRNSYS-CFD hybrid simulation allows simultaneous analysis of the operating characteristics of the air conditioning system and the real-time indoor temperature distribution. The results show that the accuracy of the hybrid simulation is compared with that of the TRNSYS stand-alone simulation by monitoring the temperature changes in each room. The room temperature from the TRNSYS stand-alone simulation is the average temperature of the room return air, while the room temperature from the hybrid simulation has a stratification effect and the simulation data is more valuable for reference.

The object of this research work is the comparison of the annual primary energy consumption of different types of heating systems, using two different calculation methods. The TRNSYS 18 software makes use of dynamic simulation, while the WinWatt software calculates according to the Hungarian implementation of EPBD (Decree No. 7/2006). There were differences in results which could be caused by the more precise calculation of the TRNSYS software. Differences were shown also in the weather data used by the two computer tools that had one of the most important effects on the results according this investigation. The number of heating degree days used by TRNSYS is 10% less, than that the Hungarian decree provides. Using the yearly measured energy consumption data given by the inhabitant of the investigated family house, the validation of the developed dynamic building energy simulation model by TRNSYS could be also achieved with good agreement.

In terms of master’s thesis HAM-Tools library designed for MATLAB/Simulink was modified for the use in simulations of houses in the Czech Republic. Modified library and its parts were described in detail and tested by the simulation of the one-zone and two-zones models of the house. The simulations of models with same parameters were also realized in program TRNSYS. The corresponding results achieved in mentioned simulation tools were compared to each other. The one-zone model created by using HAM-Tools library is tested by the simulation of ventilating, heating, cooling, and sources of moisture. A demonstration of the practical use of the simulation is carried out in the thesis, namely by examining the influence of the insulation thickness on the thermal performance of the house (resp. its heat loss) on real atmospheric conditions. Among others, available resources of meteorological data are mentioned and compared to each other. The function for processing of the meteorological data to a file compatible with the HAM-Tools library was created. It was also created a material data file containing commonly used materials of building structures in the Czech Republic and their parameters.

ITALIANO - La valutazione energetica di un edificio ha lo scopo di quantificare le risorse energetiche impegnate dall’edificio per alimentare i fabbisogni delle utenze, in rapporto a criteri di natura energetica/ambientale/economica. I criteri di valutazione attualmente impiegati sono: energia primaria, emissioni di CO2, costi, energia finale. L’uso di energia a livello di edificio è messo in relazione rispettivamente con le risorse energetiche primarie impegnate, con le emissioni di gas a effetto serra e con gli oneri gestionali. In una visione centrata sulla combinazione tra catena energetica dalle sorgenti all’edificio e edificio, l’impiego di questi criteri è funzionale al raggiungimento di obiettivi strategici di vasta scala verso cui il settore degli edifici è chiamato a convergere. In una visione centrata sull’edificio, l’impiego di questi criteri implica tuttavia che il risultato della valutazione sia dipendente da parametri estrinseci: le infrastrutture energetiche e il mercato dell’energia, interpretati come fattori di conversione, fattori di emissione, tariffe, secondo cui sono differenziati vettori e fonti. Una lettura estesa dell’uso di energia a livello di edificio dovrebbe prendere in considerazione sia gli aspetti di primo principio (conservazione dell’energia), che gli aspetti di secondo principio (degradazione dell’energia). Al fine di delineare un criterio di valutazione energetica del sistema edificio che sia in grado di differenziare vettori e fonti secondo il relativo potenziale termodinamico e che risulti indipendente da parametri estrinseci, abbiamo individuato come strumento l’exergia. Il criterio exergetico delineato quantifica l’exergia impiegata dall’edificio per alimentare gli usi delle utenze in base all’exergia dei vettori di rete e delle fonti rinnovabili on-site utilizzate. In una visione centrata sull’edificio l’exergia dei vettori e delle fonti è determinata in corrispondenza del confine del sistema. La prestazione exergetica “Exergy Performance” è valutata come il quantitativo netto di exergia da vettori di rete e da fonti rinnovabili on-site impiegato dall’edificio per alimentare gli usi delle utenze ed è espressa attraverso un indice “ExP” normalizzato rispetto a un anno di attività e a una unità di superficie. Data l’assunzione di una visione centrata sull’edificio, il criterio exergetico è da mettere in relazione con gli usi finali dell’energia, in quanto svincolato dall’assetto delle infrastrutture energetiche. Il criterio exergetico costituisce uno strumento di valutazione energetica del sistema edificio in grado di incidere sull’assetto degli usi finali dell’energia nel settore degli edifici. All’aspetto di stabilità della valutazione si combina l’aspetto di indirizzo delle scelte energetiche e di interazione con le strategie di decarbonizzazione quali il fuel-switching da combustibili fossili a vettore elettrico e l’incentivazione di vettori localmente zero-carbon. Il criterio exergetico risulta in linea con gli scenari descritti in Energy Roadmap 2050 nella misura in cui la sua applicazione porta verso l’efficienza degli usi finali dell’energia, verso l’elettrificazione e verso l’aumento della quota di consumo finale lordo di energia alimentato tramite fonte rinnovabili. ENGLISH - The aim of the building energy assessment is to quantify the energy sources used from a building to satisfy the users needs, through the application of energy or environmental or economic methods. The assessment methods currently applied are: primary energy, CO2 emissions, costs, final energy. The building energy demand is related respectively with the primary energy sources consumption, the greenhouse gases emissions, the running costs. From a point of view centered on the connection between the building and the energy supply chain, these methods are suitable in order to reach overall energy-environmental targets imposed on the building sector. From a building-centered point of view, these methods imply that the assessment results are dependent from parameters external to the system: the primary energy factors, the emissions factors, the economic rate. The energy sources and the energy carriers are diversified according to these parameters. These parameters are representative of the energy supply chain and the energy market. An overall building energy assessment should take in account both the First Principle features (energy conservation) and the Second Principle features (energy degradation). In order to define a building energy assessment method that is able to diversify the energy sources and the energy carriers according to the respective thermodynamic potential, and that is indipendent from parameters external to the system, we have identified the exergy as useful concept. The exergy method developed quantifies the exergy used from a building to satisfy the users needs, both from grid energy carriers and on-site energy sources. Assuming a building-centered point of view, the exergy of energy carriers and energy sources is determined on the system boundary. The "Exergy Performance" is defined as the net sum of exergy, both from grid energy carriers and on-site energy sources, used from a building to satisfy the users needs. It is expressed by an index "ExP" normalized with respect to one year of building running and one square meter of building floor. Assuming a building-centered point of view, the exergy method must be related to the energy end-uses, because it is indipendent from the energy supply chain and the energy market. The exergy method is able to address the choices about the energy end-uses structure in the building sector. Besides enabling a stable building energy assessment, the exergy method is converging towards the decarbonisation strategies as the fuel-switching from fossil fuels to electricity and the facilitation of locally low-carbon energy carriers. The exergy method is in compliance with the energy scenarios described in Energy Roadmap 2050, because its application lead to the energy end-uses efficiency, the electrification and the increase of gross final energy consumption fuelled from renewable energy sources.

Simulations of building performance or HVAC systems performance usually cover a time period of several weeks, months or even a year. Therefore, the computational demand of simulation models of buildings or HVAC systems can be quite constraining for their practical application. A substantial simplification of the simulated problem is usually necessary to reduce the computational demand. The paper reports the development of a quasi 1D model of a thermally activated layer with phase change material. The model was developed in MATLAB and subsequently implemented as a TRNSYS type. The model was validated with data obtained from experiments with thermally activated panels. The experimental panels contained a 15 mm thick layer of gypsum plaster comprising 30 wt.% of microencapsulated phase change material. Plastic tubes for liquid heat carrier (water in the presented study) were embedded at the bottom of the plaster layer. Thermal imaging was used to acquire the average surface temperatures of the panels in the experimental investigations. The experimental and numerical results were in a good agreement.

The successful widespread adoption of fuel cell systems is highly dependent upon the economics of the installation. This entails closely matching system capabilities with customer requirements. System sizing requires accurate predictions of building thermal and electrical loads. The TRNSYS-based building simulation model presented in this paper was developed to accurately integrate a fuel cell into the space heating, water heating, and cooling equipment in a building. The simulation tool determines water heating, space heating, and cooling loads for a single zone building on an hour-by-hour basis throughout the year using TMY2 weather data. It integrates empirical and theoretical state point models of the components of a fuel cell-based cogeneration and tri-generation system as well as baseline HVAC technologies. The key components include: hot water loops, stratified water tanks, boilers, furnaces, air conditioners, absorption chillers, space conditioning coils, heat rejection equipment, and ventilation controls. Various control options are incorporated to maintain setpoints, stage equipment, and limit power export. Renewable power systems such as PV and wind are also integrated into the model. The TRNSYS calculation engine iterates to find the state of the system for each hour. The simulation tool also includes post-processing capabilities to apply complex electric tariffs, organize annual simulation results, and manage multiple parametric runs. The tool has been developed to optimize the configuration of a fuel cell in a given building application and to complete numerous parametric runs to evaluate the economics of a system in different locations and building applications. This work was funded in part by the New York State Energy Research and Development Authority.

The design, construction, and operation of highly efficient residential buildings in hot and humid climates represent a unique challenge for architects, contractors, and building owners. In this paper, a case study on the performance of a residential building located in hot and humid location is presented. The building is a single-family house, which is modeled as a multi-zone building. The transient systems simulation program (TRNSYS) is used to simulate the building under Abu Dhabi’s typical meteorological year conditions. The results are presented in terms of the annual energy consumption and the indoor thermal comfort. The Predicted Mean Vote (PMV) is used to model the thermal comfort. In addition, the results of applying local building codes, Estidama, and international building codes, ASHRAE 90.2 and LEED, on the building’s performance are compared. The results will help in finding the effectiveness of these building standards in reducing the energy consumption of residential building in hot and humid regions.

In this paper, a complete zero-dimensional transient simulation model of a solar-assisted refrigeration plant is presented. In addition, a case study is discussed, aiming at determining the optimal configuration of the system, from the energetic point of view, in a specific application. The system under analysis consisted of several components: evacuated solar collectors, circulation pumps, variable speed pump, water storage tanks, auxiliary heater, single-stage H2O-LiBr absorption chiller, cooling tower, feedback controller, on/off hysteresis controller, single lumped capacitance building and controllers. The simulation was performed using the TRNSYS environment which is provided by a large component library. This software also includes a detailed database with weather parameters for several European cities. The system and the building were simulated using TRNSYS built in models. The system was simulated using specially designed control strategies and varying the main design variables. In particular, a variable speed pump on the solar collector was implemented in order to maximize the tank temperature and minimizing the heat losses. Finally a sensitivity analysis was also performed in order to calculate the set of synthesis/design parameters that maximize the total system efficiency.

A numerical model was developed in the TRNSYS environment (a transient simulation software) for Tri-Sol, a novel three-in-one solar energy system that produces electricity, hot water, and daylight for commercial buildings, to simulate its annual performance in terms of the three useful energy streams. Even though this model was developed for Tri-Sol, it can also be used for calculating the annual performance of similar concentrating PV/thermal (PV/T) and daylighting systems for various geographical locations. The model simultaneously calculates the codependent electrical and thermal performances, and calculates the useful daylight harvested by the building. The model is versatile and flexible in that any configuration of the modeled system can be properly designed using by changing parameters and inputs inside of TRNSYS. This model was used to predict the annual performance a single Tri-Sol PV/T module and a single Tri-Sol unit with five such modules as a function of its tilt and geographical location. Then, this model was used to compute the monthly performance of a Tri-Sol array for a 10,000 ft.2 building for varying geographical locations at a fixed tilt angle. These results show the utility and the power of the model for designing combined PV/T-daylighting solar technologies such as Tri-Sol.