This section provides downloads and links to articles, papers, reports and diagrams, plus relevant and related guides.  

The project deliverables will also be accessible here, and shall be added to whilst the project progresses.

EXPERIMENTAL COMPARISON OF RADIANT CEILING PANELS AND CEILING PANELS CONTAINING PHASE CHANGE MATERIAL (PCM)

File size: 927kb

Authors: Dragos-Ioan Bogatu, Eleftherios Bourdakis, Ongun Berk Kazanci and Bjarne W. Olesen 

CLIMA 2019 Conference 27 May 2019, Romania

Two commercially available ceiling panels, one metal and one gypsum incorporating microencapsulated PCM were compared experimentally to determine their limitations and ability to provide an adequate indoor thermal environment. The experiments took place from February to May 2018 in a climate chamber at the Technical university of Denmark. In total, seven scenarios were evaluated, five with active cooling, where the flow rate and solar heat gains were varied, and two without. Results showed that according to EN 15251:2007, the RCPs maintained the best indoor thermal environment for 91 % of occupancy time in Category III – operative temperature between 22 oC and 27 oC, and 75 % in Category II – operative temperature between 23 oC and 26 oC, for a 140 kg/h flow rate and the reference solar heat gains. Alternatively, the PCM panels maintained Category III for only 48 % of the time, while only 30 % in Category II for a 220 kg/h flow rate and the reference solar heat gains. The PCM panel presented the ability to store the heat for a later time. However, the PCM panels’ solution proved inadequate in terms of heat storage capacity, pipe positioning and thermal conductivity while improvements are required in order to employ them in new and renovated buildings. 

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ESTIMATION OF LOAD DURATION CURVES FROM GENERAL BUILDING DATA IN THE BUILDING STOCK USING DYNAMIC BES-MODELS

File size: 665kb

Authors: Rana M. Mahmoud, Mohsen Sharifi, Eline Himpe, Marc Delghust and Jelle Laverge

CLIMA 2019 Conference 27 May 2019, Romania

Modelling and simulation of building stock is a valuable source of information for investigating the feasibility of implementing new heating and cooling system technologies. Some of these technologies have oversizing problem as the designers rely on their experience and previous knowledge. Building stock modelling can provide a solution for more accurate designing process. However, some of the current building stock modelling methods uses a representative building which can exclude whole ranges of the different combinations of building geometry and physical properties that can be crucial for heating and cooling load estimation. Therefore, we developed a methodology that allows faster and accurate building energy simulation (BES) multizone models from general building information of the whole building stock that is able to estimate load duration. This will help engineers and designers to decide on the system sizing at the early design stages. This paper presents first, the process of generating dynamically heating and cooling load duration curves by using BES-models from general geometrical data of the building stock. Second, we examine the process on a sample of the building stock where geometrical and physical parameters were varied. The workflow of the process has worked successfully, generating heating and cooling duration curves for 14 case studies. We observed that heating and cooling loads are highly influenced by different combinations of parameters. High glazing percentage affects highly the heat losses, thus more heating loads. Besides, for a west oriented building, the high glazing percentage combined with high internal gains can be the reason for significant cooling loads. In next steps, we are going to extend the current methodology to cover different building typologies within different climates across Europe.

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ENERGY AND THERMAL COMFORT PERFORMANCE EVALUATION OF PCM CEILING PANELS FOR COOLING A RENOVATED OFFICE ROOM

File size: 476kb

Authors: José Quesada Allerhand, Ongun Berk Kazanci, and Bjarne W. Olesen

CLIMA 2019 Conference 27 May 2019, Romania

The performance of suspended ceiling panels with phase change materials (PCM) for comfort cooling applications in office rooms was studied. The panel consisted of a metal casing, which encapsulates the PCM. Water can circulate through the pipes embedded in the panel to influence the latent energy storage of the material. To evaluate the performance of the PCM panels, a comparison with an all-air system and a thermally active building system (TABS) was made. Using TRNSYS 17, a recently renovated room in the Technical University of Denmark was modelled. The room was simulated during the cooling season with each of the three cooling systems in which the thermal environment and the corresponding energy use were determined. Operative temperature was maintained between 22 °C to 27 °C at least 90% of the occupied period with each system. Similarities were observed between the PCM and TABS systems. Energy savings of 15 % and peak cooling power reduction of 30 % compared with the all-air system were observed.  This study proved the common claim that PCM ceiling panels and TABS perform similar in terms of the created thermal indoor environment and energy savings, as well in terms of heat removal from the indoor space. Therefore, PCM ceiling panels could be used as an alternative for TABS in renovation projects while providing similar benefits to TABS.

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INVESTIGATION OF THE INFLUENCE OF OPERATION CONDITIONS ON THE DISCHARGE OF PCM CEILING PANELS

File size: 450kb

Authors: José Quesada Allerhand, Ongun Berk Kazanci, and Bjarne W. Olesen

CLIMA 2019 Conference 27 May 2019, Romania

The aim of this study was to determine favorable operation conditions for ceiling panels containing phase change materials (PCM) for cooling applications in office rooms. A recently renovated room in the Technical University of Denmark was used to have realistic boundary conditions. Using TRNSYS 17, the performance of the PCM panels during the cooling season in passive operation, discharge by air, and discharge by water circulation were investigated. A set of simulations were performed during a representative week in the cooling period. The room was simulated with no climatic systems, PCM without active discharge, ventilation during occupied hours only, and PCM with ventilation during occupied hours. Afterwards, two discharge methods were investigated, night ventilation at different flow rates and water circulation in pipes embedded in the panels. A parametric analysis was performed to identify the influence of operation factors in the thermal environment of the room. The parameters studied were the water flow rate, supply water temperature and circulation schedule as well as the conductivity of the PCM. After selecting different operating conditions of the water discharge, simulations were performed from May to October to observe the performance of the selected operation conditions. The results show that the PCM is more effective to provide adequate indoor thermal conditions if it is discharged actively by means of water. The parameters that affect the thermal indoor environment the most are the water circulation schedule, the water supply temperature, and the PCM thermal conductivity. The water flow rate did not have a significant influence. The study shows the importance of selecting an appropriate operation and control strategy for the PCM system. The process used in the study can be potentially used as a procedure for the design of similar climatic systems to determine if active discharge of the PCM is needed and if yes, which discharge method is needed.

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INTERACTION OF GEOTABS AND SECONDARY HEATING AND COOLING SYSTEMS IN HYBRIDGEOTABS BUILDINGS: TOWARDS A SIZING METHODOLOGY

File size: 766kb

Authors: Mohsen Sharifi, Rana Mahmoud, Eline Himpe, and Jelle Laverge

 

GEOTABS, a combination of TABS with a geothermal heat pump, is a promising heating and cooling system for decreasing greenhouse gas emissions in the building sector. However, TABS has a time delay when transferring energy from the pipes to the room. So, when the heat demand changes fast, TABS cannot properly compensate the heat demand. In order to solve this problem and maintain thermal comfort in the room, the concept of hybridGEOTABS proposes using a fast secondary system to assist the TABS. Yet, there is no integrated method for sizing both systems in a hybridGEOTABS building, considering the interaction between the secondary system and GEOTABS. This study will provide an integrated sizing methodology for hybridGEOTABS buildings. To that purpose, in this paper the interaction between the secondary system and TABS is investigated for two different scenarios by using a preference factor between the TABS and the secondary system. The methodology starts from heat demand curves, an analytic model for TABS, and optimal control principles for TABS to minimize the total energy use while providing thermal comfort. Finally, the method is used for 4 case studies in different scenarios with different secondary systems. Preliminary results of this research indicate that the secondary system type doesn’t have effect on the strategy of sizing.  Therefore, designer can decide about secondary system type with investment and operating cost analysis.   

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TOWARDS REAL MPC IMPLEMENTATION IN AN OFFICE BUILDING USING TACO

File size: 2mb

Authors: Filip Jorissen, Damien Picard, Iago Cupeiro Figueroa, Wim Boydens, Lieve Helsen.  Paper from:

5th International High Performance Buildings Conference Purdue July 9-12 2018

Model predictive control (MPC) is a promising alternative to rule-based control since it is more suitable to control increasingly complex buildings and thereby realising energy savings and comfort improvement. Practical implementations are however hampered by the complexity of MPC and the expertise required for developing MPC. Therefore, a toolchain for automated control and optimization (TACO) has been developed that automatically translates an object-oriented Modelica model into an efficient MPC code. Since object-oriented models from the Modelica IDEAS library are used, the expertise requirement and development time are reduced significantly. TACO has, however, not yet been applied to a real building and its robustness in real operation still must be demonstrated. The purpose of this paper is to provide a comprehensive overview of the steps that are proposed for implementing an MPC using TACO.

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