Conference Agenda

Session
Session W1.6: Improving indoor environmental quality
Time:
Wednesday, 01/Sept/2021:
10:30 - 12:00

Session Chair: Hilde Breesch, KU Leuven
Session Chair: Dimitrov Bolashikov, Daikin Europe NV
Location: Concert Hall - Concertzaal
't Zand 34, Bruges

External Resource: Click here to join the livestream. Only registered participants have received the access code for the livestream.
Presentations
10:30 - 10:48

Computational assessment of occupant-centric radiant cooling solutions

Helene Teufl, Ardeshir Mahdavi

Department of Building Physics and Building Ecology, TU Wien, Vienna, Austria

Aim and Approach

(max 200 words)

The aim of this contribution is to computationally model and evaluate a number of previously proposed alternative radiant cooling designs [1]. The development of these solutions is guided by three main concepts. The first concept aims at positioning cooling elements in close proximity to occupants. This approach is suggested to enhance both energy efficiency and personal control. The second concept concerns the surface temperature of the radiant element. In comparison to classical radiant cooling solutions, the alternative strategies are meant to allow for and accommodate surface condensation via integrated drainage elements. Thus, lower panel surface temperatures are possible. The third concept aims at incorporating an appropriately selected vegetation layer into the designs [1, 2]. Such a layer could contribute to the appearance of the radiant panels. Moreover, placed below the vertical radiant panel, the container for the layer's substrate can act as the collector of condensed water. The paper entails a detailed computational examination of the effectiveness of the proposed solutions.

Scientific Innovation and Relevance

(max 200 words)

Buildings' increasing cooling energy use has been attributed to phenomena such as global warming and urban heat islands [3]. This underlines the need for innovative cooling solutions. In this context, radiant cooling technologies have been promoted because they have the potential to improve the energy efficiency as well as occupants' thermal comfort [4-7]. Nonetheless, some important aspects must be considered when designing and implementing radiant cooling systems (e.g., buildings' climatic context, position of the radiant elements relative to occupants, water vapor condensation risk). The previously mentioned alternative radiant cooling solutions are intended to address these aspects [1]. The contribution highlights the potential of these solutions in view of energy efficiency and thermal comfort.

Preliminary Results and Conclusions

(max 200 words)

The paper presents the result of a virtual examination of prototype designs of occupant-centric radiant cooling systems in an office setting. A software solution is developed to probe multiple design variations including panels positioned on one or two sides of typical workstations. The effectiveness of the solutions is explored for different climatic regions (from hot dry to hot humid) and multiple surface temperature regimes (involving both temperatures above and below the dew-point temperature) are considered. The outcome of the case study shows that occupant-centric radiant cooling can improve both energy efficiency and users' thermal comfort. Moreover, limitations of the proposed configurations – particularly in extremely hot and humid conditions – are illustrated, and potential complementary measures (i.e., additional convective cooling via task elements) are examined. The developed software solution can offer a preliminary virtual assessment of a variety of technical solutions in a variety of climatic boundary conditions.

Main References

(max 200 words)

1. Mahdavi, A., Teufl, H., 2020. Occupant-centric radiant cooling solutions. Requirements, designs, assessment. In PLEA 2020 (Ed.): Proceedings of the PLEA 2020 Conference – to appear.

2. Gau, U., 2005. Eine mobile Kühlwand für Büroräume. Master Thesis: TU Wien.

3. IEA, 2018. The Future of Cooling - Opportunities for energy-efficient air conditioning. https://www.iea.org/reports/the-future-of-cooling

4. Rhee, K.N., Kim, K.W., 2015. A 50 year review of basic and applied research in radiant heating and cooling systems for the built environment. Building and Environment 91, pp. 166–190. DOI: 10.1016/j.buildenv.2015.03.040.

5. Rhee, K.N., Olesen, B.W., Kim, K.W., 2017. Ten questions about radiant heating and cooling systems. Building and Environment 112, pp. 367–381. DOI: 10.1016/j.buildenv.2016.11.030.

6. Tian, Z., Love, J.A., 2009. Energy performance optimization of radiant slab cooling using building simulation and field measurements. Energy and Buildings 41 (3), pp. 320–330. DOI: 10.1016/j.enbuild.2008.10.002.

7. Memon, R.A., Chirarattananon, S., Vangtook, P., 2008. Thermal comfort assessment and application of radiant cooling: A case study. Building and Environment 43 (7), pp. 1185–1196. DOI: 10.1016/j.buildenv.2006.04.025.



10:48 - 11:06

Occupant-centric control of transparent dynamic façades through an integrated co-simulation framework

Luigi Giovannini, Manuela Baracani, Fabio Favoino, Valentina Serra

Polytechnic University of Turin, Italy

Aim and Approach

(max 200 words)

The use of adaptive transparent envelope technologies (adaptive glazings, dynamic shading devices, etc..) in buildings could yield significant performance improvements compared to static solutions, due to their ability of modulating the incoming solar radiation according to external inputs. As a consequence, these components are difficult to operate, as their behaviour simultaneously affects different physical domains, interdependent and often conflicting. Current research trends have mainly focused on controlling these technologies to minimise building energy use, while comfort aspects (thermal and visual comfort) related to their operation are generally overlooked. Nevertheless, understanding the relationship between different performance requirements in operating such dynamic systems is of outmost importance.

In this framework, this paper presents a simulation framework to evaluate the performance of adaptive transparent façades in a comprehensive way, and this is demonstrated by evaluating the performance of different mono-objective control strategies, aimed at the optimisation of either energy or comfort aspects. This is done for an office case study located in Rome and equipped with an active adaptive façade technology modulating the entering solar radiation. This enabled investigating the strengths and drawbacks of the control strategies considered, as well as their impact over physical domains these were not conceived to optimise.

Scientific Innovation and Relevance

(max 200 words)

Current Building Performance Simulation tools have limited capability in evaluating the performance of transparent adaptive technologies [1], including the influence of the control strategy, due to their inability to: (a) flexibly vary the thermo-optical properties of the materials; (b) evaluate in an integrated way the mutual effect of an adaptive envelope technology in different physical domains. As a result, most of the studies evaluating the performance of adaptive envelope components focus only on their effect on energy related aspects, visual or thermal comfort aspects, not taking into account the mutual influence between these domains. This paper presents an integrated simulation framework enabling the evaluation of the performance of active adaptive envelope technologies according to energy, thermal and daylight related aspects in a coupled way. This was done by managing together BPS tools aimed at evaluating the different aspects influenced by the adaptive component behaviour. Specifically, the use of Rhinoceros parametric plugin Grasshopper and its add-on Ladybug/Honeybee allowed different BPS tools to be managed through the same interface. EnergyPlus was used for the thermal and energy analysis while DAYSIM and Radiance were used for the daylight analysis. Finally, the data integration between these tools was achieved through purposely built scripts.

Preliminary Results and Conclusions

(max 200 words)

The results obtained for the office case study considered show that the control strategies analysed, when aimed at optimising a single objective (i.e. energy performance, visual or thermal comfort, etc..), have, at different extents, drawbacks on the other domains they influence. To prevent or reduce these drawbacks, the control strategies should be devised as most suitable trade-off between energy and comfort related aspects. Moreover, the specific features of the space considered, as well as the climate of the site, show to have a significant influence on the effectiveness of a control strategy. Based on the results obtained, in order to successfully meet the desired goals, a specific control strategy should be purposely conceived or optimised for each specific space, taking into account its characteristics and the local climate as well. The integrated simulation approach proposed in the present work can play a key role in the conception and/or optimisation of such control strategies: its ability to overcome the main gaps in the currently available simulation strategies allows in fact a simultaneous and accurate evaluation of the effects of the behaviour of an active adaptive envelope component on energy, visual comfort and thermal comfort related aspects.

Main References

(max 200 words)

[1] R.C.G.M. Loonen, F. Favoino, J. Hensen, M. Overend. Review of current status, requirements and opportunities for building performance simulation of adaptive facades, Journal of Building Performance Simulation 10(2) (2017) 205-223.

[2] L. Giovannini, F. Favoino, A. Pellegrino, V.R.M. Lo Verso, V. Serra, M. Zinzi. Thermochromic glazing performance: From component experimental characterisation to whole building performance evaluation. Applied Energy 251 (2019) 11335.

[3] L. Giovannini, F. Favoino, V.R.M. Lo Verso, A. Pellegrino, V. Serra. A Simplified Approach for the Annual and Spatial Evaluation of the Comfort Classes of Daylight Glare Using Vertical Illuminances. Buildings 8 (2018), 171.

[4] E. Arens, T. Hoyt, X. Zhou, L. Huang, H. Zhang, S. Schiavon. Modeling thecomfort effects of short-wave solar radiation indoors. Building and Environment 88 (2015), 3-9.

[5] F. Favoino, F. Fiorito, A. Cannavale, G. Ranzi, M. Overend. Optimal control and performance of photovoltachromic switchable glazing for building integration in temperate climates. Applied Energy 178 (2016), 943-961.

[6] J.M. Dussault, L. Gosselin. Office buildings with electrochromic windows: A sensitivity analysis of design parameters on energy performance, and thermal and visual comfort. Energy and Buildings, 153 (2017), 50-62.



11:06 - 11:24

Optimization workflow for the design of efficient shading control strategies

Abel Sepúlveda, Francesco De Luca, Jarek Kurnitski

Tallinn University of Technology, Estonia

Aim and Approach

(max 200 words)

The main aim of this investigation is to study optimal shading strategies to improve the indoor visual comfort and energy performance at educational buildings in Estonia.

The goals are the following:

1. Optimization of control algorithms for internal roller fabric systems to achieve a suitable daylight provision and glare performance.

2. To prove the viability of these different shading algorithms to contribute achieving the energy consumption of nearly energy zero buildings (nZEB) according to the Estonian regulation [1, 2] and minimum requirements in terms of daylight provision and glare protection defined by the novel European standard EN 17037:2018 [3].

We used a simulation-based methodology and single zone approach (room level) [4]. The software used are Radiance and EnergyPlus for daylight and energy calculations, respectively. The cases study consists in three existing auditoriums with different orientations (east, south and west) located in Tallinn University of Technology campus. We considered interior roller fabrics as main shading device. Four different complex fenestration systems are analyzed and shading controls based on vertical illuminance, direct normal irradiance and daylight glare probability (DGP) are tested.

Scientific Innovation and Relevance

(max 200 words)

Visual comfort has high impact on students’ academic performance and health. Estonian energy consumption requirements aim to reach the nearly Energy Zero Building (nZEB) category for new and renovated buildings. In addition, the fulfillment of the actual Estonian daylight requirements based on daylight factor have been proved insufficient to ensure a realistic daylight provision in residential, office and educational buildings [5]. There is a lack of consideration of daylight glare phenomenon during early stages and refurbishment plans in Estonia despite of the low sun altitude [6, 7]. Furthermore, the fulfillment of requirements in terms of daylight provision and glare protection defined by the European standard EN 17037:2018 in combination with nZEB energy requirements defined by the Estonian regulations must be studied.

Preliminary Results and Conclusions

(max 200 words)

It is possible to achieve suitable trade-off between daylight provision, glare protection and energy performance in educational buildings in Estonia. This achievement can be reached combining interior roller fabric and shading control strategies based on variables such as vertical illuminance at eye level, direct normal solar radiation and DGP are crucial to achieve an adequate overall performance. A suitable choice of the fabric and shading control algorithm thresholds helps to optimize the overall performance depending on the room orientation, surrounding buildings and weather conditions. Moreover, the use of the interior roller fabric is key to improve glare protection without increasing lighting consumption. This study would help architects and practitioners to choose adequate CFSs and their control at both, in early stages and refurbishment plans of educational buildings in Estonia.

Main References

(max 200 words)

[1] Estonian Government, Minimum requirements for energy performance. Annex 68, RT I, 24.01.2014, 3, (2012). https://www.riigiteataja.ee/en/eli/520102014001.

[2] Estonian Government, Ordinance N° 58. Methodology for calculating the energy performance of buildings. RTI,09.06.2015, 21, (2015).

[3] European comission, BS EN 17037:2018: Daylight in buildings, (2018). https://www.en-standard.eu/bs-en-17037-2018-daylight-in-buildings/.

[4] B. Bueno, A. Sepúlveda, A Specific Building Simulation Tool for the Design and Evaluation of Innovative Fenestration Systems and their Control, in: Nternational Build. Perform. Simul. Assoc. -IBPSA- Build. Simul. 2019. 16th Conf. IBPSA. Proc. Rome, Italy, 2-4 Sept. 2019, 2019. http://publica.fraunhofer.de/dokumente/N-565205.html.

[5] F. De Luca, M. Kiil, R. Simson, J. Kurnitski, R. Murula, Evaluating Daylight Factor Standard through Climate Based Daylight Simulations and Overheating Regulations in Estonia, in: Proc. Build. Simul. 2019 16th Conf. Int. Build. Perform. Simul. Assoc., 2019.

[6] Sepúlveda, A., De Luca, F., Thalfeldt, M., & Kurnitski, J. (2020). Analyzing the fulfillment of daylight and overheating requirements in residential and office buildings in Estonia. Building and Environment, 107036.

[7] F. De Luca, T. Dogan, J. Kurnitski, Methodology for determining fenestration ranges for daylight andenergy efficiency in Estonia, in: Simul. Ser., 2018. https://doi.org/10.22360/simaud.2018.simaud.007.



11:24 - 11:42

Tool Development for Automatic Simulation of central and decentral Heat Supply Scenarios and Application to a district in the City of Mainz, Germany (SimStadt 2.0 project)

Verena Weiler1, Eric Duminil1, Bodo Balbach2, Bastian Schröter1

1University of Applied Sciences Stuttgart, Germany; 2Mainzer Stadtwerke AG

Aim and Approach

(max 200 words)

Often enough, when new constructions or changes in existing built-up areas are planned, energetic assessments such as the choice among heat supply options, are done at a late stage in the process, with key decisions on the area already made. Our tool, called SimStadt, enables local decision makers to perform an early-stage analysis of possible planning scenarios, with limited data requirements on the technical backgrounds and exact design of potential future scenarios.

SimStadt is a scientific workflow management platform, which can be coupled to a number of external tools and libraries. The existing functionalities have been described in various publications ([1]–[4]) and shall not be the focus here. The new developments in the (ongoing) SimStadt 2.0 project are the connection of heat demand calculations to heat supply models. They are modelled in INSEL (www.insel.eu), with the district heating network dimensioned in more detail in STANET (www.stafu.de/en). Additionally, an energy components library contains relevant parameters for various heat supply models. The new development was tested with a district of 65 buildings in Mainz, Germany, where options for a central network system were compared against a decentral air-water heat pump system along technical and economic indicators.

Scientific Innovation and Relevance

(max 200 words)

Most urban building energy simulation tools (UBEM) need a large amount of input data and/or proficient users ([5], [6]). One innovation in the SimStadt 2.0 project and tool development lies in the fact that the simulation environment can be used by non-experts while maintaining sufficient results accuracy for strategic decision-making and comparing various options in a scenario-based approach. This semi-automatic process is facilitated by the architectural design of the SimStadt platform: a CityGML model used as key input contains most of the required information on building geometry; second, a pre-defined set of heating system configurations with underlying, INSEL-based simulation models as well as a library of component specifications from the most important manufacturers enables the user to simply choose one or more heat supply options.

Simulation results are given as tables containing important technical and economic parameters such as total investment and operating cost and GHG emissions of a given scenario, and can be visualized via 3D maps. Thus, multiple scenarios can be easily compared against each other.

Preliminary Results and Conclusions

(max 200 words)

Our approach was validated by comparing the modelling results for CHP plus centralized heating network with measured data from 2017. While actual data give a total annual heat demand of 2,005MWh, our model gives 2,144MWh, i.e. a deviation of 7%, with the simulation mainly over-estimating space heating demand for office buildings. This can partly be attributed to refurbishments that are not yet accounted for in the CityGML building data that serves as input to the simulation. Comparing the values on the supply side, measured data give 2,924MWh, which we underestimate by only 4%. When looking at the monthly comparison, differences are higher especially in March and November, when a typical heating season in Germany starts or ends (-34% and +65%, respectively). Comparing hourly values, the mean bias error is less than 10%.

Results from the model that applies decentral heat pumps in all buildings cannot be validated with measured data, since it is theoretical. However, the model was validated by comparing it to another heat pump model that itself had already been validated with measured data from a different project.

Future analysis will be aimed at identifying the reasons for the differences between measurement and simulation and consequently reducing them.

Main References

(max 200 words)

[1] R. Nouvel et al., “SIMSTADT , A NEW WORKFLOW-DRIVEN URBAN ENERGY SIMULATION PLATFORM FOR CITYGML CITY MODELS,” in CISBAT 2015, 2015, pp. 889–894.

[2] U. Eicker, D. Monien, É. Duminil, and R. Nouvel, “Energy performance assessment in urban planning competitions,” Appl. Energy, vol. 155, pp. 323–333, 2015.

[3] M. Zirak, V. Weiler, M. Hein, and U. Eicker, “Urban models enrichment for energy applications: Challenges in energy simulation using different data sources for building age information,” Energy, vol. 190, p. 116292, 2019.

[4] V. Weiler and U. Eicker, “Individual Domestic Hot Water Profiles for Building Simulation at Urban Scale,” in IBPSA Building Simulation Conference, 2019.

[5] J. Allegrini, K. Orehounig, G. Mavromatidis, F. Ruesch, V. Dorer, and R. Evins, “A review of modelling approaches and tools for the simulation of district-scale energy systems,” Renew. Sustain. Energy Rev., vol. 52, pp. 1391–1404, 2015.

[6] W. Li, Y. Zhou, K. Cetin, J. Eom, Y. Wang, and G. Chen, “Modeling urban building energy use: A review of modeling approaches and procedures,” Energy, vol. 141, pp. 2445–2457, 2017.