Conference Agenda

Overview and details of the sessions of this conference. Please select a date or location to show only sessions at that day or location. Please select a single session for detailed view (with abstracts and downloads if available).

Please note that all times are shown in the time zone of the conference. The current conference time is: 17th May 2022, 07:21:01 CEST

 
 
Session Overview
Session
Session T2.9 (Online Track): Practice and industry related case studies
Time:
Thursday, 02/Sept/2021:
10:30 - 12:00

Location: Virtual Meeting Room 3

External Resource: Click here to join the Zoom Meeting
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Presentations
10:30 - 10:48

Case study of evaporative cooling technologies for Australian office buildings

Paul Bannister1, Hongsen Zhang2, Stephen White3

1DeltaQ Consulting Service Pty Ltd, Australia; 2Enerefficiency Pty Ltd, Australia; 3Commonwealth Scientific and Industrial Research Organisation, Australia

Aim and Approach

(max 200 words)

This paper summarises work, undertaken by the authors as part of the PRIME Net Zero Energy HVAC Technology project, investigating the potential for a range of evaporative cooling technologies to reduced HVAC energy consumption for office buildings in Australia.

A medium-sized office building model was simulated IES a range of configurations using weather files of typical locations across the 8 Building Code of Australia (Volume 1) climate zones in Australia. The HVAC types used in the simulation include:

(1) Conventional AHU-VAV system, which was used as the baseline.

(2) Model (1) plus direct/indirect evaporative cooling.

(3) Model (1) plus dewpoint cooler and direct evaporative cooling.

(4) Model (1) plus dewpoint cooler only

(5) Model (1) plus direct/indirect evaporative cooling and desiccant wheel.

Scientific Innovation and Relevance

(max 200 words)

The use of evaporative cooling technologies provides significant opportunities for reduced energy use particularly in cooler and less humid climates, but they have achieved little penetration in the Australian office sector. The purpose of the study is to better understand the potential energy savings associated with a range of conventional evaporative cooling technologies (direct and indirect evaporative cooling) and less common approaches (dewpoint coolers, indirect evaporative cooling in combination with desiccant wheel). For this study they have been assessed in the context of otherwise conventional Australian office design and in particular are based on the use of a variable air-volume air-conditioning system.

Preliminary Results and Conclusions

(max 200 words)

It was found that

(1) Configurations (3) and (4) offer the best energy/greenhouse savings (13-44%, dependent on climate zone) most for climate zones with the exception of Climate Zones 1 (Darwin) & 8 (Thredbo).

(2) The reactivation energy required for configuration (5) overshadowed the electricity savings achieved. If “free” reactivation heat were to be available, then this configuration provided the best outcomes in Climate Zone 1. Furthermore in Climate Zone 8 it was found that the chiller could be wholly replaced by desiccant wheel and evaporative cooling system potentially reducing the system capital cost.

Some additional simulations were run which demonstrated that further optimisation of control sequences could further extend the benefits of model (4) to 55% in the most favourable climate zone (Climate Zone 3 - Alice Springs).

This preliminary study has indicated significant potential for evaporative technologies in less humid and cooler climates in particular. Further work is required to understand the full potential of evaporative cooling technologies in more detail, particularly with respect to their application in other HVAC systems (especially those using higher supply air temperatures, such as underfloor systems) and other building types.

Main References

(max 200 words)

To be provided.



10:48 - 11:06

Optimization of electric lighting in a hospital emergency room - A case study

Zhafirah Ajrina, Desliana Putri Pratiwi, Rizki Armanto Mangkuto, Revantino Revantino

Institut Teknologi Bandung, Indonesia

Aim and Approach

(max 200 words)

Lighting design has become an important major factor in building construction planning. Optimum lighting is required to achieve an adequate visual performance while reducing visual discomfort, particularly, when executing tasks that require high accuracy. One of the most critical examples of lighting design is lighting in the healthcare facilities or hospitals, especially in emergency room. It is one of the parts in a hospital that provides early treatment for patients who suffer illness and injury, which can endanger their life-being. Therefore, it should be designed to obtain specific room requirement and lighting standard, since it can effectively build the room environment to influence physical and mental health, thus provides comfort of not only the patients, but also the medical staff. This paper aims to propose an optimized electric lighting design for Karya Dharma Kembang Tanjung Hospital, in this case at the emergency room, by means of modelling and simulation. Computational model of the room was built in DIALux Evo, and the simulation was executed with and without daylighting scene of four room types (lobby, examination room, treatment room, and corridor). Four different variables were observed and simulated for obtaining the optimum result.

Scientific Innovation and Relevance

(max 200 words)

Lighting optimization in healthcare area was mostly done using several similar input variables, namely the polar diagram luminaires and reflectance walls. This research considers the variety of room type as well as the lighting standard in the emergency room, which is the most critical space in a hospital. This study also focuses on the treatment room to observe the local lighting and the influence of the visual discomfort from the doctor’s perspective. This would be relevant to solve one of the problems in current pandemic situation, where many patients are found in the emergency room. In this case, simulation may help providing several lighting design solutions, which can enhance the accuracy of examination by the medical staff.

Preliminary Results and Conclusions

(max 200 words)

The average horizontal illuminance and uniformity in the overall room type, in the case without daylight, has achieved the requirement. However, the task lighting condition in the examination and treatment room need to be further adjusted in order to enhance the visual performance. In this case, local lighting is applied to the area of patient's bed (mattress). The optimum lighting design for examination room is achieved using Phillips TBS165 G 2xTL5-28W HFS C6 luminaires with wall reflectance of 0.8. The selected option is based on the highest average illuminance value of those rooms compare to other types of luminaires, thus resulted good uniformity of 0.76. Then, the enhancement of lighting in treatment room is conducted by rotating the luminaire by 40° of normal from the right side of mattress orient to the doctor, it yields the smallest vertical illuminance and UGR values. However, the optimization of luminaire angle is only occurred when the observation area is along the patient's mouth up to the abdomen. Further investigation is needed when the observation area is more extensive to ensure good lighting performance and visual comfort in the room.

Main References

(max 200 words)

1. A. H. Primanti, R. A. Mangkuto, D. P. Sari, and B. A. Kautsar, “Optimization of artificial

lighting in physiotheraphy room of Hasan Sadikin Hospital,” AIP Conf. Proc., vol. 2088,

no. 1, p. 040001, Mar. 2019.

2. G. F. M. Lima, J. Tavares, I. S. Peretta, K. Yamanaka, A. Cardoso, and E. Lamounier,

“Optimization of lighting design usign Genetic algorithms,” in 2010 9th IEEE/IAS

International Conference on Industry Applications - INDUSCON 2010, Sao Paulo, pp.

1–6, Nov.2010.

3. "Hospital Lighting Guide and Standards". BFW Inc.

4. Kementerian Kesehatan. 2012. Pedoman Teknis Bangunan Rumah Sakit Ruang

Gawat Darurat, Direktorat Bina Pelayanan Penunjang Medik dan Sarana Kesehatan,

Kementerian Kesehatan RI.



11:06 - 11:24

Reallocation of heating consumption and costs based on decoupling of household heat metering data

Yuying Li1, Fan Yang1, Peng Xue1, Rui Zhao2, Jingchao Xie1, Jiaping Liu1

1Beijing University of Technology, China, People's Republic of; 2Tianjin Thermal Power Co., Ltd., Tianjin, China

Aim and Approach

(max 200 words)

Implementing household heat metering and charging is a significant way to realize building energy conservation in northern China, but the current heat metering has two contradictions for promotion. The first fact is the corner users have a higher heating consumption than the center users with its bigger area of external envelope, and the second is the heating costs of high-temperature users will increase sharply due to the phenomenon of adjacent room heat transfer (ARHT). This study selects a residential building in Tianjin, China as a research object, and field measurement and energy simulation are adopted to reveal every process of heat transfer including ARHT. The heating load and ARHT are further reallocated for each unit, and a new heat charging scheme is then proposed. The results provide a case study for the fair allocation of heat charging, which is vital to the implementation of household heat metering in China.

Scientific Innovation and Relevance

(max 200 words)

This study establishes a physical building model by EnergyPlus based on real design documents, and Python programming is employed to analyze the heat transfer process and create the indoor temperature decoupling model. It helps to clearly identify the user’s heating behavior and precisely calculate the additional heating consumption and heating costs of ARHT. Comprehensively considering the influence of the corner user’s large heating consumption and ARHT problem on the theoretical heating consumption, this research also calculates the heating consumption at different locations and ARHT with various temperature differences and occupancy rates. Finally, the reallocation of heating consumption and heat charging is proposed.

Preliminary Results and Conclusions

(max 200 words)

After correcting the heating consumption of the whole building, the heating consumption of corner unit on the top floor decreases 33% of it before reallocation, and the heating cost also reduces by about 20%. The heating consumption of center users increase 20%, and heating costs increase above 10% than before. The ARHT increases with the increase of the temperature differences between adjacent rooms. When the heat transfer only occurs to one adjacent room, the ARHT of a unit could take up around 25% of the total heating consumption with the temperature difference of 10 degrees. With a rather low occupancy rate of the whole building, the heat loss will be twice of the basic heating consumption of an ordinary room with a higher vacant adjacent room numbers. The ratio of ARHT to the real total heating consumption could stay around 10% and even reach up to 50%, and the heating costs of high-temperature users could increase 70% during one heating season. This quantitative research provides a case study for heat charging, which pushes the heat fee policy towards further fair allocation.

Main References

(max 200 words)

[1] Canale L, Battaglia V, Ficco G, Puglisi G and Dell’Isola M. Dynamic Evaluation of Heat Thefts Due to Different Thermal Performances and Operations between Adjacent Dwellings. Applied Sciences, 2020, 10(7), 2436.

[2] Cholewa T, Siggelsten S, Balen I, Ficco G. Heat cost allocation in buildings: Possibilities, problems and solutions. Journal of building engineering, 2020, 101349.

[3] Ling J, Li Q, Xing J. The influence of apartment location on household space heating consumption in multi-apartment buildings. Energy and Buildings, 2015, 103: 185-197.

[4] Lukic N, Nikolic N, Timotijevic S, Tasic, S. Influence of an unheated apartment on the heating consumption of residential building considering current regulations—Case of Serbia. Energy and Buildings, 2017, 155, 16-24.

[5] Michnikowski P. Allocation of heating costs with consideration to energy transfer from adjacent apartments. Energy and Buildings, 2017, 139: 224-231.

[6] Siggelsten S. Reallocation of heating costs due to heat transfer between adjacent apartments. Energy and Buildings, 2014, 75, 256-263.

[7] Xue P, Yang F, Zhang Y, Zhao MJ, Xie JC, Liu JP. Quantitative study on adjacent room heat transfer: Heating load and influencing factors. Sustainable Cities and Society, 2019, 51, 101720.



11:24 - 11:42

Feasibility study for combined mist evaporation cooling with carbon dioxide enrichment for greenhouse cultivation

Craig Edward Farnham1, Mami Oishi2, Jihui Yuan3

1Osaka City University, Japan; 2Research Institute of Environment, Agriculture and Fisheries, Osaka Prefecture; 3Toyohashi Univeristy of Technology

Aim and Approach

(max 200 words)

Greenhouse farming in many regions of the world faces the issue of overheating. When natural ventilation nor mechanical ventilation is sufficient to prevent overheating, a low-cost solution is evaporative cooling, often with wetted media and strong mechanical ventilation. Fine mist sprays from high pressure nozzles can evaporate completely without this strong ventilation, and may be sufficient with natural ventilation to prevent overheating, as well as prevent air saturation which would block further mist evaporation, thus limiting the cooling effect and causing undesirable wetting of the plants and fruit.

Increased carbon dioxide (CO2) concentrations may help increase crop yields by up to 30%. In “plant factories” (controlled environments for optimized plant growth) CO2 enrichment is one growth-promoting technique. However, plant factories are costly to create and operate. In a typical low-cost greenhouse in a warm climate, is it practical to use CO2 enrichment if combined with evaporation cooling and low ventilation rates?

In this feasibility study, a model of a greenhouse used in eggplant cultivation is developed in Ansys FLUENT 14.0. The boundary conditions are based on on-site measurements including air exchanges, mist spray rates, and continuous temperature and humidity logging.

Scientific Innovation and Relevance

(max 200 words)

The Fluent Discrete Phase Model(DPM) is used to model both the water mist spray and the CO2 injection. The precise modeling of the CO2 flow near the injection pipes is not important to the overall model. Thus, modeling and meshing these many small inlets is avoided by using the DPM model, taking particles of solid CO2 which are set to near-instantly “combust” into CO2 gas, while assuring this does not have a significant effect on the overall thermal model. The model mesh is set finest at the mist spray injectors, where accurately representing the rapid evaporation is of key importance.

The steady state model is used to explore the parameters of mist spray flow rate (full capacity or half), air exchanges (high and low), outdoor air conditions (hot and dry or warm and humid) to find the optimal spray for the given condition. The CO2 distribution is also found for these conditions.

If the low ventilation rates for mist spray evaporation cooling can also permit CO2 enrichment in greenhouses, this may present a low-cost alternative form of “plant factory” which could be of use in warmer climates including in developing countries to increase cultivation yields.

Preliminary Results and Conclusions

(max 200 words)

The test site is using a set mist spray schedule. The objective is to determine the effect of the single mist cooling control regime on the product quality. That is, only one test condition can be done per growing season in each greenhouse. Thus, it is desired to use simulation to test various mist spray parameters to optimize cooling for the climate at the site. Those results can then be tested in the following growing season. Further, the CO2 concentration and distribution can be modelled along with the mist spray flow and cooling effect, and visualized to indicate potential dead zones or accumulations.

At the time of writing this abstract, the mist spray model results (particle paths, air temperatures) are well-matched with on-site measurements on hotter dry days, while less so on humid days. The key uncertainties are the actual natural ventilation rate and the insolation. We are attempting to deduce air exchanges from the change in absolute humidity within the greenhouse given a constant spray rate. Basic air exchange calculations show CO2 enrichment to a significant level should be possible, but the levels and spatial distribution is still being processed.

Main References

(max 200 words)

S.B.Idso, B.A.Kimball, M.G.Anderson, J.R.Mauney. Effects of atmospheric CO2 enrichment on plant growth: the interactive role of air temperature. Agriculture, Ecosystems & Environment, 20(1), pp. 1-10. (1987)

S. Murakamia, Y. Fujimoto, Y. Hayashi, H. Fuchikami, and T. Hattori. Energy cost minimization in plant factories considering weather factors using additive Bayesian networks. Journal of International Council on Electrical Engineering 8(1), pp. 128–135, (2018)

A. Perdigones, J. Garcia, A. Romero, et al. Cooling strategies for greenhouses in summer: Control of fogging by pulse width modulation. Biosystems Engineering 99(4), pp.573-586, (2008)

A. Ganguly and S. Ghosh, A Review of Ventilation and Cooling Technologies in Agricultural Greenhouse Application, Iranica Journal of Energy & Environment 2(1): pp.32-46, (2011)



11:42 - 12:00

Seasonal performance and potential of heat pumps in Catalonia

Thibault Péan, Joaquim Romaní, Elena Fuentes, Jaume Salom

IREC Catalonia Institute for Energy Research, Spain

Aim and Approach

(max 200 words)

Heat pump systems are considered a key element to the decarbonisation of our energy systems, given their ability to supply the thermal loads with (potentially renewable) electricity at a high efficiency. To understand better the impact of a large rollout of heat pumps to provide space heating and domestic hot water services in the residential sector, it is important to analyse in details their performance not only in steady-state conditions, but also on an annual basis, based on specific climates and emission systems, which greatly affect their efficiency. The present study therefore aims at evaluating the seasonal coefficient of performance (SCOP) through four different methods, including simplified calculations, normative methods included in European standards, and detailed annual simulations. These methods are compared for the different climate zones present in Catalonia (Spain), to understand the potential regional differences. Further than the SCOP, the impact of different emission systems is also studied, especially considering the replacement of gas boilers with heat pumps, and evaluating whether the previously installed emitters can be reused with the heat pump, which work at lower supply temperature. Answering these questions will form a basis to support the regional governmental decisions regarding energy plans and sustainable development.

Scientific Innovation and Relevance

(max 200 words)

A thorough comparison of the seasonal performance factor of residential heat pumps is especially relevant, because the different calculation methods may vary from a simple equation correcting the nominal COP, to a more detailed approach based on the number of hours where the heat pump operates annually in a given climate. This study will thus enable to understand the deviations that can be expected in seasonal efficiency, because of the evaluation method, the geographical and climatic disparities, the heat pump control implemented and the final heat emitters. To perform the annual dynamic simulations, a new and detailed dynamic model of air-to-water heat pump has been used.

The question of the refurbishment is also particularly important, if policies are to incite to a large rollout of heat pumps. The most common heating system in Spanish homes consist of a gas boiler supplying water radiators. A boiler can easily be replaced by a heat pump, but changing the radiators for a circuit of fancoils or a radiant floor supposes additional construction works and investments. If the current emission system can be kept and still function correctly at lower temperature, this will reduce the installation costs and encourage a larger heat pump deployment.

Preliminary Results and Conclusions

(max 200 words)

The first results indicate that the regulation of the supply temperature produced by the heat pump, linked to the emission system, has a larger impact on the seasonal efficiency than the climatic differences within Catalonia. With low temperature systems like radiant floor, the SCOP reaches 3.0 to 4.1, while it stays around 2.2 to 3.0 for high temperature systems like radiators. The use of heating curves in supply temperature control, recommended by manufacturers, produce a significant improvement in seasonal efficiency, highlighted by the yearly simulations performed in seven climate zones. The methods from the standard tend to overestimate the seasonal efficiency, as they are based on steady-state performance maps provided by the manufacturers in ideal conditions, while the reality of the building dynamics and the actual control of the heat pump have a slightly negative impact on the performance.

Regarding the replacement of gas boilers with heat pumps without changing the emission system, the first results indicate that such configuration would work in moderate climates. In colder climates, it would cause an important number of hours outside the comfort zone, because of the inherent limits of an emission system designed to work at high temperatures, but operating at lower temperature.

Main References

(max 200 words)

UNE-EN 14825:2018. Acondicionadores de aire, enfriadoras de líquido y bombas de calor con compresor accionado eléctricamente para la calefacción y la refrigeración de locales. Ensayos y clasificación en condiciones de carga parcial y cálculo del rendimiento. Madrid, España, 2018.

Instituto para la Diversificación y Ahorro de la Energía (IDAE), “Prestaciones Medias Estacionales De Las Bombas De Calor Para Producción De Calor En Edificios,” 2007.

Riederer, P., Partenay, V., & Raguideau, O. (2009). Dynamic test method for the determination of the global seasonal performance factor of heat pumps used for heating, cooling and domestic hot water preparation. IBPSA 2009 - International Building Performance Simulation Association 2009, (April), 752–759.

T. Péan, “Heat pump controls to exploit the energy flexibility of building thermal loads,” Universitat Politècnica de Catalunya, 2020.

Péan, T., Costa-Castelló, R., & Salom, J. (2019). Price and carbon-based energy flexibility of residential heating and cooling loads using model predictive control. Sustainable Cities and Society, 50. https://doi.org/10.1016/j.scs.2019.101579

Pospíšil, J., Špiláček, M., & Kudela, L. (2018). Potential of predictive control for improvement of seasonal coefficient of performance of air source heat pump in Central European climate zone. Energy, 154, 415–423. https://doi.org/10.1016/j.energy.2018.04.131



 
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