bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of virtual thermal manikins for thermal comfort numerical studies. Verification and validation
Authors: Croitoru Cristiana , Nastase Ilinca , Bode Florin , Cojocaru Gabriel
Published: August 2019

This study is a part of a larger experimental and numerical campaign intended to evaluate the influence of the turbulence intensity at the inlet of the terminal air distribution systems on the local draft sensation and thermal discomfort of ventilation users. In this paper we present preliminary results of CFD simulations using a realistic model of human body along with an experimental validation. The model is further used in a piston distribution scheme to evaluate the influence of turbulence intensity on the comfort indicators. The recorded velocity, turbulence and temperature fields allowed us to estimate the distributions of DR, PPD and PMV indexes. For the investigated case, the results indicated a direct correlation.
Measurement of Face-touching Frequency in a Simulated Train
Authors: Morita Kentaro , Hashimoto Kaho , Ogata Masayuki , Tsutsumi Hitomi , Tanabe Shin-ichi , Hori Satoshi
Published: August 2019

Contact behavior in a public space influences the risk of contact infection because public spaces have many environmental surfaces contaminated with pathogens. It is useful for risk reduction to examine the factor of infection risk among behaviors. In the present study, a video monitoring survey was conducted in a simulated cabin of a commuter train, we had built, to investigate the relationship between face-touching frequencies and individual attributes. As a result, the average face-touching frequency was 17.8 times per hour. Of all face touches, mucosal contact was 42.2%. Focusing on the sex, the face-touching frequency was significantly higher for the males than for the females. Focusing on the skin condition, the face-touching frequency of those who did not wear makeup was significantly higher than that of those who did. The significant sex differences may depend on the makeup. Focusing on pollution awareness, higher pollution awareness related to lower frequency. Thus, by improving pollution awareness of the environmental surfaces in public spaces, it is possible to reduce effectively face-touching frequency and, hence, infection risk.
Study on Cool Chair equipped with warming function
Authors: Koyama Jun , Doi Yusuke , Ukai Masanari , Nobe Tatsuo
Published: August 2019

Recent air-conditioning systems aim to provide thermal comfort for an unspecified number of residents. However, office workers may perceive the feeling of comfort differently depending on their clothing, metabolic rate, and personal activity level. This may cause difficulties in maintaining an optimal thermal environment. To address this problem, personal air-conditioning has attracted attention, which is highly versatile and can reduce thermal discomfort and provide comfort to all office workers by enabling individual thermal control. Therefore, the authors focused on developing an office chair, the “Cool Chair”, as a chair-type personal air-conditioning system with a cooling function from 2003 to 2016. The authors then added a warming function for year-round operation, creating the “Cool Chair with Warming Function” in 2017. Subjective evaluation results are reported. These experiments using the new chair indicated that the warming function achieves steady state in 30 minutes and the equivalent temperature of the entire body increases by +2°C. In subject experiments, the warming and cooling functions were adjusted according to individual preferences, and the cooling function was used even during winter by some individuals. The authors also confirmed that the feeling of comfort by the subjects improved at both 19°C and 22°C.
Investigations of (local) thermal comfort as a function of radiation asymmetry and vertical air temperature difference
Authors: Beyer Maximilian , Schinke Lars , Alessio Giulia , Seifert Joachim , De Carli Michele
Published: August 2019

The following article describes an extract of the results of experimental investigations on the topic of thermal comfort as a function of radiation asymmetry. The investigations were carried out in the climate chamber [1, 2] of the TU Dresden with the help of subjects. The radiation asymmetry was imprinted by subdividing the climate chamber into two vertically superimposed half-rooms, one of which was heated and the other cooled. In this way, 46 experiments on the heating or cooling ceiling were carried out. The measurement results show an inseparable link between the radiation asymmetry, the vertical air temperature difference and the air velocity. The subject assessed the room climate much more negatively than the ISO 7730 [3] would predict according to the state of the art.
Retracted Article: Historical development of IEQ in Danish dwellings - has energy efficiency requirements inhibited positive IEQ developments?
Authors: Rohde Lasse , Larsen Tine Steen , Jensen Rasmus Lund , Jønsson Kim Trangbæk , Loukou Evangelina
Published: August 2019

This article is an accidental publication. It was accepted by the Guest Editors in charge of the peer-review process without the authors' final consent. The Guest Editors have given their approval for this decision.
Optimal cost-efficiency solution of acoustic treatment for a complex meeting room
Authors: BAILESCU Catalin , IORDACHE Vlad , CATALINA Tiberiu
Published: August 2019

Achieving high acoustic quality in meeting rooms is important for intelligibility therefore several measures are needed especially in reflective high volume rooms. This article tackles the method and the solution to renovate a complex enclosure. The study is divided in multiple stages: development of the 3D room model exported in ODEON acoustic software, validation of the actual condition of the room with measurements, proposing and analysing different acoustic ceiling tiles and finally selecting the optimum solution based on the cost and efficacy in reducing the reverberation time (RT). The measured RT was four times higher (3.45 sec at f=1kHz) than the recommended value (0.9 sec at f=1kHz). The numerical simulation results were in accordance with the experimental measurements with errors of less than 0.2 sec. Using the difference between the RT obtained with the acoustic measures and the optimum RT we were able to calculate an efficiency that was later on compared with the cost of the solution. As a conclusion, due to a large diversity of acoustic ceiling types with different prices and sound absorption coefficients it is important, especially for complex room geometries, to run simulations and to perform a cost-efficiency analysis.
European projects on district energy-renovations and Italian best practices
Authors: Teso Lorenzo , Dalla Mora Tiziano , Romagnoni Piercarlo , Peron Fabio
Published: August 2019

Buildings are the major source of greenhouse gas releases: lowering their energy consumption and emissions is particularly challenging for the existing building stock. This topic was examined at an individual building level in the International Energy Agency’s EBC Annex 56. However, the increasing request of nearly zero energy buildings highlight another important topic: the need of an increase in energy production for satisfying the required amount of renewable energy sources. This task could be solved at the district level for the existing buildings, even if it is a complex issue. This work presents a general introduction on the topic of Urban and Regional Integrated Energy Planning, with a focus on the regional and supraregional process to create and manage energy plans. After the first introductory part, the method is explained through a description of its main phases and the tools used. The subsequent section presents a general overview on the European projects that deal with the problem of district regeneration; the ones that are more related to the topic of this work are considered in a deeper way through tangible applications in Italian cities. The study of already done examples will help in the definition of benefits and drawbacks, with the aim to defining newer and better energy planning procedures.
Radiant wall cooling with pipes arranged in insulation panels attached to facades of existing buildings
Authors: Šimko Martin , Krajčík Michal , Šikula Ondřej
Published: August 2019

Radiant systems are being increasingly used for space heating and cooling of buildings. The contemporary research of radiant systems addresses mainly floor and ceiling structures. Research regarding the possibilities of their incorporation in wall structures is lacking, despite their potential advantages. This study addresses a radiant wall system manufactured according to a patent. The patented design involves panels that consist of pipes arranged in milled channels in thermal insulation. The potential advantage of this system is the fact that the thermally active panels can be attached to the facades of existing buildings as a part of their retrofit. Thereby, only minor interventions on the interior side of the retrofitted buildings are needed. To test and improve the design of the wall system, laboratory measurements and computer simulations were performed on a wall fragment for its operation under summer conditions. The results indicate a significant potential for improvement of the patented design by addressing the imperfections in the contact between pipe and wall. Inserting a metal fin between pipe and wall enhanced the cool distribution within the wall fragment considerably. From the three materials of the metal fin considered, using copper led to highest values of the cooling output, followed by aluminium. For these two metals the effect of increasing the thickness of the fin on the cooling output was small. On the contrary, the fin made of steel was the least efficient in terms of cool distribution. In this case the cooling output was most sensitive to the thickness of the fin.
Homeowners' Decisions Towards Energy Renovations - Critical Stages and Sources of Information
Authors: Ebrahimigharehbaghi Shima , Qian Queena K. , Meijer Frits M. , Visscher Henk J.
Published: August 2019

The European Commission aims to decrease GHG emissions to 80% below 1990 levels by 2050 (EU, 2017). The housing stock has a considerable share that equals to 40% of energy consumption and 36% of emissions in the EU. The current research aims to evaluate the homeowners’ energy renovation decisions on the exterior, interior, and insulation/installation of their house. The householders’ renovation decisions are analyzed with regards to (1) which stages to help/support and (2) what information is essential in the renovation process. Considering the extent of difficulty for private homeowners’ in accessing information and complexity in conducting the renovation, transaction cost (TC) theory is applied in understanding the decisions. The data has been collected through a survey among 3,776 of the Dutch homeowners in 2012. Then, statistical and logistic regression analysis has been conducted to analyze the renovation decisions for two groups of homeowners: renovators and potential renovators. According to the results and the outcomes of this study: (1) For the renovators: (a) the main identified stages in getting help are in carrying out the renovation, determining the costs, and looking for the reliable professional/ contractor, (b) the main identified sources of information are at the maintenance/ installation companies, family/ friends, and via internet; (2) For the potential renovators: (a) the main identified help stages are in determining the costs, looking for a reliable professional and carrying out the renovation/ improvement, (b) the main identified sources of information are via the internet, by a maintenance/ installation companies, and family/ friends. The main difference among the renovators is for insulation/ installation. The most significant stage in getting help for insulation/installation is to find out the most efficient solutions. Similar results have been found for the potential renovators; the only difference was in the order of the influencing factors.
Energy and thermal comfort performance evaluation of PCM ceiling panels for cooling a renovated office room
Authors: Quesada Allerhand José , Berk Kazanci Ongun , Olesen Bjarne W.
Published: August 2019

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.
Cost optimal energy performance renovation measures in a municipal service building in a cold climate
Authors: Jokisalo Juha , Sankelo Paula , Vinha Juha , Sirén Kai , Kosonen Risto
Published: August 2019

The energy saving potential of existing buildings is significant compared to new buildings in the EU region. To reduce significantly the CO2 emissions of buildings, energy efficiency of old buildings need to be improved. Aim of this study is to determine cost-optimal solutions for energy renovation and renewable energy production systems for an old existing service building. The example building of this study is a residence for elderly people, which was built in 1955 and located in Finland. This study was carried out by a dynamic building simulation tool IDA-ICE and multi objective optimization tool MOBO. The cost-optimal renovation concepts were determined from over 2.6 billion renovation measure combinations to minimize both target energy consumption and life-cycle costs over 20 years. The results show that air-to-water heat pump is more cost effective heating system for the studied building than district heating from the building owner point of view. Improving thermal insulation level of the external walls from the original level is not the most cost-effective option to improve the energy efficiency of the building. Instead of that, for example, installation of PV and solar thermal systems are recommended in all the cost-optimal solutions regardless of the target energy consumption level.
A Decision-Making Algorithm for Energo-Economic Sustainability and Efficiency in Buildings: A Case Study in Turkey
Authors: Tekin Derya Kışla , Çolak Levent , Kılkış Birol
Published: August 2019

Today, sustainability and energy efficiency are of prime importance in satisfaction of thermal and electrical loads of buildings. In this study, innovative hybrid solutions alternative to conventional HVAC systems are investigated. Objective of study is to minimize the payback period and CO2 emissions are main objectives. For conventional HVAC systems two sources of energy, namely natural gas and electricity were considered as the base line. Energy sources for the innovative methods were considered to be solar energy, ground heat and waste heat. Conventional system was considered to be a backup system when innovative energy resources are insufficient. Hourly heating, cooling and electrical power loads of Eser Green Building, which already has LEED Platinum certificate were used for the case study, which aims to further improve the energy and exergy efficiency. In the new algorithm being developed, all power conversion systems were defined in a simple input- output transfer function format. A decision-making algorithm and an ExcelTM-based simulation program were developed and tried with Eser Green Building input data for different renewable energy source and system combination conventional systems, energy sources, and equipment in term of investment, operation and total cost, payback period, and carbon dioxide emission values. Payback period of Eser green building is 11,8 years and for two hybrid systems are 13,2 years and 9,2 years, respectively. Carbon dioxide emissions by hybrid systems under the same load conditions were found to be 488 kgCO2/h and 592 kgCO2/h for approaches, respectively.
A framework for the technical evaluation of residential buildings’ energy retrofit
Authors: Belleri Annamaria , Dipasquale Chiara , Adami Jennifer
Published: August 2019

Despite a wide range of energy-efficient technologies, financial products and public incentives are already available, the private as well as the public sector are struggling to invest in energy efficient solutions for buildings. The primary barriers are the high initial cost and the uncertain payback period of the energy refurbishment. Allowing for different scenario testing and considering interactions among different building energy systems, building energy simulation tools can help investors overcoming such barriers by offering support to the technical planning of energy refurbishment kits through quantitative information rather than qualitative. The energy performance and comfort of three reference multifamily residential buildings typologies were evaluated considering three envelope retrofitting performance levels (high-medium-low insulated and airtight) and different heating and domestic hot water systems (heat pump, boiler, district heating). The tested envelope retrofitting performance levels allow for heating need reduction between 50% and 90% compared to the reference case. The active cooling system is not accounted for and building energy simulations outputs include thermal comfort evaluation and overheating risk assessment during the summer season. The potential of photovoltaic system combined with heat pump is evaluated in the three reference cases leading to up to 30% of load coverage.
How to compare energy performance requirements of Japanese and European office buildings
Authors: Ahmed Kaiser , Yoon Gyuyoung , Ukai Makiko , Kurnitski Jarek
Published: August 2019

This study applied the normalisation method that enabled to compare the energy performance of buildings from European and Japanese climates. A reference office building was simulated with national input data and weather file in order to estimate the thermal conductance of building model and heating degree-days for a reference climate. Based on simulated results, economic insulation thickness and thermal transmittance of windows for all climates were determined. A reference office building corresponding to Japanese ZEB Ready performance was moved with this method to Estonian and French climates. The results compared to national NZEB requirements and EC NZEB Nordic and Oceanic recommendations. It was found that the Japanese ZEB Ready building configuration with air source heat pump was very close to EC NZEB recommendations. However, in the case of district heating and gas-boiler heat sources, it was needed to improve Japanese ZEB Ready building configuration in order to meet EC NZEB recommendations. Estonian NZEB requirement met EC recommendation with both heat sources, but French NZEB requirement was much less ambitious.
Numerical study on heat blocking efficiency of non-recirculating air curtain and its optimal discharge velocity
Authors: Lee Sihwan
Published: August 2019

From the point of view to reduce energy consumption, door open while air conditioner running on buildings have a problem. To solve the problem, many facilities for entrance with vestibule, revolving door, and air curtain are utilized. Among the facilities, the air curtain cuts off the indoor and outdoor air by discharging the wide air surrounding the opening, thereby preventing the heat loss from the indoor. The purpose of this study is to evaluate the heat blocking efficiency of non-recirculating air curtain and to evaluate its optimal discharge velocity. To achieve this goal, the infiltration rate across the single-side opening were investigated with air temperature differences between areas by transient CFD simulation and the results were compared with the steady-state calculation method. In addition, to evaluate the heat blocking efficiency of non-recirculating air curtain, the calculation model was set up and several cases with discharge velocity were compared. The results show that the discharged air from the air curtain causes a deflection from the high temperature area to the low temperature area, and the deflection decreases with increasing the discharge air velocity. In this study, the safety factor for deflection modulus of the non-recirculating air curtain was calculated 2.75.
The Influence on Daylight and Energy Consumption of Expanded Metal Mesh Applied on Building Façades
Authors: Yaw-Shyan TSAY , Chih-Hung YANG
Published: August 2019

Expanded metal mesh has become widely used as a shading element in the façade of many buildings in recent years, and its energy saving performance has been evaluated in tropical/subtropical countries. However, expanded metal mesh reduces solar radiation while also reducing the natural daylight entering the building. This study’s objective is to assess the impact of expanded metal mesh on building energy consumption and natural daylighting.

The daylight effects on visual comfort and energy consumption of an office building located in Tainan, Taiwan were studied via building simulation program DIVA. Parameters including window to wall ratios (WWR), perforation rate expanded metal mesh, and glazing of window glass were studied, and a daylight standard of LEED rating system was used for evaluation.

The results showed that when the office building with large WWR and less glazing, the expanded metal mesh performed a better energy saving effect. For an office building with 50% WWR, the laminated clear glass and expanded metal mesh with 21% perforation rate were suggested to be the best design solution for meeting the LEED daylight standard and the lowest energy consumption.
Impact of IPPC Scenarios on indoor environment quality of historic buildings
Authors: Weyr Jan , Kalný Richard , Hirš Jiří
Published: August 2019

Ensuring proper indoor environment quality in buildings with historic value or buildings located in historic centres of cities is not an easy task. These buildings are frequently listed in historic preservation lists; thus, the amount of possible refurbishment methods is significantly limited due to increased protection. This article deals with comprehensive analysis of internal microclimate of a multi-purpose building located in the historic centre of Prague during summer period. Possible refurbishment methods permitted by the National Heritage Institute are analysed and compared using building energy performance simulation tool BSim in order to achieve proper working conditions in offices in the building. Structural and technical modifications are proposed in order to optimize the amount of solar heat gains leading to reduction of overheating and increase of energy efficiency. Furthermore, two global warming projections from the Fourth Assessment Report of Intergovernmental Panel on Climate Change are applied to the current weather data to examine the impact of the global climate change on the building. As expected, the cooling demand increases with the climate change scenarios presenting more difficult challenges to maintain the indoor environment quality within the limitations given by the legislation.
Indoor Climate in Jesuit Church of Holy Name of Jesus in Telc
Authors: Hnilica Ondřej , Bichlmair Stefan , Plášek Josef
Published: August 2019

The Jesuit church of Holy Name of Jesus from year 1667 is integral part of main square of Telc with Baroque houses from 17th century listed in UNESCO World Heritage Site since 1992. The natural indoor climate of Jesuit church is heated only in occupied pews during liturgical ceremony in winter season. The hygrothermal analysis of natural indoor climate in Jesuit church is performed by preventive conservation method of Target range and Historical climate in period from April 2017 to October 2018. The obtained result shows appropriate indoor climate for preventive conservation of historical furniture (main altar, lateral chapels, pulpit, confessional, organ, paintings), holy remains and valuable artefacts for liturgical ceremony. This hygrothermal analysis of natural indoor climate in Jesuit church supports current state of local heating in occupied pews during liturgical ceremony in winter season.
Passive generation from a novel thermoelectric energy harvesting system model integrated with phase change material
Authors: Byon Yoo-Suk , Lim Hansol , Kang Yong-Kwon , Yoon Soo-Yeol , Jeong Jae-Weon
Published: August 2019

The purpose of this research is to evaluate the performance of a novel model that incorporates a thermoelectric generator (TEG) and phase change material (PCM). The proposed model passively generates electricity using waste heat that accumulates at exterior wall surfaces. The main generator is a TEG. To maintain the temperature difference between the two sides of the TEG, PCM is located at its cold side—thus converging the heat transferred into latent heat. The proposed passive generation system is formed into a TEG-PCM block. The block can be stacked to form a wall or inserted into any part of a building that faces the sun. The experiment setup is based on a constant temperature method. The wall temperature profile is set according to solar radiation, convection, and radiative heat transfer. To replicate daily wall temperatures during the experiment, a heat plate is used to match a wall temperature profile. Step control was used for the heating plate. The resulting data shows the average temperature difference between the hot and cold sides of the TEG to be 10-20°C. The peak generated electricity was 0.08 W for a single module.
Efficient Operation of Heat Source using High-temperature Chilled Water in an Advanced Office Building
Authors: Suzuki Yuya , Imazu Misa , Shinoda Jun , Furukawa Ryoya , Araki Yumiko , Tanabe Shin-ichi , Fujino Kenji , Hatori Daisuke , Hirasuga Nobuhiro , Kato Shun , Sasahara Shiori , Iwata Hiroki
Published: August 2019

In recent years, energy conservation has become a major focus in the industrial sector. Many office buildings in Japan achieve energy savings by introducing highly efficient equipment and systems, such as high-temperature cooling water (14 °C), which increases heat source efficiency. However, such equipment requires adjustments to increase operational efficiency. In this case study, the efficiency of equipment using high-temperature cooling water was further improved through operation control optimization. The energy efficiency before and after the improvement was compared. The target building has chilled and hot water supplied to each floor from district heating and high-temperature chilled water supplied from cooling chillers on the rooftop. The energy consumption of two floors was evaluated: a subjective floor with equipment using high-temperature cooling water installed, and a common floor with a conventional system. After on-site verification, changes were made to the operation control of the cooling towers, condenser pumps, primary pumps, secondary pumps, and air handling units. As a result, the coefficient of performance of the water-cooled chiller and the whole system improved by 0.40 and 0.45, respectively. The flow rate of the air conditioning equipment using high-temperature cooling water decreased while maintaining an equivalent amount of heat extraction. In conclusion, the efficiency of the equipment was further improved by operation control optimization.
Measurement Analysis and Evaluation of Desiccant Air Handling Units with Various Heat Source
Authors: Sasamoto Taro , Ukai Makiko
Published: August 2019

In hot and humid summer as in Japan, dehumidification is important process for air conditioning. Desiccant air handling unit is one of the major system for dehumidification in which absorbent or sorbent absorbs moisture in the air and hot heat source is required in order to regenerate them. Desiccant air handling unit is becoming common system, however there is little information about actual operation results and evaluation based on the measurement results. This study provides actual data set and benchmarks which are useful for designing desiccant air handling unit and to evaluate energy performance of various desiccant air handling systems. Measurement results show that coefficient of performance of desiccant air handling unit itself is around 0.7 in summer with polymer sorbent. In addition, the coefficient of performance of desiccant air handling system is defined and the value depends on the coefficient of performance of heat source and the distribution between chilled water and hot water.
Calibration of a building energy model using operation conditions derived from monitoring
Authors: Tanasa Cristina , Becchio Cristina , Corgnati Stefano Paoloc , Stoian Valeriu , Dan Daniel
Published: August 2019

Building energy modelling and simulations play an important role in the design of energy efficient buildings but also in post-construction phases for commissioning, operation and optimization. With the use of data from monitoring systems related to the operation conditions of a building, calibrated simulations can be performed that accurately follow the real energy performance of a building. This paper present a procedure to achieve a calibrated building energy model simulation using monitoring data. The aim of the study is to verify/validate the results of the building energy model simulation against measured data. The study is based on an existing highly energy efficient building, which is continuously monitored in terms of energy consumptions and environmental parameters for several years now. The performance of the building energy model was assessed using statistical indices. The monthly total energy consumption comparison between simulated and measured shows that the building energy model managed to predict very closely the measured values. The accuracy of the building energy model in predicting air temperature was assessed as well.
Influence of Building Air Tightness on Energy Consumption of Ventilation System in Nearly Zero Energy Residential Buildings
Authors: Liu Wei , Yu Zhen , Wu Jianlin , Li Huai , Gao Caifeng , Gong Hongwei
Published: August 2019

Building air tightness increased quickly in recent years as nearly zero energy buildings concept gradually drawn more attentions from the industry. Ventilation system plays an important role for the indoor air quality control in residential buildings with good air tightness. The energy consumption of the ventilation system is a significant part of the overall energy consumption of low energy residential building. The influence of the building air tightness on the energy consumption of ventilation system was not addressed sufficiently in previous studies. This paper analyses the quantitative relations between building air tightness, energy recovery efficiency and ventilation system control strategy. A mathematical model of the heating and cooling energy consumption in residential buildings is proposed, which takes building air tightness, energy recovery efficiency and control strategy of ventilation system as major input parameters. Equivalent COP of ventilation energy recovery system is proposed as an energy efficiency index of the ventilation system. It can be used as a criterion to decide the optimal design parameters of nearly zero residential buildings in different climate conditions.
Annual performance analysis of heat emission in radiator and underfloor heating systems in the European reference room.
Authors: Võsa Karl-Villem , Ferrantelli Andrea , Kurnitski Jarek
Published: August 2019

In this paper, we investigate the energy usage and emission efficiency of radiator and underfloor heating systems coupled with ON/OFF and PI controls, by performing annual simulations with the IDA ICE software package. Results from measurements carried out in early 2018 at the nZEB test facility near the Tallinn University of Technology are used to calibrate validated emitter and controller models. The calibrated models are then used to assess the energy performance of the systems in a simulation spanning the whole year, using climate data for Strasbourg in the European reference room. The annual simulation is conducted in a specific room with fixed geometry and boundary conditions.

As a novelty value of the present study, we impose a non-standard control strategy based on maintaining a specified operative temperature within the room. A single-valued performance indicator, in the form of an increased air temperature set-point, is accordingly obtained for each emitter configuration to be used in further calculations of hourly, monthly or annual heating energy usage. Such a temperature increment accounts for imperfect control, air stratification within the room and the additional temperature increase that is required for achieving a desired operative temperature.
Towards zero energy hospital buildings: a polyclinic building as case study.
Authors: Dainese Enrico , Walker Shalika , Maassen Wim , Zeiler Wim
Published: August 2019

The need for (nearly) Zero Energy Buildings (nZEBs) becomes increasingly important due to climate change and increasing energy prices. Considering that, on average the existing hospitals use 3.5 times more energy than the nZEB requirement, reaching zero energy a very challenging task. However, monitoring hospitals’ energy flows together with a holistic view on building functions and occupancy can contribute to achieving potential energy savings, which is lacking in the current hospital buildings.

Therefore, in this study, the energy saving potentials of a polyclinic building of a hospital in the Netherlands was investigated through a holistic inspection of the building and its occupancy. The analysis is performed in order to investigate the building characteristics, energy supply and demand. It was found that the number of people present was considerably lower than the full capacity, with 30% average occupancy in the medical facilities and 70% for the administrative areas. The air supply of the current ventilation system was found to be constant irrespective of the number of people present in these rooms. Furthermore, a discrepancy of 30- 50% was found between designed and installed lighting systems. The analysis of the polyclinic showed possible energy-saving measures with controlled ventilation rates and lighting according to the occupancy.
Parameters that influence the probability on lower-than-expected energy savings - a pre- and post renovation energy consumption analysis of 90,000 renovated houses in the Netherlands
Authors: van den Brom Paula , Meijer Arjen , Visscher Henk
Published: August 2019

Thermal renovations are considered to be an effective measure to reduce residential energy consumption. However, they often result in lower-than-expected energy savings. In this paper, we investigate some parameters that influence the probability on lower-than-expected energy savings. We do this by comparing actual pre- and post-renovation energy consumption of 90,000 houses in the Netherlands. The results of this study confirm that the effect of the parameters differ per renovation measure. For every renovation measure, the energy performance gap post renovation plays a significant role. This implies that the use of actual energy consumption data to determine the potential energy savings could therefore help to reduce the number of renovations resulting in lower-than-expected energy savings. Also, the energy efficiency state of the building pre-renovation plays an important role. One should take into account that renovations of energy inefficient buildings more frequently result in lower-than-expected energy savings than renovations of relatively energy efficient buildings. For the type of house we found that multifamily houses more often result in lower than expected savings when building installations are improved, while single-family houses renovations more frequently result in lower energy savings than expected when the building envelope insulation is improved. These insights can contribute to the decision making process whether or not to take a certain renovation measures, they can also help to manage expectations on housing stock level and individual building level.
Green Hybrid Energy for Office Building
Authors: Filote Constantin , Felseghi Raluca-Andreea , Cârlea Filip , Raţă Mihai , Martiş Claudia Steluţa , Lavric Alexandru , Fodorean Daniel , Răboacă Maria Simona
Published: August 2019

This contribution presents a comparative study of operating a green energy hybrid system to sustain the power production mix of an office building. For this purpose, two scenarios of a hydrogen storage system (S1) and battery energy storage (S2) to sustain solar and wind energy inlets were compared from a technical, environmental and financial perspectives. S1 - hydrogen technology system was found to be more performing than S2 - battery technology in terms of energy efficiency, as well as CO2 emissions and initial costs.
Establish high-resolution hourly weather data for simulating building energy consumption in different regions
Authors: Lin Feng-Yi , Hwang Ruey-Lung , Lin Tzu-Ping
Published: August 2019

Due to the various local weather conditions in different regions of the city, the demand for air conditioning (AC) of housing is different, too. It happened occasionally to underestimate the energy consumption of AC in urban areas, because of using suburban/rural weather station data for building energy simulation. This study set up 34 automatic weather stations in the urban area of Tainan City, Taiwan for a year-round collection of local temperature and relative humidity data. Those weather measurement, the GIS information of a buffer zone and multiple regression analysis were used to establish the relationship between the weather factors, needed for the morphing approach, and the parameters of landscape use and cover. The buffer zone is an area of 1000×1000 m2 around the measured point, and is divided to two layers with upwind and downwind parts. Local hourly weather-year files for a whole of the city with a resolution of 200×200 m2 were generated by the morphing approach. With the different local hourly weather-year files, the AC-required hours and energy consumption from May to October for a typical residential with hybrid ventilation mode was obtained by using the EnergyPlus. And the cumulative UHI of each grid between May and October is calculated by taking the average of the five lowest temperatures as the reference value. The result shows that the number of AC hours of residential will increase by 10%, and the energy consumption increase from 1000 kWh to 2500 kWh, when long-term UHI intensity increases from 2000 °C-hour to 9000 °C-hour.
CO2-based grey-box model to estimate airflow rate and room occupancy
Authors: Wolf Sebastian , Justo Alonso Maria , Calì Davide , Krogstie John , Martin Mathisen Hans , Madsen Henrik
Published: August 2019

In the existing building stock, heating, cooling and ventilation often run on fixed schedules assuming maximal occupancy. However, fitting the control of the HVAC system to the building’s real demand offers large potential for energy savings over the status quo. Building occupants’ presence as well as mechanically supplied and infiltrated airflow rates provide information that enables to define tailored strategies for demand-controlled ventilation. Hence, real-time estimations of these quantities are a valuable input to demand-controlled built environments. In this work, the use of stochastic differential equations (SDE) to estimate the room occupancy, infiltration air-rate and ventilation air-rate is investigated. In particular, a grey-box model based on a carbon dioxide (CO2) mass balance equation is presented. The model combines knowledge about the physical system with statistical, data-driven parameter estimation. Furthermore, the proposed model contains uncertainty parameters. This is in contrast to purely deterministic models based on ordinary differential equations, where uncertainty is usually disregarded. The suggested model has been tested in a naturally ventilated and in a mechanically ventilated environment; the performance in these two cases has been compared. We show that the ability to address measurement errors and non-homogeneous conditions in the room air implies that the suggested SDE-based grey-box approach is suitable in the context of demand-controlled ventilation.
Sensitivity analysis of peak and annual space cooling load at simplified office dynamic building model
Authors: Zeferina Vasco , Birch Christina , Edwards Rodger , Wood Ruth
Published: August 2019

The focused investigation of building design is necessary to understand and quantify the implication of different design parameters on their energy performance. The design of future buildings is a major challenge, as current designs may be inappropriate in a future with global warming due to climate change impacts. In addition this understanding is necessary to be able to predict timing and profile of future energy demand, which is crucial for the long-term planning of energy infrastructures – particularly electricity. In this paper, the Morris Elementary Effects method is used as a screening method, to identify the key parameters of the design and operation of office buildings that affect the estimation of space cooling peak load and annual energy demand. Internal heat gains, cooling set-point and ventilation rates are identified as the parameters with larger implications for both annual and peak space cooling demand. In future climate scenarios, the magnitude of change of annual space cooling demand is significantly (around five times) larger than the change in the peak demand. Asides from the potential increase of space cooling demand in future scenarios, the sensitivity of the space cooling demand relative to the change in design parameters is potentially much larger.
How will climate alter efficiency objectives? Simulated impact of using recent versus historic european weather data for the cost-optimal design of nearly zero energy buildings (NZEBs)
Authors: D’Agostino Delia , Parker Danny S.
Published: August 2019

Achieving “nearly zero energy buildings” (NZEB) has been established as a vital objective over the next decade within the European Union (EU) [1,2]. Previous work has shown that a series of very cost effective thermal efficiency measures, equipment, appliance and renewable energy choices are available across climates to reach the NZEB objective. Resulting detailed energy and economic optimization findings have been obtained and published [3,4]. One area that has just begun to be explored, however, is how selection of weather files and their application against coming climate change can influence outcomes from energy optimization procedures.
Assessing the reliability of Turkish building energy performance tool (BEP-TR2) by case tests
Authors: Ulukavak Harputlugil Gulsu , Yilmazoglu M. Zeki , Unlu Gokhan
Published: August 2019

This paper aims to draw a general picture of the simplified software for calculation building energy performance based on Turkish Regulations called BEP-tr.v2, which was released at the end of 2017. Even the tool has a simplified calculation methodology, the discussion in this paper is going to be focused on assessing the accuracy of the tool by test cases. The assessing procedure for the tool has two steps. In the first step, box type cases are analyzed, and the results are compared with the results of a detailed energy simulation tool (BES) to perceive the percentage of deviations. In the second step, a current building is selected to use as a test case. The model results are compared with the real consumptions of the building to see the convergence rate of the tool (Bep-TR2). The results showed that the net energy calculation procedure of the methodology needs to be improved.
Statistical analysis of air conditioning peak loads of multiple dwellings
Authors: Ono Tetsushi , Hagishima Aya , Tanimoto Jun , Ahmad Zaki Sheikh , Aqilah Hisham Naja
Published: August 2019

Evaluation of the aggregated air-conditioning load of multiple dwellings is important for demand response through the optimum control of numerous air-conditioners (A/Cs), for development of smart-city or smart-community technologies. However, past studies have mainly focused on the characteristics of A/C load in a single household. With this background, the authors conducted statistical analysis of time-series data for A/C electricity consumption in 489 dwellings in Osaka, Japan, and 20 dwellings in Kuala Lumpur, Malaysia to grasp the feature of aggregated A/C load of multiple dwellings. The findings of this analysis are followings: 1) the aggregated A/C load peak per dwelling decreased by almost 50% as the number of dwellings increased from 1 to 10, due to the offset of the diverse time-patterns of A/C load. 2) The occurrence of the top 2.5% A/C load shows strong time and date dependency for an A/C load aggregated by many dwellings:
Inclusion of window opening habits in a window model based on activity and occupancy patterns
Authors: Verbruggen Silke , Delghust Marc , Laverge Jelle , Janssens Arnold
Published: August 2019

The occupants’ window opening behaviour can have a substantial influence on the indoor climate and the energy use in low energy dwellings. In literature, most window opening models are based on outdoor and/or indoor climate variables. However a study of Verbruggen et al. [1] revealed that these models are not able to predict the window opening behaviour accurately in wintertime, which may be attributed to the presence of window opening habits. The occupants perform the habits not according to a fixed time step but rather to the performance of a reoccurring activity or an occupancy change. Therefore, a window opening model is generated based on the occupancy and activity patterns of the inhabitants. The model links certain behaviours to specific activities or moments in an occupant’s day without relating it to an exact time-step or specific weather conditions. Data on these habits and the links with occupancy are acquired from a survey conducted in a NZEB case-study project in Belgium. This paper includes the results of the habit-survey and explains how the window use model based on habits is generated. Based on the answers from the survey the window use in bedrooms and bathrooms could be fully defined for 93% of the households, only in the living room no complete window use profile could be defined. The developed model is able to predict the window use in a more realistic way compared to weather-models, with window opening actions linked to specific moments in the occupant’s day.