bluuebunny/crossref_metadata_2025_split huggingface dataset:
The impact of internal gains on thermal stratification for public buildings
Authors: Laghmich Nisrine , Romani Zaid , Lapisa Remon , Draoui Abdeslam 
Published: October 2019

Abstract
The indoor temperature in public buildings varies according to its internal loads scenario. In fact, this building typology in temperate climates is generally non-air conditioned and naturally ventilated. In order to improve indoor thermal conditions with appropriate solutions, it is necessary to study the vertical temperature profile. The main objective of this study is to show the impact of thermal stratification on thermal comfort of public buildings. The thermo-airodynamic modeling using TRNSYS(C) and CONTAM(C) have been performed in this numerical simulation study. The indoor air volume is vertically subdivided into several levels to evaluate the evolution of temperature profile taking into account the different inside-outside air exchange and air coupling between sub-zones. This study is performed in the city of Morocco that represents Mediterranean climate region with a moderate temperature. The effect of several parameters, such as indoor occupation pattern, internal lighting, sub-zones air exchange and vertical thermal stratification are studied. Numerical simulation results show that thermal stratification of buildings affects the occupant’s comfort level
Understanding indoor environmental conditions and occupant’s responses in houses of older people
Authors: Soebarto Veronica , Williamson Terence , Carre Andrew , Arakawa Martins Larissa 
Published: October 2019

Abstract
In Australia, the vast majority of older people, those aged 65 years and over, want to live at their own homes for as long as possible. Older people are, however, vulnerable to extreme conditions, hot or cold, and therefore it is crucial to ensure that the home’s indoor environmental conditions are conducive to their health and well-being. The first step to do this is by understanding the existing conditions in homes of older people so that appropriate steps for improvements can be taken. This paper presents an on-going study to understand the indoor environmental conditions and occupant’s responses in homes of older people in South Australia. The study is conducted using a robust indoor environmental monitoring system that is integrated with a user-friendly occupant survey system using an electronic tablet, allowing the occupants to reflect on their “right here right now” experience over different seasons in a year. The paper discusses the development of this integrated system and reports some preliminary data. Preliminary results showing the associations between measured environmental data, such as dry bulb temperature, radiant temperature, air velocity, and CO2 level, and thermal sensation, comfort, perception of indoor quality and self-reported health/well-being will also be presented.
A personal visual comfort model: predict individual’s visual comfort using occupant eye pupil size and machine learning
Authors: Cen Lingkai , Choi Joon-Ho , Yao Xiaomeng , Gil Yolanda , Narayanan Shrikanth , Pentz Maryann 
Published: October 2019

Abstract
Lighting, as a significant component of indoor environmental quality, was found to be a primary contributor to deficient indoor environments in today’s workplace. This resulted from the fact that current guidelines are derived from empirical values and neglect the prevalence of computer-based tasks in current offices. A personal visual comfort model was designed to predict the degree of an individual’s visual comfort, as a way of evaluating the indoor lighting of the environment. Development of the model relied on experimental data, including individual eye pupil sizes, visual sensations, and visual satisfaction in response to various illuminance levels used for tests of six human subjects. The results showed that (1) A personal comfort model was needed, (2) the personal comfort model produced a median accuracy of 0.7086 for visual sensation and 0.65467 for visual satisfaction for all subjects; (3) To develop a prediction model for the sample group, the Support Vector Machine algorithm, outperformed the Logistic Regression and the Gaussian Naïve Bayes in terms of prediction accuracy. It was concluded that a personal visual comfort model can use a building’s occupant’s eye pupil size to generate an accurate prediction of that occupant’s visual sensations and visual satisfaction that can, therefore, be applied with lighting control to improve the indoor environment and energy use in that building.
Building Energy and IAQ improvement by Coupled Model
Authors: Heibati Seyedmohammadreza , Maref Wahid , Saber Hamed 
Published: October 2019

Abstract
The building performances are related to Energy Efficiency and Indoor Air Quality (IAQ). Modeling is one of the best accurate tools for measuring the building performance. Nowadays, Energy Efficiency and IAQ are modeled individually for buildings. Improvement strategies in both areas are analyzed separately. The fundamental problem in Energy and IAQ modeling is related to interaction to each other. This problem makes the modeling results unrealistic to the building performance solutions. To avoid this problem, in this current research, Energy and IAQ models are coupled simultaneously as a new co-simulation method. EnergyPlus and CONTAM are used as Energy and IAQ models, respectively. With the co-simulation method, these two models are coupled together. The method is based on the exchange of control variables between both models dynamically and simultaneously. As a result, the exchanges of temperature and air flow variables are corrected. The verification of the new model is based on the comparison of the simulation and analytical results of temperature and air flow variables. In the next step, this new coupling-co-simulation method for a townhouse building is done in two cases: a leaky and a tight building envelopes. Both cases are compared in two types of ventilation systems: infiltration only, and exhaust only. At this point, the simulated air change rates, gas energy use, and particles concentrations are compared for each case. Finally, the necessity of the accuracy of this new method is concluded.
Field measurement on the particle concentrations and exposures in five residential buildings in Korea
Authors: Kang Kyungmo , Kim Hyungkeun , Gyu Lee Yun , Kim Taeyeon 
Published: October 2019

Abstract
This study measured five apartments in the Daejeon. There is higher fluctuation for ambient air particle conditions. The average PN (particle number) concentrations was 5.2x108/m3. There are differences between five sites because of fluctuation for ambient air conditions. Particle concentration has different each occupant schedule. I/O ratios were different by occupancy schedules. Indoor particles exceeded 0.7 μm was significant emitted indoor activities. This result comes from two reasons. 1) Penetration by envelopes. 2) Indoor sources by occupants’ activities. PN decay rate (a+k) were 0.49-4.29 h−1 during indoor peak events. Total emitted particles (σ) was 0.0136.15 x 1013 particles per events. The cooking generated PN were wide range because of different event conditions. The ventilation rate is not enough to remove particles.
Development of numerical heat and mass transfer model for predicting total heat exchange performance in Energy Recovery Ventilator
Authors: Sotokawa H , Kameishi K , Chung J , Yoo S , Ito K 
Published: October 2019

Abstract
An energy recovery ventilator (ERV) is a widely used equipment that can recover sensible and latent heat. To improve its performance, it is essential to understand the heat and moisture transfer mechanism in the ERV. Against this background, overarching objectives of this study are to develop mathematical/numerical models for predicting and clarifying the hygro-thermal (i.e. heat and moisture) transfer mechanism in the heat exchange element of the ERV in terms of (i) simplified model for sensitivity analysis, and (ii) comprehensive model to integrate hygro-thermal transfer equations with computational fluid dynamics (CFD) analysis. Toward this end, we conducted fundamental experiments to measure temperature, humidity, and enthalpy exchange efficiencies in the scale-down ERV unit model, and then, numerical analyses were conducted according to the experimental scenario. As results of this study, we confirmed the reasonable prediction accuracy of our proposed numerical models for predicting total heat exchange performances.
RELaTED, decentralized & renewable Ultra Low Temperature District Heating, concept conversion from traditional district heating
Authors: Lumbreras Mugaguren Mikel , Garay Martínez Roberto , Sánchez Zabala Víctor 
Published: October 2019

Abstract
District Heating (DH) are a very efficient system for heating in urban areas and they are considered as key elements for the de-carbonization of the European Cities. High performance levels and low operational energy costs are part of the identity of these heating networks. The reduction of supply-line temperatures allows the possibility to introduce new low-grade and renewable source energy production, reducing dependence on fossil fuel-based energy plants. Moreover, heat-losses in distribution pipelines are also reduced, since the gradient temperature between supply line and ambient temperature is reduced. Operation of decentralized & Ultra Low Temperature (ULT) systems may adapt for the introduction of weather-dependent, distributed heat sources such as solar systems. Furthermore, although very dependent on local availability, waste heat streams from commercial and industrial installations are also considered because of the stability of heat supply all year round, resulting in minimally carbon intensive processes. Regarding building features, the reduced heat load derived from the transition from current buildings to Nearly Zero Energy Buildings (NZEB), RELaTED allows for the novel concept called prosumer, where buildings can deliver energy to the grid from decentralized energy sources installed in the building. In RELaTED, different subsystems are being developed by different industrial partners, to prove their efficiency in 4 real demonstration sites: Tartu (Estonia), Belgrade (Serbia), Vinge (Denmark) and Iurreta (Spain). A 3-FS (3-Function Scheme) DH substation that permits buildings to become prosumers. Two types of solar collectors, one is an all polymeric glazed collector and the second one is an unglazed collector, both as components of Building Integrated Large Solar Thermal Systems (BILSTS) solar loop. Finally, a reversible and high efficiency heat pump for domestic hot water is being developed. In this paper, an approach to ULT concept is studied, including transitory phases of the conversion.
Triple function substation and high-efficiency micro booster heat pump for Ultra Low Temperature District Heating
Authors: Lumbreras Mugaguren Mikel , Garay Martínez Roberto , Sánchez Zabala Víctor , Korsholm Østergaard Kasper , Caramaschi Matteo 
Published: October 2019

Abstract
District-Heating (DH) covers around the 9% of the total heat demand in the EU, with a proven highperformance levels and low operational costs. DH may suffer adaptations in order to maintain competitiveness with individual heating systems. The most important one is the reduction of supply temperatures up to 50°C, emerging the concept of Ultra Low Temperature (ULT) DH. ULT DH allows the transmission and distribution heat losses minimization, since heat losses are proportional to the temperature-gradient between supply line the ambient, increasing overall system performance. Furthermore, enables the integration of low-grade energy sources with low marginal costs, such as solar thermal energy or waste heat from industrial and commercial buildings. This study presents the combination of a novel 3 function-scheme (3FS) substation and a micro booster heat pump for domestic hot water. The novel design of the substation allows different operation modes between the grid and the building according to the temperature level and demand range every moment. Regarding the microbooster, this unit is used directly to lift the temperature of the domestic hot water (DHW), so that risk of legionella is avoided and that the required comfort temperature is reached. Preliminary test for the energy performance of the booster heat pump was measured on serially produced units according to tapping profiles and methodologies of standard EN16147. DHW coefficients of performance of 5.2 and 8.5 were measured for heat source supply temperatures respectively of 25 and 40 °C and return temperatures of 22 and 30 °C. This paper explores the possible operational modes of a 3FS in combination with a Building Integrated Solar Thermal System (BISTS) and a Microbooster heat pump.
Heat analysis for energy management in neighbourhoods: case study of a large housing cooperative in Norway
Authors: Sørensen Å L , Lindberg K B , Walnum H T , Sartori I , Aakenes U R , Andresen I 
Published: October 2019

Abstract
As a basis for energy management in apartment blocks, this paper characterises heat use in a large housing cooperative in Norway, with in total 1,058 apartments. Heat measurements with hourly resolution are available from 20 heating substations. Average specific heat delivery is 139 kWh per heated floor area. A linear regression model is described, modelling specific heat delivered to the apartments. Models are also used for separating heat to domestic hot water (DHW) from the total heat delivery, with a modelled DHW heat delivery of 34 kWh/m2. Daily heat load profiles are presented, for delivered heat during weekdays and holidays in the annual seasons. The study shows a potential for shifting heat loads in time on a neighbourhood level.
Experimental and numerical investigation of a thermal storage medium for ground source heat pump applications
Authors: Mwesigye A , Nguyen H V , Salt D , Daneshazarian Reza , Dworkin S B 
Published: October 2019

Abstract
As a means of improving performance and alleviating thermal imbalance issues associated with ground source heat pump systems, ground thermal energy storage is becoming increasingly appealing. Moreover, an efficient means of transferring energy from the borehole to the surroundings is crucial. In this paper, an experimental and numerical investigation of the performance of a thermal storage medium for ground source heat pump applications is presented. A thermal storage tank of 1 m diameter and 1.5 m height equipped with temperature sensors at different radial positions and depths was used. It incorporates a 150 mm-dimeter steel pipe in which a 25.4 mm u-shaped pipe is placed to emulate a borehole. A numerical model was developed using a finite element-based approach and validated with the obtained experimental data. Different bentonite-sand mixtures with varying thermal conductivities were considered inside and around the emulated borehole. A reduction in the tank temperature difference of about 57% was achieved by using bentonite-sand mixtures inside the borehole and around the borehole (in the tank) compared to using only bentonite inside the borehole and sand around the borehole. Results further show that the heat transfer performance increases by about 320% with the use of the bentonite-sand mixtures compared to the separated bentonite and sand arrangement. Moreover, the potential for energy storage with phase change material around the emulated borehole has been demonstrated.
Performance of VRF systems based on large scale monitoring
Authors: Liu Hua , Qian Mingyang , Yan Da , Berardi Umberto 
Published: October 2019

Abstract
Variable Refrigerant Flow (VRF) systems are refrigerant systems, which are generally comprised of an outdoor unit serving multiple indoor units connected by a refrigerant piping network. It is important to evaluate the performance of VRF systems, which can help the design and operate of VRF systems. Performance test done by manufactory can reveal the performance of VRF systems in designed conditions. However, it is hard to reveal effective performance in real buildings. The field test is complicated compared with the test in the laboratory and can only conduct on typical samples rather than large scale samples. However, typical samples are not enough for reflecting the performance of large scale VRF systems samples. A simple method of evaluating the performance of large scale VRF systems samples is necessary. This paper proposed and calculating model for electricity consumption and cooling demand of VRF systems based on measured operating data in the laboratory. The paper used the calculating model combined with 344 samples operating data from real residential buildings to calculate the performance of a large scale VRF. This paper analyzed the VRF systems’ performance with different influencing factors such as climate zones, cooling duration and outdoor temperature for the recommendation for VRF systems’ designing and operation.
Residential dual core energy recovery ventilation system for ventilation of northern housing
Authors: Ouazia B , Won D. , Arsenault C , Li Y 
Published: October 2019

Abstract
Heat/energy recovery ventilation systems are types of HVAC that can reduce energy consumption and improve the ventilation rate of housing in cold climates. Their performance achieved to date has been inadequate due to equipment failures (freezing of cores, noise, etc.). Freezing of cores is common in extremely cold climates. Single core HRV/ERV units are usually equipped with defrost strategies such as recirculation of exhaust stale air across the heat exchanger and back into the supply air to the house. These defrost strategies can undermine ventilation standards (ventilation rate requirement not being met during recirculation). This paper presents a rigorous investigation on the performance of dual core energy recovery system that provided a continuous ventilation rate at outdoor temperatures below -10°C without frost protection. The dual core ERV had higher apparent sensible effectiveness (up to 12% more) and apparent total effectiveness (up to 9% more) than a conventional single core ERV. It showed no sign of frost problems after four weeks of winter testing, continuously provided outdoor air without stopping to defrost, unlike the conventional single core ERV which required up to 7.5 hours defrosting per day, and also provided a higher supply air temperature (up to 3°C) to indoors with a total whole-house energy saving of 4.7%.
Study on the heat transfer performance of the ceiling radiant panel
Authors: Ichikawa Yuki , Kuwahara Ryoichi , Sato Hideki 
Published: October 2019

Abstract
The purpose of this study is to acquire data to examine the design method of radiant air conditioning in Japan. The radiant panels were installed in the population weather chamber, and the convective heat transfer coefficient and the radiant heat transfer coefficient on the upper side and the lower side of the radiant panel were experimentally calculated. As a result of this experiment, the radiant heat transfer coefficient was larger than the convective heat transfer coefficient during cooling and heating. In addition, CFD simulation of the thermal environment and airflow in the environmental control chamber was conducted. From the simulation results, it found that there was almost no temperature unevenness in the environmental control chamber, and the air flow was very small. There were differences in the comparison between the experimental values and the analysis values of the vertical temperature distribution.
Performance evaluation of Active Chilled Beam under cooling operation in real office conditions in a high-performance building
Authors: Upadhyay Rohit , Mora Rodrigo 
Published: October 2019

Abstract
This study investigates the operation of Active Chilled Beam under cooling operation in single occupant office in a high-performance LEED Gold Building at the British Columbia Institute of Technology in Vancouver. The thermo-fluid phenomena of room air were studied inside a few offices under cooling operation in stable room temperature conditions. Active Chilled Beams were found performing effectively in cooling mode operation. Surface temperature distribution and the air temperature distribution in the occupied zone were found uniform at all heights and close to the room setpoint. The air velocities were within the recommended air velocity set by ASHRAE Standard for thermal comfort except at the colliding jet between two beams in some offices. The operative temperature measured near the occupant was found close to the room setpoint. The supply air velocity and supply air temperature at both the slots of the beam were found different. It was concluded that the difference in supply air velocity could be due to the uneven pressure distribution in the primary air plenum owing to the connection method of the duct to the primary plenum and the difference in temperature could be due to the circuit arrangement of heat exchanger inside the Active Chilled Beam, which needs further research and investigation of the beam characteristics in a controlled environment.
Evaluation of thermal comfort and heat stress indices in different countries and regions – A Review
Authors: Yasmeen Sadia , Liu Hong 
Published: October 2019

Abstract
Energy efficiency, sustainability, productivity, thermal comfort, occupational health issues are emanating from rising global temperature associated with climate change. The prime purpose of this review is to focus on the present models to evaluate thermal comfort and heat stress level in various parts of the world in order to, identify the significant limitations in the development appropriate model. To assessed thermal comfort and heat stress a considerable number of models are already existing where about 40 models exist for only to determine heat stress itself. Existing comfort models are criticized for less metabolic rate, cloth insulation, not suitable for the outdoor diverse climate or for over or underestimation of the thermal concessions. On the other hand, to assessed heat stress WBGT-index is most widely used because of its simplicity. Several studies raised its limitations, whereas the PHS model is more appropriate but hard to understand for general people. For Thai people, HSI (Heat Stress Index) is best rather than others claimed by the authors. Thermal Work Limit (TWL) is suitable for both indoor and outdoor environments. Authors adopt the approaches to determine the region-based comfort and stress level through exploiting different models. For better evaluation models were improved through including or excluding new variables since the first development of thermal comfort indices. However, no unique model has developed afterward. Perfection and utilities of models depend on regional climatic behavior, which is apart from other relevant aspects. Therefore, further study should be necessary to establish a unique model or if not reasonable then focus on to obtain the accurate model for each climatic region.