bluuebunny/crossref_metadata_2025 huggingface dataset:
The investigation of indoor air quality and ventilation of an airport terminal building in China
Authors: Hong Jiajie , Lin Borong
Published: October 2019

This study aims to explore the actual indoor air quality and ventilation of an airport terminal building in Hot-Summer-Cold-Winter (HSCW) zone of China, based on long-term monitoring data of CO2 concentration, which were measured with 50 environmental sensors from September, 2017 to April, 2018.The key findings of this study can be summarized as follows: 1) The median values of CO2 concentration were lower than 550 ppm in all areas including check-in area, security check area, departure lounge with air bridges, arrival lounge, baggage claim area except the remote departure lounge; 2) Subjective questionnaire survey found that passengers were very satisfied with indoor air quality;3)The air contained in the large indoor space and the large amount of outdoor infiltrated air played an important role in the dilution of indoor pollutants; 4) Fresh air experiment showed that IAQ in the terminal building didn’t worsen without the supply of fresh air; 5)The number of air changes was calculated by the carbon dioxide attenuation method, and it was found that The arrival floor where gates are normally open and connected to the traffic center has large amount of air exchange. Building energy simulation results revealed that 24% heat was lost in winter through fresh air heating and 57% through air infiltration. In addition, the suggestions for ventilation improvements were also proposed.
The assessment of natural ventilation performance for thermal comfort in educational space: a case study of design studio in the AAST-Alexandria
Authors: Sarhan A , Abd El Gelil R , Awad H
Published: October 2019

Through the last decades, the impact of thermal comfort on the working performance of users and occupants of an indoor space has been a concern. Research papers concluded that natural ventilation quality directly impacts the levels of thermal comfort. Natural ventilation must be put into account during the design process in order to improve the inhabitant’s efficiency and productivity. One example of daily long-term occupancy spaces is educational facilities. Many individuals spend long time receiving a considerable amount of knowledge and it takes additional time to apply this knowledge thus, this research is concerned with user’s level of thermal comfort in design studios of educational facilities. The natural ventilation quality in spaces is affected by a number of parameters including orientation, opening design and many other factors. This research aims to investigate the conscious manipulation of space physical parameters and its impact on natural ventilation performance which subsequently affects thermal comfort of users. The current research uses inductive methods to define natural ventilation design considerations, which are used in a field study in a studio in the university building in Alexandria (AAST) to evaluate natural ventilation performance through analysing and comparing the current case to the developed framework. Also, the study conducts a computational fluid dynamics simulation. Results have proved that natural ventilation performance is successful by only 50% from the natural ventilation design framework, these results are supported by CFD simulation.
The challenges of designing a NRVU-BVU for energy efficiency and enhanced IAQ
Authors: Cross A
Published: October 2019

Directive 2009/125/EC establishes a framework for the setting of Ecodesign requirements for energy- using products. ‘Many products have a significant potential for being improved in order to reduce environmental impacts and to achieve energy savings through better design which also leads to economic savings for businesses and end-users’ [1]. Commission Regulation (EU) No 1253/2014, also known as Ecodesign directive 1253/2014/EC, applies to ventilation units and establishes ecodesign requirements for placing on the market or putting into service. The ecodesign requirements should be introduced gradually in order to provide a sufficient timeframe for manufacturers to re-design products subject to said regulation. This discussion paper highlights the practical challenges of designing a compliant non-residential bidirectional ventilation unit (NRVU-BVU) with the aim of improving energy efficiency whilst enhancing indoor air quality and discusses potential options to meet or exceed the requirements.
Experimental study of thermal characteristics for a novel ventilation roof with composite phase change material (VRCPCM)
Authors: Kong Xiangfei , Li Xiaofei , Qiao Xu , Chang Yufan , Chen Wanhe
Published: October 2019

A phase change material particle (PCMP) was prepared by vacuum adsorption method, with the binary eutectic mixture of myristic acid and tetradecanol as phase change material (PCM) and expanded vermiculite (EVMT) as porous adsorption materials. Then PCMPs were pressed into composite phase change plates (CPCP) for the outside layer of roof to store the heat passively. The active cooling storage was provided by the cold water in the seamless steel pipe and the iron box containing binary eutectic mixture of lauric acid and tetradecanol on the indoor side. Combined with the ventilation roof, a novel ventilation roof with composite phase change material experimental hut was constructed. The cold storage performance test was conducted under the two strategies which were regularly opened ventilation layer at certain time and timing cooling while regularly opened ventilation layer. The first strategy result showed that CPCP effectively reduced the temperature of the outer surface of the roof and the ventilation layer was turned on at night, which could effectively reduce the indoor air peak temperature. The second strategy result under the active cooling condition showed that the indoor PCM could absorb the heat of the indoor air and reduce the indoor temperature and the indoor temperature fluctuation range.
Study on energy loss through door open while air conditioner running in commercial store
Authors: Lee Sihwan
Published: October 2019

While air conditioner is running, leaving doors and windows open is a great way to reduce operating efficiency and undermine the air conditioning system’s ability to bring the indoor to a comfortable temperature. However, merchants want to business with open the door to attract more customers and to increase sales. The purpose of this study is to evaluate the heat loss and thermal environment through the door open while air conditioner running. To achieve this goal, using full-scale measurement with the commercial store during the cooling period, the infiltration rate, thermal environment and energy consumption of air conditioner with door opened and door closed state were measured. The measured results show that the infiltration rate at the door opened state was increased by about 21.3 times compared to the door closed state. When the set temperature of the air conditioner was 24 °C, the room temperature with open the door was measured to be about 5 °C higher than the cases of close the door. However, the energy consumption was measured approximately 12 kWh/day and there was not difference with door state. This means that the energy consumption is not increased if the indoor air temperature would not reach the set point temperature of air conditioner.
An analysis of the ventilation rates in residential buildings
Authors: Yoo Jihyun , Lee Seungrim , Park Junseok
Published: October 2019

The ultimate goal of environmental buildings is to minimize the use of fossil fuels and resources while providing a comfortable environment for occupants. Through continuous research and development, the physical performance of the buildings has been greatly improved for this purpose. However, focusing only on physical performance, it is seen that there is a big discrepancy between predicted and actual performance of building by treating occupants, who are the most affective object of building and energy consumption, as simple passive elements. These results increase the energy and cost of the building and become an obstacle to the construction of environmentally friendly buildings. Among occupant behavior, window opening is the biggest factor of increasing heating and cooling energy consumption. The purpose of this paper is to analyze the ventilation rate of each window opening for being embedded in an energy simulation program. A method to analyze the ventilation rate was carbon dioxide decay method as shown in Fig. 1. As a result, the ventilation rate was affected by the wind direction and speed, and floor level, but was somewhat constant because of monsoon effect in summer and winter of Korea.
Measuring and identifying background noises in offices during work hours
Authors: Rossi E , De Salvio D , D’Orazio D , Garai M
Published: October 2019

In offices and working places, noise analysis aims at enhancing the acoustic comfort, the concentration and the oral communication quality. According to the current regulations, background noise is evaluated in unoccupied conditions, but it is interesting to know its dynamic behaviour in occupied state. The knowledge of the noise components may be useful for improving the estimation of comfort parameters, such as the distraction distance (ISO 3382-3) or Speech Transmission Index (IEC 60268-16). The present study suggests a method to extract background noises values with statistical techniques from recordings made during work hours with sound level meters. Statistical techniques were used for the analysis of short-time sound pressure levels obtained over long-term recordings: Gaussian Mixture and Percentile Levels. Noise sources are identified from octave bands analyses. Measurements done using Gaussian Mixture were compared with the ones done with Percentile Levels. Results show some differences between the two techniques.
Numerical simulation the effect of natural ventilation on Indoor Environment Quality in the inner-corridor-type student dormitory in winter
Authors: Li Zhuangzhuang , Li Kaiyue , Chang Jin , Wu Huazhen , Liu Jiying
Published: October 2019

Poor air quality in the dormitory will affect students’ physical and mental health and reduce their learning efficiency. The environmental status of university dormitory is gaining more and more attention. The indoor environment quality is always affected by outdoor condition during the heating period due to the requirement of natural ventilation. Using ANSYS Fluent software establishes a full-scale indoor and outdoor inner-corridor-type dormitory taking into account the different floor numbers. The results revealed that the living area on the south side of the corridor has a higher temperature and carbon dioxide concentration compared with the north side of the corridor. The balcony and corridor play an important role in maintaining the temperature of the dormitory. The mean velocity on the first floor is the lowest, and there is no significant difference in the air velocity in the living area on both sides of the corridor. The living area on the fifth floor has the better ventilation effectiveness. The results of this study will help architects understand the impact of natural ventilation on the indoor environment in inner-corridor-type dormitory.
Effect of air – exhaust location on surgical site particle distribution in an operating room
Authors: Agirman A , Cetin Y E , Avci M , Aydin O
Published: October 2019

This study investigates the effect of exhaust outlet location on airflow and particle distribution in an operating room with laminar ventilation system via computational fluid dynamics (CFD). Four different exhaust opening locations and three different particle diameters (5, 10 and 20μm) are taken into consideration for the same air change rate (30 ACH). It is found that the total number of particles deposited on the operating table decreased by 64 % for the smallest particle diameter (5 μm) and 26 % for the largest particle diameter (20 μm) when ceiling and floor level outlets are used together.
Novel methodology for diagnosis of causes associated with mould growth in dwellings
Authors: Lopez-Arce P , Altamirano-Medina H , Berry J , Rovas D , Sarce F , Hodgson S
Published: October 2019

Increased occupancy rates, inappropriate ventilation and intermittent heating regimes in dwellings can result in excessive atmospheric moisture levels, potentially leading to mould growth and lower indoor air quality. Identifying the causes associated to mould growth and taking correct remedial actions can be essential in reducing the prevalence of this problem. In practice it is often complex, even for experts, to accurately identify some of these causes and this can lead to costly and unnecessary interventions. Towards development of a novel systematic diagnostic procedure an extensive monitoring exercise has been undertaken involving collection of environmental data from dwellings with and without mould issues. The data has been analysed, considering building characteristics and occupancy’s lifestyle features, with the objective to identify thresholds on measurable parameters that are indicative of mould growth risks. The proposed methodology links key parameters to identify factors that contribute to surface condensation and mould growth in buildings. This research presents a process towards environmental data collection, post-processing to compute and interpret pertinent environmental parameters, and displaying them in a clear and easy-to-interpret manner.
Sensitivity analysis of envelope design on the summer thermal comfort of naturally ventilated classrooms in Taiwan
Authors: Chen Y H , Hwang R L , Huang K T
Published: October 2019

This paper uses Monte Carlo Analysis (MCA) for sensitivity analysis of the influence of sunlight shading and ventilation performance of classrooms in Taiwan on students’ cumulative overheating risk and average learning efficiency. The parameters influencing the sunlight shading and ventilation performance of classrooms include window orientation, window opening rate, ventilation rate, and external shading depth. EnergyPlus and local TMY3 weather data are used to simulate the hourly thermal environment conditions of 400 sample classrooms in two climatic regions (Taipei and Kaohsiung). The sensitivity of design parameters to the thermal risk of naturally ventilated classrooms and students’ learning efficiency is judged by using standardized regression coefficient, and the order of importance is window opening rate, ventilation rate, orientation, and external shading depth.
IoT network-based ANN for ventilation pattern prediction and actuation to optimize IAQ in educational spaces
Authors: Tagliabue L C , Re Cecconi F , Rinadi S , Ciribini A L C
Published: October 2019

Nowadays, in a user centered design approach, one of the main parameters for assessing the well-being of building spaces is Indoor Air Quality (IAQ), which can assure a crucial level of comfort and optimal conditions to preserve users’ productivity and cognitive performance. Research works in this direction mention that with 1000 ppm of CO2 concentration, a reduction of the users’ cognitive performance about 11-23% is reported and, for a concentration of 2500 ppm, the decrease reaches 44-94% compared to the performance at 600 ppm. Consequently, a correct buildings ventilation is crucial. The use of mechanical systems seems possibly to avoid the problem but indeed the existing buildings often have outdated and not flexible systems to face changing needs. Thereby, the ventilation rates are not related to people density and the static setup of HVAC systems might be an issue to maintain an acceptable level of CO2 concentration. Moreover, in school buildings, mechanical ventilation is not diffusely adopted and insufficient rates of fresh air supplied to the classrooms are connected with inappropriate IAQ, occurrence of SBS symptoms among pupils. Current technology provides easy measurement of CO2 through dedicated sensors networks. The present research uses the pilot educational building eLUX, located in the Smart Campus of the University of Brescia, to investigate the possibility to integrate IAQ data generated by IoT sensors to improve the estimation of occupancy rate in the educational spaces. The aim is to underline the relevance of the parameter to regulate properly the HVAC systems and to define opening/closing patterns for automated windows to enhance IAQ. The data collected during the monitoring phase are useful to train an Artificial Neural Network (ANN) that through an IoT communication protocol could actuate the ventilation rate control.
Simulation analysis of Macro-Packed Phase Change Materials (MPPCM) to reduce building energy use
Authors: Yeol Yun Beom , Yang Sungwoong , Hun Park Ji , Lee Jongki , Wi Seunghwan , Kim Sumin
Published: October 2019

This study sets up a zone-construction combination by constructing walls based on the classification of climates classified according to Korea’s energy saving design standards and the heat paring rate standard of the wall. There are four climatic divisions, C1, C2, S, and J, and we have used representative climate data for each climate. The target building was a residential apartment, which is the main residential type of large cities in Korea and the world. In the set combination, PCM of TES system is placed indoors, and applied PCM is n-hexadecane, n-heptadecane, n-octadecane with phase change temperature of 20-28 °C corresponding to room temperature standard. Each PCM is set at 0.1% to 0.9% of the area of the building. We used Energy Plus 8.7, a building energy simulation, and analyzed the energy saving and economic efficiency of the building. Saved energy was 2.71% on average and we were able to save up to 4.56%. In addition, we conducted an economic analysis, saving an average of 3.42% and saving up to 7.48%.
Investigation of particle detachment from the rotating wheel in indoor environment
Authors: Song J W , Qian H , Zheng X H , Liu F
Published: October 2019

There are various wheels are required for indoor activities, such as spinning bike wheels in the gym, various mechanical equipment wheels in the factory. Obviously, these rotational movements of wheels will cause the detachment of particles adhering to the wheel. This common phenomenon is regarded as an important contributor to particulate matter concentrations in indoor environment. The work performed in this study mainly focused on the description and understanding of the process of particles detachment from the rotating wheel into the air. A set of theoretical models were proposed to clarify particle detachment mechanisms. Since the detachment occurs when the sum of external force moments exceed the maximum adhesion resistance moment, different forces acting on the particles should be considered before the particles detached. There are adhesion forces between the particles and the wheel surface, hydrodynamic forces acting on the particles and centrifugal forces due to the rotating wheel. In order to verify models, the corresponding experiments were carried out and the experimental results were quite consistent with the calculation results of models. Results showed that adhesion force, hydrodynamic drag force and centrifugal force were important and critical detachment diameters of particles adhering to the wheel can be influenced by these forces. Effects of different relevant parameters on these forces, including surface roughness, wheel speed, particle size were analysed. Higher roughness, larger particle and faster wheel speed are more conducive to the detachment of particles.
The effect of student activity and outdoor conditions on particulate matter concentration in university classroom
Authors: Park S W , Song D S
Published: October 2019

The university lecture room is one of the places where the fine dust concentration can rise easily. Generally, since students move in each lecture, particulate matter formed in the outdoors is adsorbed on the clothes surface of the students and then re-suspended in the room. Also, university classrooms are often blocked for more than one hour of class, and the university’s old buildings do not have a special ventilation system. In addition, when the number of students per unit area per class is large, much particulate matter can be re-suspended due to the activities of the students. The purpose of this study is to investigate the relationship between factors affecting the concentration of particulate matter in the classroom by long-term field measurements.

Particulate matter has been measured for long periods in two classrooms, hallway, and outdoor. At the same time, factors affecting the indoor particulate matter concentration such as cleaning status, window and door opening status, air conditioner operating status, and number of occupants per unit area were monitored. As a result, the increase and decrease of the outdoor particulate matter concentration had a great influence on the increase and decrease of particulate matter concentration in the classroom. At the beginning or end of the lesson, indoor and corridor particulate matter concentrations increased sharply with the movement of many students. The increased particulate matter concentration was maintained for a long time despite the window and door open condition.
On the temporal dimension of adaptive thermal comfort mechanisms in residential buildings
Authors: Ryu Jihye , Kim Jungsoo , Hong Wonhwa , de Dear Richard
Published: October 2019

In response to the change of indoor thermal environment, building occupants constantly interact with the surrounding environment through various adaptive behaviours. The purpose of this study is to better understand the adaptive thermal comfort mechanisms by investigating the interrelationship between the expectation of the occupants (the psychological adaption), their behavioural adjustment (the physical adaption), and the indoor thermal environment in the context of residential buildings. Eleven households in South Korea participated in this longitudinal field study carried out between 2015 and 2017. The indoor thermal environmental parameters, the occupant subjective evaluations of thermal comfort, and their adaptive behaviour pattern were monitored. On average, 1,512 datasets from each household and a total of 16,632 datasets were collected and analyzed. Our analysis focused on understanding both the temporal dimension (i.e. duration of thermal discomfort episodes) and the intensity of stimuli (i.e. deviation from the comfort zone) both before- and after the participants’ decision on the use of air-conditioners. The study proposes the constructs of ‘discomfort capacity’ and ‘comfort restoration’ as multi-dimensional indices to better understand the triggering mechanisms for household air-conditioner usage. Using these indices, the study quantified householders’ tolerance of thermal discomfort events before they resort to air-conditioning.
Measurement of airborne ultrafine particles in work and life environments: study design and preliminary trends in an Italian university site.
Authors: Boccuni F , Ferrante R , Tombolini F , Iavicoli S , Pelliccioni A
Published: October 2019

Airborne ultrafine particles (UFPs) potentially have adverse health effects for the exposed population both in life and work environments. Main objective of this study is to propose a strategy to measure multiple parameters that may influence human exposure to UFPs and apply it in a case study at the university site of “La Sapienza” in Rome (Italy). The measurements allow the characterization of UFPs in terms of particle number concentration (PNC), particle size distribution (PSD), lung deposited surface area (LDSA), geometric mean diameter (GMD) and polycyclic aromatic hydrocarbons concentration (PAHs), using data collected in indoor and outdoor conditions by real-time instruments with high time resolution. The study design includes: i) inter-comparison of devices based on different principles of operation to harmonize the outputs in relation to a reference instrument; ii) case study site description and sampling points identification to allow indoor vs outdoor relations at different height; iii) extensive measurement campaigns to provide a dataset useful to data comparison; iv) statistical data series analysis. The preliminary results reported here are related to the values of PNC and calculated average diameter (Davg) for airborne UFPs, obtained in three different sampling points of the research workplaces at the university site: auditorium (about 300 places - ground floor), computer science laboratory (about 50 workstations - first floor) and external roof (top of the building). Major relations between PNC and Davg have been highlighted in daily trends.
Residential indoor pollution by nitrogen dioxide: conference series
Authors: Miškinytė A , Dėdelė A
Published: October 2019

According to the Environmental Protection Agency, indoor air quality (IAQ) is defined as air quality within and around buildings and structures and it is related to the health and comfort of building occupants. A better understanding of IAQ is essential, since people spend more than 90 percent of their time indoors. The greatest amount of time spent indoors is at home, so it is important to control indoor air pollution and to reduce the risk of health effects related with indoor air pollutants exposure. The aim of this study was to determine indoor air pollution of nitrogen dioxide (NO2) in different seasons and to compare indoor and outdoor NO2 concentrations. The sampling of NO2 was performed in cold, warm and intermediate seasons using passive sampling technique inside and outside of the residential houses. The results of the study showed that the average NO2 concentration in cold season was 10.5 μg/m3 and 20.0 μg/m3, respectively in indoor and outdoor air. The lowest indoor and outdoor levels of NO2 were observed in warm season, 9.7 and 11.3 μg/m3, respectively. The strongest positive relationship between indoor and outdoor concentrations of NO2 was determined in warm season.
A field study on the effect of cold radiation on human thermal comfort in winter
Authors: Xu Yunyan , Wang Zhaojun , Su Xiaowen , Lu Wenjing
Published: October 2019

A field survey of indoor thermal environment was conducted on four office buildings in Harbin. It aims to research the effect of cold radiation on human thermal comfort in winter. The results showed that the average indoor temperature of buildings with floor heating (FH) systems was as high as 27.53 °C, which was 3.2 °C higher than that of the buildings with radiator heating (RH) systems. And thus indoor environment was too warm in FH rooms which seriously affected occupants’ thermal comfort. In addition, FH building was less affected by cold radiation from the external windows and walls. However, people complained local thermal discomfort of legs and feet under the overheated environment. In RH buildings, among the votes of local thermal sensation, a large amount of subjects who were within 2m from external windows voted “cold” and complained “shoulder” and “back” were significantly suffered by the cold radiation from exterior envelope.
The impact of some factors (building materials, seasonality) on indoor radon content in Chelyabinsk region, Russia
Authors: Mashkova I V , Kostryukova A M , Schelkanova E E , Slavnaya A I
Published: October 2019

This paper reports the results of a study which explores the rate of indoor radon content in four settlements of Chebarkul district in Chelyabinsk region, Russia. A large number of heterogeneous rock formation areas with inclusions of thorium and uranium mineralization is a distinguishing feature of Chelyabinsk region. The natural γ-background in the study area is 110 mSv⋅h−1. The study provides the obtained results of radon content in winter, spring, summer and autumn in rooms in buildings made of wood, brick, concrete panels. Y-background and equivalent equilibrium volume activity were measured in open areas and in premises with ergonometric PAA-10 and “Alpha Guard 2000”. The average annual equivalent equilibrium volume activity of radon for all buildings varied greatly depending on the materials used for construction (from 21.5±2.2 to 176.2±15.6 Bq⋅m−3). The highest values were recorded for the premises made of wood. According to the indoor radon content in the premises made of different building materials, the studied settlements were classified into several categories of being radon hazardous (the first, second and third). The range of annual average values of equivalent equilibrium volume activity in different premises was identified in the reducing order which is the following: winter - autumn - spring - summer. The differences of the mean radon content in different seasons were statistically significant. Conservative estimates of annual doses of radon in all the studied premises ranged from 120 mSv⋅year−1 to 195 mSv⋅year−1, depending on the type of construction.
Development human thermoregulation model for Korean young and older men
Authors: Choi HeeWon , An YoungMin , Cho SungWon , Park Junseok , Yun SeoYeon , Kwak JiYoung , Chun ChungYoon
Published: October 2019

The Purpose of this research is to develop the Korean of human physiology model and thermal comfort assessment. As a first step, we developed models for young men and older men, which calculate the skin temperature of each body segments and predict the thermal sensation of indoor environment. The typical body for 20-30 (younger) and 40-50 (older) years old of Korean men modelled using the data that gathered from ‘National Anthropometric Survey of Korea 2010 (Size Korea)’. In order to calculate the surface area and mass of the models, these data used to calculate the surface area of each segment using the formula of Dubois and Dubois’s and the mass of each segment using a study of Stolwijk. Using the developed models, the local skin temperature was predicted and compared. In the neutral environment, the body parts in the 4-50s were smaller in surface area and mass than those in the 2-30s, resulting in smaller predicted skin temperatures. In case of the mass of the segment was increased, the change of skin temperature was different according to the part.
Primary air treatment vs energy saving: comparison between different design solutions
Authors: Emmi Giuseppe , Zarrella Angelo , Mariotti Marco , De Carli Michele
Published: October 2019

In civil application the most diffuse type of HVAC is the mixed one made by fancoils and primary air system. Usually the primary air has not only the aim of replace the exhaust air in the rooms. During the cooling season air plants have the task of dehumidification of the indoor air which is humidified by the indoor humidity sources, like the human skin transpiration and breathing of the people. On the other hand, during the heating period the fresh air must be humidified to compensate the low humidity ratio of the external air. With the aim of energy saving related to the ventilation in buildings, from the beginning 2018 the new European Regulation EU 1253/2014 has been introduced some limits in terms of energy efficiencies. The present work investigates different layouts of plants for the primary air treatment in HVAC systems. Several types of heat recovery units have been considered in the study in order to find which is the best solution for the optimization of the air treatment. Several case studies have been considered in the energy analysis and the results obtained through numerical simulations have highlighted the critical nature of the interventions aimed at limiting energy consumption in primary air treatment systems.
Introduction of hybrid radiant cooling system for adapting hot and humid climates
Authors: Kim M K
Published: October 2019

The main purpose of this study is to introduce a hybrid radiant cooling system which combines a conventional radiant cooling panel with an Airbox convector hydronically connected in series for adapting hot and humid climates as a novel radiant cooling strategy. This novel system can reduce moisture condensation risks on a surface of chilled ceiling panel and generates additional cooling capacity because the Airbox convector can dehumidify indoor air when indoor humidity level is increased and it enhances a mixed convection effect which combines natural convection with mechanical forced convection effect. And this system simply adjusts cooling output by the Airbox’s fan control and indoor air pollution rate because the Airbox includes an air filter, therefore, this system can be adapted to various indoor thermal conditions. This paper presents strategies to use the system effectively and to save cooling energy consumptions. And this study demonstrates systematic strategies how the hybrid radiant cooling system can minimize main challenges of using typical radiant cooling system and improve cooling and dehumidification performance in various thermal conditions.
Application of air-source heat pump (ASHP) technology for residential buildings in Canada
Authors: Udovichenko Artur , Zhong Lexuan
Published: October 2019

The air-source heat pump (ASHP) is a relatively new, highly efficient technology which has been proven to be a feasible alternative in mild temperature climates. However, an ASHP’s application tends to be limited by outdoor temperature in cold climate zones. This study was intended to explore the feasibility of ASHPs in conjunction with traditional furnaces to serve as an innovative energy efficient method for heating homes in Canada. The goal was to quantify the cost and emissions savings of an ASHP hybrid heating system as compared with a furnace-only system for a residence in three Canadian cities. A prototypical residential building with a hybrid heating system was generated for heating load calculations. The theoretical analysis included the determination of the outdoor-temperature-dependent heat loss rate from the residence and heat supply rate of ASHPs. The building model has proved to be useful for further analyses, while the feasibility of the hybrid system has been determined to be highly region dependent.
Performance comparison between metal-organic framework (MOFs) and conventional desiccants (silica gel, zeolite) for a novel high temperature cooling system
Authors: Zu Kan , Cui Shuqing , Qin Menghao
Published: October 2019

The use of desiccant-coated heat exchangers (DCHE) in air conditioning systems possesses great advantages in the independent control of both temperature and humidity, as well as low energy consumption and high coefficient of performance (COP). The paper presents a novel high temperature cooling system that uses metal-organic frameworks (MOFs) as sorbents for humidity control. MOFs are a new class of porous crystalline materials consisted of metal clusters and organic linkers, which have an excellent performance of water sorption due to the large specific surface areas and high porosity. In this research, we directly coat MOFs on the heat exchange surface of evaporator and condenser. The evaporator can simultaneously remove both the sensible and latent loads of the incoming air without reducing the temperature below its dew point. The regeneration of wet MOFs is completely driven by the residual heat from the condenser. We also make comparison between the MOF-coated cooling system and conventional desiccants coated ones (i.e. silica gel, zeolite) by way of tests and calculation. The results indicate that the dehumidification capacity of the MOF-coated heat exchanger outperforms other conventional desiccant coated ones under low regeneration temperature (∼50°C). The MOF-coated system has a high COP, up to 7.9, and can save 36.1% of the energy required, compared to the traditional vapour compression system with reheating. The amphiphilic MOFs used in the study have high water uptake and low regeneration temperature, and they thus have the potential for being scaled up for large-scale applications in energy efficient air conditioning systems.
Multiple regression analysis on the HVAC energy consumption of railway passenger stations
Authors: Su Z , Li X
Published: October 2019

With the rapid development of high-speed railway transport in the last decade, the number of railway passenger stations in China has surged. Distinguished by its large floor space, high quality of service, long operation time and high occupancy rate throughout the year, the electricity consumption of the heating, ventilation and air conditioning (HVAC) system for current railway stations is much higher than other types of public buildings. Despite of its huge amount of energy consumption, the assessment standard and benchmarking for the railway passenger stations is not completely established. Therefore, it is of great significance to study the energy use level and the associated factors of influence. In this paper, extensive field tests have been conducted to collect detailed energy data of stations in different climate zones in China. Multiple regression model is adopted to determine relevant impacting parameters. The results showed that building area tends to be the primary factor affecting the energy consumed by the HVAC system in each of the four climate zones. Furthermore, for each climate region, regression equations are developed, which serve as an effective standard to evaluate the energy consumption of stations.
Energy flexibility analysis of office building using pre-cooling with structural thermal mass
Authors: Lu Fei , Yu Zhenyu , Yang Xudong , Zou Yu
Published: October 2019

The increasing share of renewable energy sources (RES) increases the imbalance between supply and demand, due to its fluctuation and intermittence. Eenergy flexible buildings are proposed as an important part of the solution to balance supply and demand. However, the thermal storage of a building is not utilized for reducing the considerable peak-to-valley difference in conventional night setup control strategies. In this context, pre-cooling is the most commonly used approach for charging cooling in building thermal mass to achieve energy flexibility. The objective of this paper is to assess the building flexibility potential using pre-cooling with structural thermal mass. We proposed quantitative indexes including valley-filling capacity, peak-shaving capacity and energy-shifting efficiency based on the improvement of existing indicators according to previous research. As considering the impact of structural thermal mass, heat transfer coefficient, pre-cooling duration, pre-cooling temperature on energy flexibility, a total of 35 scenarios are simulated using TRNSYS and evaluated using the quantitative indexes. Finally, the results may supply suggestions to utilize building energy flexibility with pre-cooling and optimize the corresponding control strategy.
Optimal control for the natural ventilation in buildings with large depth
Authors: Wang Fulin , Yan Rui , Liu Yansheng
Published: October 2019

This article proposes an optimal control method for the natural ventilation in buildings with large depth. Through designing control strategy, constructing building model, simulating the performance of natural ventilation under different control strategies, the optimal positions of the natural ventilation opening at different floors are decided to achieve the maximum free cooling and minimum cooling consumptions while ensuring the indoor air quality healthy. By using simulation, the cooling energy consumptions at three typical climate conditions, i.e. cool day, warm day, and moderate day, are simulated under two different control strategies, i.e. the proposed optimal control and traditional on/off control of natural ventilation opening. Based on the simulated energy consumptions at the three typical climate conditions, the annual total cooling energy consumptions are estimated. The annual total energy consumptions of optimal control can save cooling energy by 43.5% compared with the traditional on/off control, which shows the energy saving potential and the application prospective of the proposed optimal control method.
Auto-tuning method for data-driven models in building energy consumption prediction: a case of cooling load prediction
Authors: Kang Xuyuan , Yan Da , Jin Yuan , Sun Hongsan
Published: October 2019

Building consumes a significant portion of energy in the world. Improving energy use efficiency in building sector is a key approach of achieving sustainable and environmental friendly development targets. Building energy consumption prediction is essential for energy planning, equipment control and system management. Traditional physics-based model is widely used but requires sophisticated input parameter. Data-driven models, on the other perspective, utilize historical data to make predictions for future scenarios. However, the accuracy of this model greatly relies on the parameters of the machine learning algorithms within. This research proposes an auto-tuning method for machine learning algorithms in building energy prediction models, and discusses the difference between global optimum and local optimum. Based on this research, the accuracy and efficiency of the data-driven models are significantly improved.
Validation of thermoregulation human model considering mist wettedness on mist spraying environment
Authors: Oh Wonseok , Ooka Ryozo , Nakano Junta , Kikumoto Hideki , Ogawa Osamu
Published: October 2019

Mist spraying systems can relieve thermal discomfort in extremely hot weather. However, the thermal effect of the mist spraying system on the human body has not been investigated sufficiently. To understand a physical phenomenon between human and surrounding environment, and physiological responses of the human body in mist spraying environment, the thermal state of the human body were predicted using the 2-node model (2NM). Sixty-five subjects’ skin temperatures and four environmental factors (air temperature, mean radiation temperature, relative humidity, and airspeed) were measured simultaneously. The mist spraying system caused the surrounding temperature to fall by 3.6 ± 1.4 °C and relative humidity to rise by 15.9 ± 4.7%. In addition, when the overall skin temperature was predicted using the conventional 2NM with measured environmental factors as an input parameter, the skin temperature was increased in mist spraying environment as opposed to the subject experimental results. However, when the mist wettedness is additionally considered in the thermoregulation human model, the decreasing skin temperature in the mist spraying environment was predictable considering the heat loss of the mist particles evaporated from the body surface. The mean error between the predicted and the experimental results showed a result of 0.4 °C. In conclusion, it was found that the mist wettedness is a key factor to predict human thermal conditions in the mist spraying environment accurately.
Cost-effective MEP solutions for a Passivhaus multi-family building in Mediterranean climate
Authors: Russo P. , Colaci De Vitis G. , Faganello S.
Published: October 2019

A compact integrated unit for heating, cooling and mechanical controlled ventilation as a perfect solution for a Passivhaus certified multi-family building in Southern Italy (warm climate). An individual application for each apartment helping the single customer to achieve an autonomous control of each thermal parameters, reducing cost and installation plant’s complexity. The compact system consists of a heat pump capable of recovering the extraction air flow heat to transfer it to the renewal air flow and to a domestic hot water tank. The extraction and renewal flows, pass through a recovery heat exchanger with high efficiency, in order to maximize the energy performance of the whole unit. To cover peak loads, related to the climatic conditions and user behaviour, a split system unit is used for air conditioning by recirculate the internal air. The unit allows a thermal integration function, cooling and dehumidification. The treated supplementary air, is delivered to the rooms through a specific distribution and the internal unit is located in the ceiling in a central part of the flat. A control system permits the operation of both the units comparing the measured parameters to the required comfort set point.
The impact of urban parameters on the ventilation in idealized urban model with fixed area
Authors: Yang Li , Weng Miao-cheng , liu Fang , Wang Kaixuan
Published: October 2019

With population growing rapidly, the lack of land is becoming serious. In order to make full use of land, more and more buildings are built in a limited area and the building height is higher and higher. However, the change of the building height and building density has the significant impact on the efficiency of the urban ventilation. This papers investigates canyon ventilation under neutral atmosphere condition with same building area density (λp
= 0.25) and fixe ground area (300mX300m) but various frontal building area density (λf
= 0.075∼0.425), plot ratio (λr
= 2.52∼4.00). The roof air change rate per hour (ACH
roof
) induced by turbulence and the horizontal air change rate per hour (ACHhorizontal) induced by mean flow, calculated by the CFD simulation by standard k – ε model, is adopt to quantify the vertical and horizontal air exchange, respectively. The results show that: 1) with the increase of the frontal building area density (λf
), ACH
roof
increases logarithmically and ACHhorizontal decays exponentially. With the increase of λf
, the resistance of buildings to airflow increases gradually, this is why the ACHhorizontal decreases exponentially, the remaining air flow is discharged through the roof, so ACH
roof
increases logarithmically, but the sum of ACHhorizontal and ACH
roof
is constant, equal to 10.2h
−1. 3) ACHhorizontal is negatively correlated with plot ratio, while ACH
roof
is positively correlated with plot ratio. This is because plot ratio represents the building density, drag force increases with building density. This study can be used to guide urban planning and improve urban ventilation environment.
Using smart technologies to identify occupancy and plug-in appliance interaction patterns in an office environment
Authors: Tekler Z D , Low R , Blessing L
Published: October 2019

There has been a widely documented phenomenon identifying an energy performance gap between the building’s design and operational phases. This result has been attributed to the stochastic behaviours exhibited by the occupants, who are assumed to follow deterministic and routine schedules. With the recent advancements in smart monitoring technologies, the increasing affordability of wireless sensors has allowed researchers to collect detailed information on the occupants’ dynamic behaviours. However, past applications of such technologies have been highly intrusive and limit the validity of the data collected due to the Hawthorne effect. Therefore, this paper proposes a non-intrusive data collection methodology using a comprehensive range of wireless smart meters, Bluetooth beacons, and questionnaires to capture the occupants’ movement and appliance interaction patterns. The feasibility of the approach is demonstrated during a two-week data collection effort in a university office. By combining the occupants’ presence with appliance energy consumption data, the authors were able to identify the occupants’ appliance interaction patterns. An extension of this work includes the use of the data collected to identify different occupancy and appliance interaction profiles, which contributes to the development of an appliance interaction model that addresses the energy performance gap caused by occupants’ appliance interaction.