bluuebunny/crossref_metadata_2025_split huggingface dataset:
Air conditioning system online control by incorporating low-dimensional linear models and intelligent predictions
Authors: Ren Chen , Jie Cao Shi 
Published: October 2019

Abstract
Development of control techniques for heating, ventilation and air conditioning (HVAC) systems to provide occupancy driven energy and comfort management has been an active area. In this study, we carried out the work on the balance between indoor environmental quality (IEQ) and energy consumption with low-dimensional linear models (LLM), artificial neural network (ANN) and contribution ratio of indoor climate (CRI) to provide support for HVAC control. In general, ventilation (pollutant) and temperature factors were both considered in the CFD simulation. Linear ventilation model (LVM) and linear temperature model (LTM) were employed to expand the CFD database. Then, combined with ANN, CRI and LLM, LLVM (low-dimensional linear ventilation model)-based ANN and LLTM (low-dimensional linear temperature model)-based CRI could rapidly predict the indoor environmental parameters. The evaluation indices were also defined to provide weightings between indoor environment and energy consumption. On this basis, the HVAC energy consumption caused by ventilation and air conditioning loads could be decreased by 50% and 16% respectively. This study will promote an intelligent HVAC control strategy for user comfort and HVAC energy conservation.
Experimental characterization of the impact of unsteady airflows on tracer gas measurement
Authors: Remion Gabriel , Moujalled Bassam , El Mankibi Mohamed 
Published: October 2019

Abstract
Natural ventilation induces several issues when trying to measure airflows. Low pressure differences that drive natural airflows are very sensitive. A small pressure drop introduced by an airflow-meter would significantly affect the flow pattern. Furthermore, for window aired buildings or rooms, the implementation of a protocol to characterize the flow through a window is practically hard to implement and often poorly reliable. For these reasons, tracer gas methods are widely used to measure natural airflows. They do not interfere with the flow path, as they do not require any other instruments than concentration sensors. The principle is to inject a tracer gas inside a chamber and to observe the evolution of the concentration of the tracer gas. The knowledge of the emission rate of the gas, as well as its concentration evolution allows describing the airflow.
Unfortunately, tracer gas methods are highly sensitive to the measurement noise, which is likely to be significant for concentration sensors. Most used methods, in the literature, use regression techniques to reduce the measurement noise. However, the regression implies steady airflows during the measurement, which should theoretically discard natural airflows. For lack of better methods, these techniques are often used in natural conditions, regardless of the variation of airflows. The present paper experimentally assess the impact of variable airflows on the accuracy of most common tracer gas methods, namely the constant injection and the concentration decay methods. The experiment was implemented in a laboratory cell, taking advantage of a controllable extract fan to simulate natural airflows, while allowing the direct measurement of the airflow in the extract duct. This value provides the reference value for the comparison of tracer gas methods results. Insights are also given, using signal-processing techniques to improve the reliability of tracer gas methods under variable airflows.
Passive ventilative cooling in residential buildings: a review
Authors: Song Ge , Ai Zhengtao , Zhang Guoqiang 
Published: October 2019

Abstract
The energy-saving potential of passive ventilative cooling has been underestimated, and the abuse of mechanical ventilation has resulted in significant energy waste in air quality. The use of large temperature difference between day and night; large temperature difference between indoor and outdoor during the transitional season; surface cold storage can greatly enhance the cooling effect of passive ventilation, reduce energy consumption and improve indoor air quality (IAQ). This paper analyzes and summarizes the research process of techniques and methods for realizing passive ventilation and cooling in residential buildings by using large temperature difference and accumulation of cold. The research results of the literature are mainly divided into two categories. On the one hand, the research methods and application characteristics of natural ventilation passive cooling technology formed by large temperature difference, which is dependent on climatic factors and residential conditions are described. On the other hand, the application environment and research technology of energy storage such as tunnel wind, which is based on the ventilation strategy and installation were described. Most of the research results show that the tunnel wind is relatively stable and comfortable, but the construction cost is too high, and the temperature difference is used to depend on the building category and climate environment. Passive ventilative cooling studies with focus on residential buildings are presented including both challenges and potential for improving building energy performance.
Including EAHX (earth-to-air heat exchanger) in early-design phases considering local bioclimatic potential and specific technological requirements
Authors: Chiesa Giacomo 
Published: October 2019

Abstract
Horizontal ground systems for ventilative cooling/heating, such as earth-to-air heat exchangers (EAHX), are a valid pre-heating and pre-cooling low-energy techniques to reduce the building energy consumptions for space heating and cooling. Nevertheless, the potential of these systems, such as others passive solutions, is local specific and need for devoted design methodologies. In particular, EAHXs need to be included in the design process as soon as possible in order to maximise the potentiality and allow for their integration – operational, technological and environmental issues. The paper will introduce a design methodology to define the local climatic potential of EAHX since the building programming phase by defining specific boundary conditions in well-known bioclimatic chart instruments. The effect of different design choices will be analysed for a set of three representative Italian locations. Furthermore, main functional, operational and environmental requirements will be discussed for this technical system. This analysis is based on the performance-drive approach to environmental and technological design – see for example UNI 8290-2:1983 – and is hence compatible with the technological-design practice and early-design consolidated methodologies.
Considerations for providing healthy, comfortable, energy-efficient whole-house mechanical ventilation during humid weather in near zero energy homes
Authors: Withers Charles 
Published: October 2019

Abstract
Whole-house mechanical ventilation (WHMV) is necessary for adequate ventilation in healthy near zero energy homes in most cases. Ventilation standards such as ASHRAE 62.2-2016 call for more ventilation than can be provided by natural ventilation in new homes built better than minimal building code requirements. A very troubling matter is that different studies in different climate locations have shown that a majority of WHMV evaluated in occupied homes has found them to be turned off, broken, or delivering too little ventilation when operational. Some homes with adequate ventilation may have increased potential for comfort complaints, moisture control issues, and even higher than expected energy usage. Higher energy usage will occur when supplemental dehumidification is needed. Balanced ventilation provided through a heat recovery ventilator or an energy recovery ventilator may be a good approach for many climate zones, however supplemental dehumidification needed for homes intended to maintain relative humidity around 50% during mild humid weather. Recent studies found that the highest efficiency variable air conditioning systems do not dehumidify as well as lower efficiency single stage systems, but some may be capable of very good dehumidification negating the need for costly supplemental dehumidification. This paper will use recent lab and field research studies to discuss details of issues that engineers and builders must consider to design WHMV with good potential of providing healthy, comfortable and energy-efficient ventilation.
Estimation and analysis of ventilation rates in schools in Indian context: IAQ and Indoor Environmental Quality
Authors: Jayakumar Sandhiya , Apte Michael G 
Published: October 2019

Abstract
The prolonged exposure to indoor air pollution may affect the health, comfort and performance of the occupants. Failing to address Indoor Air Quality (IAQ) problems may lead to short-term and long-term health problems. The health effects may vary for different individuals depending on factors like age and medical conditions, children being young and sensitive to the environment, are more susceptible to the same. The primary focus of this research is to estimate the ventilation rates in schools in Ahmedabad by using carbon dioxide (CO2) exhaled by the occupants, using steady state mass balance method. The air flow in the naturally ventilated classrooms was between 61.5 l/s per person to 15.6 l/s per person. The air flow in air-conditioned classrooms was 0.9 l/s per person and 1.0 l/s per person. The air flow in naturally ventilated classrooms are excessively high, more than meeting prescribed rates, while air flow in air-conditioned classrooms is far below the prescribed outdoor air rate per person as provided in ASHRAE 62.1: 2016 [1] and in the Bureau of Indian Standards [2].
Numerical modelling and experimental validation of pcm-to-air heat exchangers: application of ventilated building envelopes
Authors: Dardir Mohamed , El-Mankibi Mohamed , Haghighat Fariborz 
Published: October 2019

Abstract
The earlier applications of phase change material (PCM)-to-Air heat exchangers (PAHXs) reported the insufficient cooling charging energy due to system storage abilities, the profile of inlet air temperature, and the charging duration. This paper proposes a developed PAHX system for building envelope applications utilizing both convective and long-wave radiative heat transfer components. A 2D numerical model was proposed utilizing an apparent heat capacity method to represent the PCM latent thermal storage developing both convective and radiative thermal boundaries. The radiative component was developed to study the effect of the system exposure to the night-time sky during the PCM solidification period. The convective component was comprehensively developed mainly between the storage medium (PCM) and the air channel. A real-scale prototype was constructed for the whole model experimental validation. Field experiments were designed and conducted in the warm temperate climate of Lyon, France during summer. The validation criteria were proposed based on ASHRAE guideline 14. The results of the comparison between simulated data and experimentally obtained data showed that the system temperature was within the accepted range of the proposed criteria.
Ventilative cooling potential of buildings in Australia
Authors: Tartarini F , Fiorentini M , Ledo Gomis L , Cooper P 
Published: October 2019

Abstract
The demand for space cooling is the fastest growing end-use of electricity in buildings since many rely on the use of air-conditioners only to control the indoor climate. Ventilative cooling is a passive cooling technique, which involves the use of outdoor air to lower buildings’ indoor air temperature. In order to determine whether ventilative cooling may have the ability to reduce cooling loads, a detailed analysis of the local climate is needed. The aim of this study was to identify which Australian geographical regions have a suitable climate for the utilization of ventilative cooling techniques. The assessment of climatic potential for each geographic location was carried using two approaches: (i) a methodology which does not require detailed knowledge of the building characteristics, and; (ii) building performance simulation of a ‘typical’ Australian detached home. Results showed that the most populated Australian cities would benefit from the use of ventilative cooling techniques whereas the northern coastal region does not have a suitable climate.
Improving the Energy Performance Certificate recommendations’ accuracy for residential building through simple measurements of key inputs
Authors: Gonzalez-Caceres A , Arvid Vik T , Granheim P , fælth J P , Berg L 
Published: October 2019

AbstractThe Energy Performance Certificate (EPC) allows building users to be informed and aware of the quality of the buildings in terms of energy needs. Additionally, the EPC includes a future for existing buildings, which is the incorporation of a Recommendation list of Measures (RLMs) to improve their energy performance in a cost-effective way. Which have risen the question if this tool can provide trustful Cost-effective recommendations due despite the uses of standardized inputs. This study focuses on estimating the impact of using measure ventilation rate, heating set point and airtightness on the profitability of the recommendations. The study is based on common dwelling in Norway, comparing results obtained with a Building Performance Simulation Software, following the Norwegian standard for energy certification and with the uses of measured ventilation rate, airtightness and real heating set points. The results show that the performance gap can be reduced significantly just by adopting these inputs, increasing the confidence on the RLMs and reducing the uncertainty of the investment.
Key findings of IEA EBC Annex 68 - indoor air quality design and control in low energy residential buildings
Authors: Rode C , Abadie M , Qin M , Grunewald J , Kolarik J , Laverge J 
Published: October 2019

Abstract
The overall objective of the “Annex 68” Project, which belongs to the International Energy Agency’s “Energy in Buildings and Communities” Implementing Agreement, has been to develop the fundamental basis for optimal design and control strategies for good Indoor Air Quality (IAQ) in highly energy efficient residential buildings, and to disseminate this information in a practically applicable guide. The strategies shall facilitate the possibility to design and operate residential buildings with minimal energy use, while ensuring impeccable indoor climates.
The project completes its working phase by the end of spring 2019. The work has gathered laboratory and field data and developed new knowledge on pollution sources in buildings and how the transport mechanisms for the pollutants interact with heat, air and moisture conditions in materials and indoor zones. Furthermore, the project has assembled a set of contemporary models to simulate the combined heat, air, moisture and pollution conditions of buildings and their assemblies. The purpose has been to identify and describe amenable ways to optimize the provision of ventilation and air-conditioning. The paper gives an account of the project highlights.
A smoke exhausting method through a baffle-coupled shaft during tunnel fires
Authors: QianKun Hou , Weng Miao-cheng , liu Fang 
Published: October 2019

Abstract
In natural ventilation of road tunnel shaft, the plug-holing and boundary layer separation will decrease the efficiency. A new concept (baffle-coupled shaft) is put in place to solve the difficulty. Install baffle on both sides of the shaft (when the fire occurs upstream of the shaft, the baffle upstream of the shaft closes and the baffle downstream of the shaft opens), in the early stage of the fire, it can function as a smoke barrier. Numerical simulation was performed using the Fire Dynamic Simulation (Version 5.5.3). We use the mass flow of carbon monoxide discharged through the shaft as a basis for evaluating the efficiency of exhausting smoke. We could have determined that with the height of the baffle increasing, so does the efficiency of exhaust. In the investigation, the height of urban road tunnels is generally about 5 meters. So, it is appropriate to set the baffle height to 2m. Comprehensive car capacity, economy and cold air distributed, we can get a better He, that is in 1.0-1.5.
Influence of building airtightness on the internal thermal comfort and air quality in the single family house
Authors: Kisilewicz T , Nowak-Dzieszko K , Rojewska-Warchał M 
Published: October 2019

Abstract
The knowledge of the air exchange and building air-tightness is an indispensable source of information, both on the design and operation stage of the building use. Properly functioning ventilation system affects significantly internal thermal comfort and internal air quality. Infiltration of air determines the proper functioning of the gravitational ventilation, still the most commonly used system in Polish single-family housing. However, the most popular and easy to measure parameter: building airtightness (n50), does not specify the real air exchange in the actual climatic conditions. The real air flow rate may be determined with much more troublesome gas tracing method. Air flow rate, n, is in this method obtained from the decaying curve of gas concentration after injection of tracer gas into the building. This paper presents the results of the airtightness measurements conducted in a single family house with natural ventilation. Both, n
50 parameter and building air flow rate n have been measured. The results of the measurements were used as a model calibration tool in the annual computational simulations carried out in the Design Builder program for the Polish climatic conditions. Based on these simulations the authors determined the influence of building airtightness on the internal thermal comfort and the potential scenario of its control.
The effects of temperature and humidity on the VOC emission rate from dry building materials
Authors: Zhou Shan , Liu Hong , Ding Yong , Wu Yuxin 
Published: October 2019

Abstract
With the development of the economy and society, a wide variety of new building decoration and materials are widely used indoors. The concentration of pollutants such as formaldehyde, volatile organic compounds, benzene and ammonia in indoor air witnessed increase, causing increasingly serious indoor air pollution problems. Indoor building decoration materials are one of the main sources of indoor VOCs. In this paper, the emission law of VOCs in dry building materials with environmental conditions is studied. The environmental test cabin is used to test the formaldehyde and TVOC concentration released. The single factor variable method is used to study how different environmental conditions (temperature and relative humidity) affect the rate of formaldehyde and TVOC released from dry building materials. According to the results, increase of ambient temperature and relative humidity will promote the release of TVOC, which will affect its peak concentration and stable concentration, and the effect on formaldehyde release is more significant. This study clarified the release law of VOCs in artificial boards under different environmental conditions, which is of great significance for reducing indoor air pollutant levels and improving indoor air quality.
Comparative inhalation exposure/toxicology analysis of e-cigarette vapors with different puffing behaviors using PBPK-CSP-CFD approach
Authors: Kuga Kazuki , Ito Kazuhide 
Published: October 2019

Abstract
The overarching purpose of this study is to develop a numerical prediction method for assessment of human health risks caused from the inhalation exposure of various contaminants generated by electronic cigarettes (e-cigarettes). In this study, the inhalation exposure to contaminants, generated from e-cigarette smoking under two types of puffing behaviours was quantitatively estimated adapting a coupled physiologically based pharmacokinetic (PBPK)–computational fluid dynamics (CFD) model to a numerical respiratory tract model. Heterogeneous contaminants concentration distributions inside the respiratory tract were predicted through transient CFD simulations. For evaluating adsorption flux onto respiratory tissue surface, tissue surface contaminants concentrations of respiratory tract were calculated by using two concepts: partition coefficient between air-phase and tissue-phase and analogy of flux conservation. Contaminants concentration distributions inside the tissue were analyzed by using PBPK model. Through the coupled PBPK-CFD analyses, we indicated total fractions of contaminants inhaled from e-cigarette: (i) adsorbed onto tissue surface of respiratory tract, (ii) transported to deeper bronchial regions, and (iii) released into the indoor environment by exhalation. Basically, we indicated total respiratory uptake as a health risk factor of e-cigarette user and total amount of chemicals released into the indoor environment by exhalation as data which enable us to analyze second-hand and third-hand effects against non-user and indoor air quality.
Formaldehyde monitoring in office buildings located in tropical climates of India
Authors: Kiran Kumar D E V S , Jyothi Latha T , Suresh R , Arunvel T 
Published: October 2019

Abstract
Indoor air pollution is a result of complex phenomenon that occurs due to constantly changing interaction of various indoor and outdoor environmental factors. Volatile Organic Compounds (VOCs) are the major pollutants in air conditioned indoors, perhaps having a large subset of hazardous compounds. In this study, formaldehyde (HCHO) was monitored at 30 minute interval using portable photoelectric absorptiometric sensors along with comfort parameters like air temperature, relative humidity and air flow rate at six newly constructed or renovated office buildings located in composite, temperate and warm-humid climatic zones (in various parts of India). Results show that formaldehyde emissions exceeded the limits suggested by LEED guidelines (27 ppb) in all the buildings except in the ones where low emitting green interiors were used. Furniture and interior decorative work were found to be the primary sources of formaldehyde emission than other parameters. A logarithmic relationship (R2=0.65) was established between HCHO and respective age of the building/refurbished time. The analysis also presents that in a scenario of green interiors (low HCHO concentration) and the humidity levels above 60%, the trend of HCHO concentration with indoor moisture exhibits certain time delays in reaching equilibrium due to slow conditioning of HCHO molecules and indoor moisture. The study provides a rational analysis on HCHO emissions in Indian office buildings, which is important to understand possible sources and their effects on HCHO concentration in office indoors. The study data helps to implement required measures to control indoor humidity levels or necessary HCHO mitigation strategies during design and operation process of the air-conditioned office buildings.