Pub Date : 2020-09-11DOI: 10.1080/14733315.2020.1818445
D. Park, Seongju Chang
Abstract Even in case ventilation system is operating in optimal fashion, indoor air quality could be varied depending on the indoor contaminant release occasions. Thus, accurate and rapid identification of contaminant source locations in indoor environment is critical for occupants’ health as well as building safety and integrity. This study presented a novel method to locate indoor contaminant source using local mean residual-life-time (LMR). Based on the theoretical definition of LMR, a characteristic quantitative relationship between the LMR at source location and the contaminant concentration profile of a room was derived and assessed through two stages of studies: experimental and numerical explorations. In the experiments, by changing contaminant release location under limited condition, the LMR at the source location and the contaminant concentration profile of a test chamber were measured. Then, the outcomes were examined to verify whether the derived equation was established in the chamber. Computational Fluid Dynamics (CFD) technique was also used to make up for the experimental limitations. CFD simulations were carried out to analyze the validity of the equation in response to different release locations of the contaminant in a more complex physical environment by obtaining high-resolution information. Both experimental and numerical results showed that the presented equation was well established and could be used to locate indoor contaminant source even in non-ideal situation or in complicated spaces.
{"title":"Tracing indoor contaminant release location based on local mean residual-life-time of air","authors":"D. Park, Seongju Chang","doi":"10.1080/14733315.2020.1818445","DOIUrl":"https://doi.org/10.1080/14733315.2020.1818445","url":null,"abstract":"Abstract Even in case ventilation system is operating in optimal fashion, indoor air quality could be varied depending on the indoor contaminant release occasions. Thus, accurate and rapid identification of contaminant source locations in indoor environment is critical for occupants’ health as well as building safety and integrity. This study presented a novel method to locate indoor contaminant source using local mean residual-life-time (LMR). Based on the theoretical definition of LMR, a characteristic quantitative relationship between the LMR at source location and the contaminant concentration profile of a room was derived and assessed through two stages of studies: experimental and numerical explorations. In the experiments, by changing contaminant release location under limited condition, the LMR at the source location and the contaminant concentration profile of a test chamber were measured. Then, the outcomes were examined to verify whether the derived equation was established in the chamber. Computational Fluid Dynamics (CFD) technique was also used to make up for the experimental limitations. CFD simulations were carried out to analyze the validity of the equation in response to different release locations of the contaminant in a more complex physical environment by obtaining high-resolution information. Both experimental and numerical results showed that the presented equation was well established and could be used to locate indoor contaminant source even in non-ideal situation or in complicated spaces.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"66 1","pages":"135 - 157"},"PeriodicalIF":1.5,"publicationDate":"2020-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83464459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-09DOI: 10.1080/14733315.2020.1818375
A. Abdul Hamid, D. Johansson, Å. Wahlström, V. Fransson
Abstract A novel DCV-system controls the air-change rate for each apartment in multifamily buildings based on two indoor air parameters: 1) the moisture load (supply), and 2) volatile organic compounds. With a central fan, but decentralized control boxes placed outside each apartment, the system controls the air-change rate for each apartment. This paper’s main aim is to determine the potential of this DCV-system, through a case study, to: 1) achieve good IAQ, 2) handle the moisture loads appropriately, and 3) achieve good energy efficiency in multifamily buildings. Furthermore, the paper aims to assess the possibility to achieve good IAQ by validating the DCV-system’s VOC-controls through measurements of CO2 in apartments. Field measurements show that the system responds appropriately to apartment-specific loads, and that acceptable emission and moisture loads are achieved in most apartments in the case study. The impact that the system has on the energy use was assessed through calculations based on the field measurements. The calculations show that the DCV-system saves energy used for heating the supply-air by 86% in comparison to a mechanically balanced ventilation system without heat recovery, and 22% in comparison to the same system but with heat recovery.
{"title":"The impact of a DCV-system on the IAQ, energy use, and moisture safety in apartments - a case study","authors":"A. Abdul Hamid, D. Johansson, Å. Wahlström, V. Fransson","doi":"10.1080/14733315.2020.1818375","DOIUrl":"https://doi.org/10.1080/14733315.2020.1818375","url":null,"abstract":"Abstract A novel DCV-system controls the air-change rate for each apartment in multifamily buildings based on two indoor air parameters: 1) the moisture load (supply), and 2) volatile organic compounds. With a central fan, but decentralized control boxes placed outside each apartment, the system controls the air-change rate for each apartment. This paper’s main aim is to determine the potential of this DCV-system, through a case study, to: 1) achieve good IAQ, 2) handle the moisture loads appropriately, and 3) achieve good energy efficiency in multifamily buildings. Furthermore, the paper aims to assess the possibility to achieve good IAQ by validating the DCV-system’s VOC-controls through measurements of CO2 in apartments. Field measurements show that the system responds appropriately to apartment-specific loads, and that acceptable emission and moisture loads are achieved in most apartments in the case study. The impact that the system has on the energy use was assessed through calculations based on the field measurements. The calculations show that the DCV-system saves energy used for heating the supply-air by 86% in comparison to a mechanically balanced ventilation system without heat recovery, and 22% in comparison to the same system but with heat recovery.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"17 1","pages":"35 - 52"},"PeriodicalIF":1.5,"publicationDate":"2020-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86001415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-20DOI: 10.1080/14733315.2020.1786974
Loubna Qabbal, Z. Younsi, H. Naji
Abstract This study deals with the indoor air quality (IAQ) measured and perceived in a demonstration building via a smart sensor. The analysis subject targeted includes the following main air pollutants, viz., CO2, VOCs, formaldehyde, benzene, CO, PM2.5, and comfort parameters such as air temperature, and relative humidity. These were recorded during three campaigns. It turned out that the CO2 level was higher during the first occupation period, while measurements of other air pollutants were low. Besides, it turned out that the ventilation system could regulate control the airflow based on the CO2 concentrations only. However, this was upset occupants comfort.
{"title":"Indoor air quality investigation in a ventilated demonstrator building via a smart sensor","authors":"Loubna Qabbal, Z. Younsi, H. Naji","doi":"10.1080/14733315.2020.1786974","DOIUrl":"https://doi.org/10.1080/14733315.2020.1786974","url":null,"abstract":"Abstract This study deals with the indoor air quality (IAQ) measured and perceived in a demonstration building via a smart sensor. The analysis subject targeted includes the following main air pollutants, viz., CO2, VOCs, formaldehyde, benzene, CO, PM2.5, and comfort parameters such as air temperature, and relative humidity. These were recorded during three campaigns. It turned out that the CO2 level was higher during the first occupation period, while measurements of other air pollutants were low. Besides, it turned out that the ventilation system could regulate control the airflow based on the CO2 concentrations only. However, this was upset occupants comfort.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"49 1","pages":"89 - 104"},"PeriodicalIF":1.5,"publicationDate":"2020-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86089585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-06DOI: 10.1080/14733315.2020.1777654
Pavlos Toumpoulidis, A. Dimoudi, P. Kosmopoulos, S. Zoras
Abstract Over the last few decades, there is a clear target for reducingenergy needs in the building sector. The above objective can be achieved both by renovating the existing building stock and/or by constructing new buildings that will meet the characteristics of zero or nearly zero energy buildings. In order to construct or renovate a building into a zero or almost zero energy building, different passive, active and hybrid systems can be used. One such system is a solar air heater collector. The above system was installed in the south facade of the outdoor test cell (ZED-KIM (Zero Energy Demand – Kimmeria)), located at the Campus of the Environmental Engineering School, DUTH at Xanthi (Greece). In the present study, the monitoring results of the solar air heater collector and its contribution to cover the cooling load of a building will be presented. The system was monitored under real weather conditions for the period June 2017 to August 2017. This period was separated in two sub-periods. In the first one, the system operated as a solar air heater and with the appropriate modifications air from inside the test cell was passed through solar collector and hot air was rejected out. In the second sub-period, a ventilation inlet was added in the north facade of the test cell, and the system operated as a solar chimney. The heating load that rejected out in the first sub-period was 12 KWh and in the second sub-period was 58.5 KWh. In other terms the cooling load of the test cell was reduced by 70.5 KWh for the whole period of measurements. In addition the cooling load for the specific climate zone of Greece and for 20 m2 cooling space was 488 KWh so there was a reduction of 15 percent. Furthermore, it was noticed that the thermal efficiency of the system increased above 50 percent between 1st and 2nd sub period, with values being 16% and 34% respectively. Based on the above results, it is concluded that even in hot weather conditions prevailing in northern Greece, the use of a solar air heater collector with the appropriate modifications can cover, in a significant degree, the cooling load of a building and in conjunction with other passive and active systems it can lead at a nearly zero energy building.
{"title":"The contribution of a solar air heater collector to the cooling load in a building","authors":"Pavlos Toumpoulidis, A. Dimoudi, P. Kosmopoulos, S. Zoras","doi":"10.1080/14733315.2020.1777654","DOIUrl":"https://doi.org/10.1080/14733315.2020.1777654","url":null,"abstract":"Abstract Over the last few decades, there is a clear target for reducingenergy needs in the building sector. The above objective can be achieved both by renovating the existing building stock and/or by constructing new buildings that will meet the characteristics of zero or nearly zero energy buildings. In order to construct or renovate a building into a zero or almost zero energy building, different passive, active and hybrid systems can be used. One such system is a solar air heater collector. The above system was installed in the south facade of the outdoor test cell (ZED-KIM (Zero Energy Demand – Kimmeria)), located at the Campus of the Environmental Engineering School, DUTH at Xanthi (Greece). In the present study, the monitoring results of the solar air heater collector and its contribution to cover the cooling load of a building will be presented. The system was monitored under real weather conditions for the period June 2017 to August 2017. This period was separated in two sub-periods. In the first one, the system operated as a solar air heater and with the appropriate modifications air from inside the test cell was passed through solar collector and hot air was rejected out. In the second sub-period, a ventilation inlet was added in the north facade of the test cell, and the system operated as a solar chimney. The heating load that rejected out in the first sub-period was 12 KWh and in the second sub-period was 58.5 KWh. In other terms the cooling load of the test cell was reduced by 70.5 KWh for the whole period of measurements. In addition the cooling load for the specific climate zone of Greece and for 20 m2 cooling space was 488 KWh so there was a reduction of 15 percent. Furthermore, it was noticed that the thermal efficiency of the system increased above 50 percent between 1st and 2nd sub period, with values being 16% and 34% respectively. Based on the above results, it is concluded that even in hot weather conditions prevailing in northern Greece, the use of a solar air heater collector with the appropriate modifications can cover, in a significant degree, the cooling load of a building and in conjunction with other passive and active systems it can lead at a nearly zero energy building.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"20 1","pages":"265 - 275"},"PeriodicalIF":1.5,"publicationDate":"2020-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87021047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-06DOI: 10.1080/14733315.2020.1777015
Natalia Lastovets, K. Sirén, R. Kosonen, J. Jokisalo, S. Kilpeläinen
Abstract An accurate temperature gradient calculation is essential for displacement ventilation (DV) system design since it directly relates to thecalculation of the required supply airflow rate. Inaccurate temperature prediction can cause poor thermal comfort and wrong sizing of the ventilation and cooling systems. A heat balance-based method is usually applied in displacement ventilation (DV) design when overheating is the primary indoor climate concern. The temperature gradient in DV systems is usually calculated with lumped-parameter nodal models. Several simplified nodal models were developed and implemented in the various building simulation software to estimate the temperature stratification in rooms with DV. Recent studies reveal that the multi-nodal models provide the most accurate temperature gradient prediction. However, the majority of dynamic calculation methods assumes either complete mixing of zone air or linearised temperature gradient. The present study introduces the dynamic temperature gradient model for DV and investigates the effect of thermal mass on the temperature stratification. The model was validated with the experimental results of a lecture room with displacement ventilation. The room air temperature measurements were conducted during three weeks at 20 different heights. The supply air temperature and occupancy rate were recorded during each scheduled lecture. The developed dynamic nodal model is able to calculate the air temperatures in the occupied zone accurately. The effect of the thermal mass and changing heat gains on the room air temperature stratification is analysed for the lecture room with DV.
{"title":"Dynamic performance of displacement ventilation in a lecture hall","authors":"Natalia Lastovets, K. Sirén, R. Kosonen, J. Jokisalo, S. Kilpeläinen","doi":"10.1080/14733315.2020.1777015","DOIUrl":"https://doi.org/10.1080/14733315.2020.1777015","url":null,"abstract":"Abstract An accurate temperature gradient calculation is essential for displacement ventilation (DV) system design since it directly relates to thecalculation of the required supply airflow rate. Inaccurate temperature prediction can cause poor thermal comfort and wrong sizing of the ventilation and cooling systems. A heat balance-based method is usually applied in displacement ventilation (DV) design when overheating is the primary indoor climate concern. The temperature gradient in DV systems is usually calculated with lumped-parameter nodal models. Several simplified nodal models were developed and implemented in the various building simulation software to estimate the temperature stratification in rooms with DV. Recent studies reveal that the multi-nodal models provide the most accurate temperature gradient prediction. However, the majority of dynamic calculation methods assumes either complete mixing of zone air or linearised temperature gradient. The present study introduces the dynamic temperature gradient model for DV and investigates the effect of thermal mass on the temperature stratification. The model was validated with the experimental results of a lecture room with displacement ventilation. The room air temperature measurements were conducted during three weeks at 20 different heights. The supply air temperature and occupancy rate were recorded during each scheduled lecture. The developed dynamic nodal model is able to calculate the air temperatures in the occupied zone accurately. The effect of the thermal mass and changing heat gains on the room air temperature stratification is analysed for the lecture room with DV.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"22 1","pages":"204 - 214"},"PeriodicalIF":1.5,"publicationDate":"2020-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77790596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-02DOI: 10.1080/14733315.2019.1600815
Sherzad Hawendi, Shian Gao, A. Ahmed
Abstract Natural ventilation is the most energy-efficient method by which to passively cool a building, reducing the energy consumption, and improving the thermal comfort and indoor air quality. However, designing buildings using cross-ventilation is far more complicated than mere mechanical design due to the indoor and outdoor parameters in addition to the building configurations. The authors have previously reported that the indoor thermal comfort in an isolated family house is affected significantly by the outdoor conditions; the current study, however, focusses on the impact of heat loads and furniture on the indoor thermal comfort. In this work, The Computational Fluid Dynamics (CFD) approach was employed with a coupled indoor-outdoor simulation. The results showed that the heat dissipated from electrical appliances found in daily life only have a small effect on the thermal comfort indices at both the seated and standing levels because they use only relatively small amounts of energy, whereas these indices are increased remarkably at these two levels when an additional heat source was operated in conjunction with these appliances. In addition, no significant differences between the empty building and the furniture-filled building were observed at the two levels when comparing the air velocity, temperature and thermal comfort indices.
{"title":"Effect of heat loads and furniture on the thermal comfort of an isolated family house under a naturally ventilated environment","authors":"Sherzad Hawendi, Shian Gao, A. Ahmed","doi":"10.1080/14733315.2019.1600815","DOIUrl":"https://doi.org/10.1080/14733315.2019.1600815","url":null,"abstract":"Abstract Natural ventilation is the most energy-efficient method by which to passively cool a building, reducing the energy consumption, and improving the thermal comfort and indoor air quality. However, designing buildings using cross-ventilation is far more complicated than mere mechanical design due to the indoor and outdoor parameters in addition to the building configurations. The authors have previously reported that the indoor thermal comfort in an isolated family house is affected significantly by the outdoor conditions; the current study, however, focusses on the impact of heat loads and furniture on the indoor thermal comfort. In this work, The Computational Fluid Dynamics (CFD) approach was employed with a coupled indoor-outdoor simulation. The results showed that the heat dissipated from electrical appliances found in daily life only have a small effect on the thermal comfort indices at both the seated and standing levels because they use only relatively small amounts of energy, whereas these indices are increased remarkably at these two levels when an additional heat source was operated in conjunction with these appliances. In addition, no significant differences between the empty building and the furniture-filled building were observed at the two levels when comparing the air velocity, temperature and thermal comfort indices.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"2 1","pages":"163 - 188"},"PeriodicalIF":1.5,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75447493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract For the interchange tunnel fire, the structural features of bifurcation and convergence will make the smoke movement characteristics different from the traditional single tube tunnel fire. This paper carried out numerical simulations by ANSYS Fluent to study the smoke movement characteristics in large scale interchange tunnel fire. Different heat release rates, ventilation velocities and bifurcation angles were considered to analyze the carbon monoxide concentration distribution and critical velocity. Results showed that the CO concentration decreased as the ventilation velocity increased and the variation gradient of CO concentration decreased as the distance away from the fire increased. The CO concentration distribution was symmetrical about the longitudinal centerline of the tunnel when the fire located far away from the bifurcation point, and the asymmetric distribution phenomenon disappeared while the fire located at the bifurcation point. In addition, the critical velocity increased as the bifurcation angle increased while the fire located at the bifurcation point. However, the bifurcation angle had no direct impact on the critical velocity when the fire located far away from the bifurcation point.
{"title":"Study on the smoke movement characteristics in large scale interchange tunnel fire","authors":"Tao Li, Longfei Chen, Yu-chun Zhang, Wei-ping Ma, Chong Yang, Fengju Shang","doi":"10.1080/14733315.2019.1693174","DOIUrl":"https://doi.org/10.1080/14733315.2019.1693174","url":null,"abstract":"Abstract For the interchange tunnel fire, the structural features of bifurcation and convergence will make the smoke movement characteristics different from the traditional single tube tunnel fire. This paper carried out numerical simulations by ANSYS Fluent to study the smoke movement characteristics in large scale interchange tunnel fire. Different heat release rates, ventilation velocities and bifurcation angles were considered to analyze the carbon monoxide concentration distribution and critical velocity. Results showed that the CO concentration decreased as the ventilation velocity increased and the variation gradient of CO concentration decreased as the distance away from the fire increased. The CO concentration distribution was symmetrical about the longitudinal centerline of the tunnel when the fire located far away from the bifurcation point, and the asymmetric distribution phenomenon disappeared while the fire located at the bifurcation point. In addition, the critical velocity increased as the bifurcation angle increased while the fire located at the bifurcation point. However, the bifurcation angle had no direct impact on the critical velocity when the fire located far away from the bifurcation point.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"54 1","pages":"224 - 232"},"PeriodicalIF":1.5,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85321806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-02DOI: 10.1080/14733315.2019.1615220
Mohsen M. Barsim, M. Bassily, H. El-Batsh, Yaser A. Rihan, M. M. Sherif
Abstract In this paper, the capability of Froude scaling modeling to replicate the fire dynamics in full-scale Murcia Atrium Fires tests equipped with natural and transient forced ventilation was investigated experimentally and numerically by using a 2:27 physical Scale Down Model (SDM) of the full-scale Atrium and CFX-Ansys16.2, respectively. Five SDM experiments were conducted using different heptane fire capacities located at the center of the floor. Two different turbulence models were used for simulation i.e. Shear Stress Transport and k − ε. Experimental results of the SDM and full-scale atrium fire tests were compared with those predicted for SDM through the preservation of the Froude number to cover the gap in experimental facts and scientific understanding. This study focused primarily on the transient temperatures at near and far fire fields and the descending smoke layer. The predicted velocity and visibility were assessed. This study demonstrated that Froude scaling modelling is acceptable from a threshold of greater than 50% of the full-scale.
{"title":"Froude scaling modeling in an Atrium Fire equipped with natural and transient forced ventilation","authors":"Mohsen M. Barsim, M. Bassily, H. El-Batsh, Yaser A. Rihan, M. M. Sherif","doi":"10.1080/14733315.2019.1615220","DOIUrl":"https://doi.org/10.1080/14733315.2019.1615220","url":null,"abstract":"Abstract In this paper, the capability of Froude scaling modeling to replicate the fire dynamics in full-scale Murcia Atrium Fires tests equipped with natural and transient forced ventilation was investigated experimentally and numerically by using a 2:27 physical Scale Down Model (SDM) of the full-scale Atrium and CFX-Ansys16.2, respectively. Five SDM experiments were conducted using different heptane fire capacities located at the center of the floor. Two different turbulence models were used for simulation i.e. Shear Stress Transport and k − ε. Experimental results of the SDM and full-scale atrium fire tests were compared with those predicted for SDM through the preservation of the Froude number to cover the gap in experimental facts and scientific understanding. This study focused primarily on the transient temperatures at near and far fire fields and the descending smoke layer. The predicted velocity and visibility were assessed. This study demonstrated that Froude scaling modelling is acceptable from a threshold of greater than 50% of the full-scale.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"82 1","pages":"201 - 223"},"PeriodicalIF":1.5,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75904215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.1080/14733315.2020.1777003
G. Braun, W. Zeiler
Abstract The indoor air quality is important for the well-being of humans, especially in the case of young babies. This research focuses on the air qualityinside a crib with sleeping infants. The effects of different sleeping positions of the baby on the air quality within the crib were studied by measurements on modelled setup. The breathing of an infant was simulated by means of a baby doll which had a breathing device: a intermitted supply of air mixed with CO2 through a tube in the lips of the baby doll. For different sleeping positions, the effects on the CO2 concentration inside the baby bed were measured and compared with the background CO2-level in the sleeping quarter. The results showed an increased CO2 concentration (up to 4 times) depending on the sleeping position of the infant.
{"title":"CO2-concentration of the surrounding air of sleeping infants inside a crib","authors":"G. Braun, W. Zeiler","doi":"10.1080/14733315.2020.1777003","DOIUrl":"https://doi.org/10.1080/14733315.2020.1777003","url":null,"abstract":"Abstract The indoor air quality is important for the well-being of humans, especially in the case of young babies. This research focuses on the air qualityinside a crib with sleeping infants. The effects of different sleeping positions of the baby on the air quality within the crib were studied by measurements on modelled setup. The breathing of an infant was simulated by means of a baby doll which had a breathing device: a intermitted supply of air mixed with CO2 through a tube in the lips of the baby doll. For different sleeping positions, the effects on the CO2 concentration inside the baby bed were measured and compared with the background CO2-level in the sleeping quarter. The results showed an increased CO2 concentration (up to 4 times) depending on the sleeping position of the infant.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"47 1","pages":"161 - 171"},"PeriodicalIF":1.5,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76520748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-30DOI: 10.1080/14733315.2020.1777012
Klaas De Jonge, J. Laverge
Abstract With increasing building airtightness, the design of an adequate ventilation system gains importance. The first generation of ventilation systems, based on continuous supply of the nominal airflow rate, are now being replaced by demand controlled ventilation (DCV). These systems, often H2O and/or CO2 controlled, typically do not take into account the emissions of volatile organic compounds (VOCs) to the indoor environment. A small, airtight, zero energy building that has been designed as the Belgian submission to the international Solar Decathlon competition (2011) was rebuilt afterwards in Ostend, Belgium. This building will be used as test facility for the development and validation of a holistic VOC source model. In this study, results are obtained from thermal, airflow and contaminant simulation models of the test facility to check the potential of this facility for research concerning VOCs. The different models and modeling assumptions are discussed. A dynamic VOC source model, derived from literature, is used as proxy to obtain possible VOC concentrations. The results show an important influence of temperature and humidity on the indoor VOC levels with VOC concentrations exceeding health guidelines. It is therefore important to design DCV systems and controls taking into account possible elevated VOC levels and while doing so, incorporate the dynamic behavior (influence of temperature and humidity) of the VOC emissions.
{"title":"Modeling dynamic behavior of volatile organic compounds in a zero energy building","authors":"Klaas De Jonge, J. Laverge","doi":"10.1080/14733315.2020.1777012","DOIUrl":"https://doi.org/10.1080/14733315.2020.1777012","url":null,"abstract":"Abstract With increasing building airtightness, the design of an adequate ventilation system gains importance. The first generation of ventilation systems, based on continuous supply of the nominal airflow rate, are now being replaced by demand controlled ventilation (DCV). These systems, often H2O and/or CO2 controlled, typically do not take into account the emissions of volatile organic compounds (VOCs) to the indoor environment. A small, airtight, zero energy building that has been designed as the Belgian submission to the international Solar Decathlon competition (2011) was rebuilt afterwards in Ostend, Belgium. This building will be used as test facility for the development and validation of a holistic VOC source model. In this study, results are obtained from thermal, airflow and contaminant simulation models of the test facility to check the potential of this facility for research concerning VOCs. The different models and modeling assumptions are discussed. A dynamic VOC source model, derived from literature, is used as proxy to obtain possible VOC concentrations. The results show an important influence of temperature and humidity on the indoor VOC levels with VOC concentrations exceeding health guidelines. It is therefore important to design DCV systems and controls taking into account possible elevated VOC levels and while doing so, incorporate the dynamic behavior (influence of temperature and humidity) of the VOC emissions.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"1 1","pages":"193 - 203"},"PeriodicalIF":1.5,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87346335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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