Pub Date : 2020-06-30DOI: 10.1080/14733315.2020.1777018
L. Scheuring, B. Weller
Abstract Guaranteeing high indoor air quality and high degree of usersatisfaction at the same time is one of the challenges when improving the energy efficiency, namely the energy consumption, of a building. Current non-residential buildings mainly use mechanical ventilation systems to ensure high air quality. Natural ventilation can be an alternative regarding to lower maintenance costs and the psychological feeling of fresh air. Present natural ventilated buildings pose the risk of higher energy demand and less indoor air quality due to user’s behaviour. Controlled natural ventilation based on indoor CO2 concentration and room air temperature is needed. However, the energy efficiency of a control strategy highly depends on climate zone and control parameters. This paper aims to explore the impact of different control strategies on the energy efficiency of an operable louver window. The analyses are done for yearly results and then for each month individual to clarify the effect of monthly varying control strategies. For the analysis EnergyPlus as a building energy simulation tool and for the natural ventilation in specific the EnergyPlus Design Flow Rate method is used. In the simulation four window opening strategies based on CO2 concentration and one simple intake/exhaust mechanical ventilation system were tested in Mediterranean, subtropical and moderate climate zone. The highest impact on energy efficiency and thermal comfort was seen at the cold months in the moderate climate. Long window opening strategies cannot be implemented because of a high thermal discomfort. In the hot months in the Mediterranean and subtropical climate an impact of ventilation strategies are seen as well. Only at moderate conditions no major differences in the natural ventilation strategies were observed. When comparing the natural ventilation conditions to mechanical ventilation major differences were found. In almost all climate conditions natural ventilation outperformed the mechanical ventilation. Only in winter months in the moderate climate mechanical ventilation outperforms natural ventilation.
{"title":"An investigation of ventilation control strategies for louver windows in different climate zones","authors":"L. Scheuring, B. Weller","doi":"10.1080/14733315.2020.1777018","DOIUrl":"https://doi.org/10.1080/14733315.2020.1777018","url":null,"abstract":"Abstract Guaranteeing high indoor air quality and high degree of usersatisfaction at the same time is one of the challenges when improving the energy efficiency, namely the energy consumption, of a building. Current non-residential buildings mainly use mechanical ventilation systems to ensure high air quality. Natural ventilation can be an alternative regarding to lower maintenance costs and the psychological feeling of fresh air. Present natural ventilated buildings pose the risk of higher energy demand and less indoor air quality due to user’s behaviour. Controlled natural ventilation based on indoor CO2 concentration and room air temperature is needed. However, the energy efficiency of a control strategy highly depends on climate zone and control parameters. This paper aims to explore the impact of different control strategies on the energy efficiency of an operable louver window. The analyses are done for yearly results and then for each month individual to clarify the effect of monthly varying control strategies. For the analysis EnergyPlus as a building energy simulation tool and for the natural ventilation in specific the EnergyPlus Design Flow Rate method is used. In the simulation four window opening strategies based on CO2 concentration and one simple intake/exhaust mechanical ventilation system were tested in Mediterranean, subtropical and moderate climate zone. The highest impact on energy efficiency and thermal comfort was seen at the cold months in the moderate climate. Long window opening strategies cannot be implemented because of a high thermal discomfort. In the hot months in the Mediterranean and subtropical climate an impact of ventilation strategies are seen as well. Only at moderate conditions no major differences in the natural ventilation strategies were observed. When comparing the natural ventilation conditions to mechanical ventilation major differences were found. In almost all climate conditions natural ventilation outperformed the mechanical ventilation. Only in winter months in the moderate climate mechanical ventilation outperforms natural ventilation.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"52 1","pages":"226 - 235"},"PeriodicalIF":1.5,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84683424","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: 10.1080/14733315.2020.1777009
Justin Berquist, C. Banister, Dennis Krys
Abstract A demonstration house was previously built and commissioned in Iqaluit, Nunavut, Canada. The purpose of the overall effort is to develop and integrate technologies and evaluate the performance of a high-performance building located in the Canadian Arctic, while considering the unique social, economic, and logistical challenges associated with its remote location. Previous work consisted of monitoring and reporting on the energy use from heating between April 2016 and April 2017. The purpose of this next stage of research is to contribute experimental data of the prototype demand-controlled residential ventilation system in the extremely cold climate of Iqaluit, where the average annual outdoor temperature is approximately −9 °C. This paper outlines the development, implementation and monitoring of the carbon dioxide-based demand-controlled heat recovery ventilation system that took place between April 2017 and April 2019. The system was equipped with two electric preheaters to ensure that frost build-up did not occur in the heat recovery ventilator (HRV) and adequate ventilation could be maintained according to the demand. An electric heater was included after the HRV to control the supply air temperature. Between December 2018 and February 2019 the electricity consumption of the HRV, preheaters, and supply air heater were measured for the lowest ventilation rate of the system, 15.5 L/s. Pertinent temperatures in the ventilation system were also monitored to enable assessment of the system’s performance. A comparison of the sensible recovery efficiency (SRE) of the HRV and overall system is presented. Experiments displayed that, on average, the SRE of the HRV and system were 72% and 35%, respectively. The total energy use of the ventilation system was 390 kWh over the two months, which translates to 6.30 kWh/day, an energy use intensity of 0.27 kWh/m2/day, or 12.25 Wh/m3 of outdoor air supplied.
{"title":"Performance of an advanced heat recovery ventilation system in the Canadian Arctic","authors":"Justin Berquist, C. Banister, Dennis Krys","doi":"10.1080/14733315.2020.1777009","DOIUrl":"https://doi.org/10.1080/14733315.2020.1777009","url":null,"abstract":"Abstract A demonstration house was previously built and commissioned in Iqaluit, Nunavut, Canada. The purpose of the overall effort is to develop and integrate technologies and evaluate the performance of a high-performance building located in the Canadian Arctic, while considering the unique social, economic, and logistical challenges associated with its remote location. Previous work consisted of monitoring and reporting on the energy use from heating between April 2016 and April 2017. The purpose of this next stage of research is to contribute experimental data of the prototype demand-controlled residential ventilation system in the extremely cold climate of Iqaluit, where the average annual outdoor temperature is approximately −9 °C. This paper outlines the development, implementation and monitoring of the carbon dioxide-based demand-controlled heat recovery ventilation system that took place between April 2017 and April 2019. The system was equipped with two electric preheaters to ensure that frost build-up did not occur in the heat recovery ventilator (HRV) and adequate ventilation could be maintained according to the demand. An electric heater was included after the HRV to control the supply air temperature. Between December 2018 and February 2019 the electricity consumption of the HRV, preheaters, and supply air heater were measured for the lowest ventilation rate of the system, 15.5 L/s. Pertinent temperatures in the ventilation system were also monitored to enable assessment of the system’s performance. A comparison of the sensible recovery efficiency (SRE) of the HRV and overall system is presented. Experiments displayed that, on average, the SRE of the HRV and system were 72% and 35%, respectively. The total energy use of the ventilation system was 390 kWh over the two months, which translates to 6.30 kWh/day, an energy use intensity of 0.27 kWh/m2/day, or 12.25 Wh/m3 of outdoor air supplied.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"16 1","pages":"183 - 192"},"PeriodicalIF":1.5,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84398834","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: 10.1080/14733315.2020.1777029
Irene Poza-Casado, Alberto Meiss, M. Padilla-Marcos, Jesús Feijó-Muñoz
Abstract Addressing the airtightness of the building envelope is key to achieve thermal comfort, good performance ofventilation systems and to avoid excessive energy consumption. Previous studies have estimated an energy impact of infiltration on the heating demand between 2 and 20 kW h/(m2 y) in regions with temperate climates. In Spain, this issue has not yet been addressed in depth. This study aims to assess the energy impact of uncontrolled airflows through the envelope in residential buildings in Spain. For this purpose, airtightness results of more than 400 blower door tests have been analysed. Multi-family and single-family dwellings built in several periods and located in nine regions with different climate characteristics have been studied. Infiltration was found to have an energy impact in the range 2.43–19.07 kW h/(m2 y) for the heating demand, whereas it is not so significant regarding the cooling demand. The obtained results show great potential for energy saving in the country.
{"title":"Airtightness and energy impact of air infiltration in residential buildings in Spain","authors":"Irene Poza-Casado, Alberto Meiss, M. Padilla-Marcos, Jesús Feijó-Muñoz","doi":"10.1080/14733315.2020.1777029","DOIUrl":"https://doi.org/10.1080/14733315.2020.1777029","url":null,"abstract":"Abstract Addressing the airtightness of the building envelope is key to achieve thermal comfort, good performance ofventilation systems and to avoid excessive energy consumption. Previous studies have estimated an energy impact of infiltration on the heating demand between 2 and 20 kW h/(m2 y) in regions with temperate climates. In Spain, this issue has not yet been addressed in depth. This study aims to assess the energy impact of uncontrolled airflows through the envelope in residential buildings in Spain. For this purpose, airtightness results of more than 400 blower door tests have been analysed. Multi-family and single-family dwellings built in several periods and located in nine regions with different climate characteristics have been studied. Infiltration was found to have an energy impact in the range 2.43–19.07 kW h/(m2 y) for the heating demand, whereas it is not so significant regarding the cooling demand. The obtained results show great potential for energy saving in the country.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"21 1","pages":"258 - 264"},"PeriodicalIF":1.5,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84340094","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: 10.1080/14733315.2020.1777020
M. Prignon, A. Dawans, G. van Moeseke
Abstract Multiple authors stated that, when performing fan pressurization test, Ordinary Least Square (OLS) method should not be used as a regression technique anymore. However, alternative methods require first to quantify components of uncertainty in pressure and air flow rate measurements. This work aims at quantifying the uncertainty in zero-flow pressure approximation, which is mainly due to short-term fluctuation of wind speed and direction. This has been done by statistically analysing the uncertainty indicator of 40 zero-flow pressure tests performed on 30 different units on eight different sites in Brussels. First, the analysis showed that this uncertainty could be reduced by increasing the period of measurement used to compute zero-flow pressure approximation. Second, it shows that the standard deviation of zero-flow pressure measurements was the variable with the most significant impact on the quality of the zero-flow pressure approximation. Third, it provides three different linear models to predict uncertainty as a function of different variables. This study experienced some limitations due to the available sample of tested units. These limitations lead to important further work: the validation of the model on another sample of buildings and its adaptation if needed. Further work should also focus on integrating these results on the uncertainty in envelope pressure measurements and on the uncertainty in airtightness estimation of the building.
{"title":"Quantification of uncertainty in zero-flow pressure approximation","authors":"M. Prignon, A. Dawans, G. van Moeseke","doi":"10.1080/14733315.2020.1777020","DOIUrl":"https://doi.org/10.1080/14733315.2020.1777020","url":null,"abstract":"Abstract Multiple authors stated that, when performing fan pressurization test, Ordinary Least Square (OLS) method should not be used as a regression technique anymore. However, alternative methods require first to quantify components of uncertainty in pressure and air flow rate measurements. This work aims at quantifying the uncertainty in zero-flow pressure approximation, which is mainly due to short-term fluctuation of wind speed and direction. This has been done by statistically analysing the uncertainty indicator of 40 zero-flow pressure tests performed on 30 different units on eight different sites in Brussels. First, the analysis showed that this uncertainty could be reduced by increasing the period of measurement used to compute zero-flow pressure approximation. Second, it shows that the standard deviation of zero-flow pressure measurements was the variable with the most significant impact on the quality of the zero-flow pressure approximation. Third, it provides three different linear models to predict uncertainty as a function of different variables. This study experienced some limitations due to the available sample of tested units. These limitations lead to important further work: the validation of the model on another sample of buildings and its adaptation if needed. Further work should also focus on integrating these results on the uncertainty in envelope pressure measurements and on the uncertainty in airtightness estimation of the building.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"29 1","pages":"248 - 257"},"PeriodicalIF":1.5,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82081665","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: 10.1080/14733315.2020.1777017
A. Leconte, Clément Lafféter, T. Fritsch, N. Giordano, J. Escaich, Ophélie Ouvrier-Bonnaz
Abstract This study aims to experimentally evaluate the influence of the combination of a supply only ventilation, called here positive input ventilation, and innovative active air vents on the Indoor Air Quality of a house. The positive input ventilation draws fresh air from the outside, filters and pre-heats it before supplying it to living areas. Active air vents are small motorised dampers set up in the upper part of windows able to move according to local pollutants measurements or to the measurements of other active air vents in the house. This combination is expected to improve the Indoor Air Quality by increasing efficiently the air change rate of a room when it is too polluted. The goal of the tests presented in this paper is to evaluate quantitatively the air change rate in a real size environment. To do so, a positive input ventilation and active air vents are set up in an experimental house. The tests were carried out in 3 different rooms. For each room, the air change rate is evaluated for different configurations of the combination. CO2 is used as a trace gas to evaluate the air change rate. Results are promising and show that the studied combination allows a significant of the air change rate of each room. An appropriate Demand Control Ventilation strategy based on the sensors of each active air vents and the communication between all the devices would thus lead to an efficient while simple improvement in the use of a positive input ventilation system.
{"title":"Experimental study of the combination of a positive input ventilation and active air vents on the air change rates of a house","authors":"A. Leconte, Clément Lafféter, T. Fritsch, N. Giordano, J. Escaich, Ophélie Ouvrier-Bonnaz","doi":"10.1080/14733315.2020.1777017","DOIUrl":"https://doi.org/10.1080/14733315.2020.1777017","url":null,"abstract":"Abstract This study aims to experimentally evaluate the influence of the combination of a supply only ventilation, called here positive input ventilation, and innovative active air vents on the Indoor Air Quality of a house. The positive input ventilation draws fresh air from the outside, filters and pre-heats it before supplying it to living areas. Active air vents are small motorised dampers set up in the upper part of windows able to move according to local pollutants measurements or to the measurements of other active air vents in the house. This combination is expected to improve the Indoor Air Quality by increasing efficiently the air change rate of a room when it is too polluted. The goal of the tests presented in this paper is to evaluate quantitatively the air change rate in a real size environment. To do so, a positive input ventilation and active air vents are set up in an experimental house. The tests were carried out in 3 different rooms. For each room, the air change rate is evaluated for different configurations of the combination. CO2 is used as a trace gas to evaluate the air change rate. Results are promising and show that the studied combination allows a significant of the air change rate of each room. An appropriate Demand Control Ventilation strategy based on the sensors of each active air vents and the communication between all the devices would thus lead to an efficient while simple improvement in the use of a positive input ventilation system.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"52 1","pages":"215 - 225"},"PeriodicalIF":1.5,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84952539","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 : 2020-06-19DOI: 10.1080/14733315.2020.1777019
A. Mahdavi, H. Teufl, C. Berger
Abstract Buildings typically are expected to provide their inhabitants with the opportunity to influence the indoor environment using various control devices. These include, for example, windows, luminaires, radiators, and shading elements. The quality and adequacy of the indoor environment is thus dependent on the availability and effectiveness of such devices. There is arguably a lack of generally agreed-upon evaluation procedures for this aspect of buildings’ indoor environment, namely its controllability by building users, or – in the terminology of Human Ecology – its “ecological valency”. In this context, the present contribution explores the possibility to specify buildings’ ecological valency in a systematic and reproducible manner. Toward this end, first appropriate theoretical foundations for this purpose are explored and previous related efforts are briefly reviewed. Subsequently, a specific approach toward an ecological valency evaluation method is presented. As part of this approach, five main categories of control devices are documented in various rooms of a building, including windows, shading, lights, heating and cooling systems. Whereas, the first part of this method deals with the basic availability of these control devices and elements, the second part looks at their spatial distribution, effectiveness (both objective and subjective), interface quality (to support user interaction), and ecological quality. The presented evaluation method is tested for six different rooms of an office area in an educational building in Vienna, Austria. Thirty participants independently evaluated this area based on the proposed method and associated protocol. The results point to high degree of congruence between the evaluation results of different participants while judging the principle availability and typology of the control devices. Higher variation was observed in the evaluation of the quality of devices and their interfaces. As a whole, the results suggest that methods similar to the one presented in this contribution may indeed provide an opportunity to extend building performance evaluation procedures beyond energy and cost criteria so as to cover aspects pertaining to user control and satisfaction.
{"title":"A structured approach to the evaluation of indoor environments’ecological valency","authors":"A. Mahdavi, H. Teufl, C. Berger","doi":"10.1080/14733315.2020.1777019","DOIUrl":"https://doi.org/10.1080/14733315.2020.1777019","url":null,"abstract":"Abstract Buildings typically are expected to provide their inhabitants with the opportunity to influence the indoor environment using various control devices. These include, for example, windows, luminaires, radiators, and shading elements. The quality and adequacy of the indoor environment is thus dependent on the availability and effectiveness of such devices. There is arguably a lack of generally agreed-upon evaluation procedures for this aspect of buildings’ indoor environment, namely its controllability by building users, or – in the terminology of Human Ecology – its “ecological valency”. In this context, the present contribution explores the possibility to specify buildings’ ecological valency in a systematic and reproducible manner. Toward this end, first appropriate theoretical foundations for this purpose are explored and previous related efforts are briefly reviewed. Subsequently, a specific approach toward an ecological valency evaluation method is presented. As part of this approach, five main categories of control devices are documented in various rooms of a building, including windows, shading, lights, heating and cooling systems. Whereas, the first part of this method deals with the basic availability of these control devices and elements, the second part looks at their spatial distribution, effectiveness (both objective and subjective), interface quality (to support user interaction), and ecological quality. The presented evaluation method is tested for six different rooms of an office area in an educational building in Vienna, Austria. Thirty participants independently evaluated this area based on the proposed method and associated protocol. The results point to high degree of congruence between the evaluation results of different participants while judging the principle availability and typology of the control devices. Higher variation was observed in the evaluation of the quality of devices and their interfaces. As a whole, the results suggest that methods similar to the one presented in this contribution may indeed provide an opportunity to extend building performance evaluation procedures beyond energy and cost criteria so as to cover aspects pertaining to user control and satisfaction.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"81 1","pages":"236 - 247"},"PeriodicalIF":1.5,"publicationDate":"2020-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88457564","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 : 2020-06-17DOI: 10.1080/14733315.2020.1777660
S. L. Paralovo, M. Spruyt, J. Lauwers, Rudi Swinnen, B. Lazarov, M. Stranger, J. Laverge
Abstract Ventilation is critical in interpreting indoor air quality (IAQ), yet most IAQ assessments do not report ventilation adequately. Most ventilation assessments use tracer gas tests (TGT) to measure total air change rate (ACH), but currently applied TGTs present three shortcomings: limited comparability between ACH and IAQ data, inadequate substances employed as tracer gases and tendency to bias arising from perfect-mixing assumption. This paper proposes a new TGT approach, employing an alternative tracer gas that is captured/analysed using commercial passive IAQ-samplers and including a careful planning-phase to account for imperfect-mixing. Two substances were selected as potential alternative tracers: 2-butoxyethyl-acetate (EGBEA) and deuterated decane (D-decane). Tracer-source tests were performed in lab, enabling enhancements to the source design. Results indicated RH influence over the emissions rates, and EGBEA’s use as tracer was discarded due to hygroscopy. Further work includes evaluating D-decane’s behaviour under varying conditions and computer-simulating TGTs to study the imperfect-mixing effects.
{"title":"Developing a new passive tracer gas test for air change rate measurement","authors":"S. L. Paralovo, M. Spruyt, J. Lauwers, Rudi Swinnen, B. Lazarov, M. Stranger, J. Laverge","doi":"10.1080/14733315.2020.1777660","DOIUrl":"https://doi.org/10.1080/14733315.2020.1777660","url":null,"abstract":"Abstract Ventilation is critical in interpreting indoor air quality (IAQ), yet most IAQ assessments do not report ventilation adequately. Most ventilation assessments use tracer gas tests (TGT) to measure total air change rate (ACH), but currently applied TGTs present three shortcomings: limited comparability between ACH and IAQ data, inadequate substances employed as tracer gases and tendency to bias arising from perfect-mixing assumption. This paper proposes a new TGT approach, employing an alternative tracer gas that is captured/analysed using commercial passive IAQ-samplers and including a careful planning-phase to account for imperfect-mixing. Two substances were selected as potential alternative tracers: 2-butoxyethyl-acetate (EGBEA) and deuterated decane (D-decane). Tracer-source tests were performed in lab, enabling enhancements to the source design. Results indicated RH influence over the emissions rates, and EGBEA’s use as tracer was discarded due to hygroscopy. Further work includes evaluating D-decane’s behaviour under varying conditions and computer-simulating TGTs to study the imperfect-mixing effects.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"26 1","pages":"276 - 286"},"PeriodicalIF":1.5,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82272397","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 : 2020-06-12DOI: 10.1080/14733315.2020.1777006
Antoine Parthoens, L. Prieels, J. Embrechts, Yves Detandt, Sébastien Pecceu, S. Gendebien, V. Lemort
Abstract The present paper describes the design improvement of a single-room ventilation unit. This ventilation system presents many advantages, however, several drawbacks exist. The first one is the acoustic disturbance. As the facilities are directly installed within the rooms, the fans’ noise may create discomfort. Furthermore, in the cold or temperate climates, condensation or frost may appear. A dedicated management should then be implemented. Finally, as the system is not centralized, communication between the different units is required to ensure the global system efficiency. A team of several industrial partners and research institutes tackles the above-mentioned issues in the frame of the “Silenthalpic” project. The project is split in three major tasks. To correctly reduce the sound emission level (i), a spectral analysis of the noise emitted by an existing unit was undertaken, revealing that frequencies under 1 kHz are mainly responsible for the noise disturbance. From this analysis, active and passive solutions for noise reduction are envisaged, showing encouraging trends. The next research aspect is the exchanger of the ventilation unit (ii). The constituting material is a new porous membrane allowing the humidity transfer (vapor or liquid). This specific exchanger is numerically modelled to predict its performances. The last considered problematic is the optimization of the ventilation and control strategies for the specific case of decentralized units (iii), taking advantage of sensors and recent communication technologies like IOT (Internet Of Things) to establish communication between decentralized units and ensure their consistent control. The association of the three aspects presented here should then lead to versatile and efficient ventilation systems.
{"title":"Multi-objective design of single room ventilation units with heat and water recovery","authors":"Antoine Parthoens, L. Prieels, J. Embrechts, Yves Detandt, Sébastien Pecceu, S. Gendebien, V. Lemort","doi":"10.1080/14733315.2020.1777006","DOIUrl":"https://doi.org/10.1080/14733315.2020.1777006","url":null,"abstract":"Abstract The present paper describes the design improvement of a single-room ventilation unit. This ventilation system presents many advantages, however, several drawbacks exist. The first one is the acoustic disturbance. As the facilities are directly installed within the rooms, the fans’ noise may create discomfort. Furthermore, in the cold or temperate climates, condensation or frost may appear. A dedicated management should then be implemented. Finally, as the system is not centralized, communication between the different units is required to ensure the global system efficiency. A team of several industrial partners and research institutes tackles the above-mentioned issues in the frame of the “Silenthalpic” project. The project is split in three major tasks. To correctly reduce the sound emission level (i), a spectral analysis of the noise emitted by an existing unit was undertaken, revealing that frequencies under 1 kHz are mainly responsible for the noise disturbance. From this analysis, active and passive solutions for noise reduction are envisaged, showing encouraging trends. The next research aspect is the exchanger of the ventilation unit (ii). The constituting material is a new porous membrane allowing the humidity transfer (vapor or liquid). This specific exchanger is numerically modelled to predict its performances. The last considered problematic is the optimization of the ventilation and control strategies for the specific case of decentralized units (iii), taking advantage of sensors and recent communication technologies like IOT (Internet Of Things) to establish communication between decentralized units and ensure their consistent control. The association of the three aspects presented here should then lead to versatile and efficient ventilation systems.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"19 1","pages":"172 - 182"},"PeriodicalIF":1.5,"publicationDate":"2020-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75505725","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 : 2020-06-12DOI: 10.1080/14733315.2020.1776519
Yanqiu Chen, Xiankun Wang, M. Yuan, Peng Wang
Abstract Vertical shafts are common structures in buildings, which accelerate smoke spread in fires due to stack effect. In this study, fire smoke movement and distribution in a ventilation shaft were studied through analysing temperature distributions, velocity distributions, CO2 concentration distributions and pressure distributions. Four exhaust rates were discussed and compared. It was found that the status of gas flow at the bottom of the shaft was firstly disturbed when the exhaust fan was working. Then some eddies appeared. As the number of eddies was increased and eddies got enlarged, gas flow in the entire shaft was influenced from the bottom to the top. A high temperature area and a strong convection area appeared close to the open door which was located at the bottom of the shaft. When the exhaust fan was working, the high temperature area and the strong convection area were both controlled at lower positions. The CO2 concentration and the pressure in the shaft were negatively related to the exhaust rate, while the neutral pressure plane height was positively related to the exhaust rate.
{"title":"Fire smoke movement and distribution in ventilation shafts","authors":"Yanqiu Chen, Xiankun Wang, M. Yuan, Peng Wang","doi":"10.1080/14733315.2020.1776519","DOIUrl":"https://doi.org/10.1080/14733315.2020.1776519","url":null,"abstract":"Abstract Vertical shafts are common structures in buildings, which accelerate smoke spread in fires due to stack effect. In this study, fire smoke movement and distribution in a ventilation shaft were studied through analysing temperature distributions, velocity distributions, CO2 concentration distributions and pressure distributions. Four exhaust rates were discussed and compared. It was found that the status of gas flow at the bottom of the shaft was firstly disturbed when the exhaust fan was working. Then some eddies appeared. As the number of eddies was increased and eddies got enlarged, gas flow in the entire shaft was influenced from the bottom to the top. A high temperature area and a strong convection area appeared close to the open door which was located at the bottom of the shaft. When the exhaust fan was working, the high temperature area and the strong convection area were both controlled at lower positions. The CO2 concentration and the pressure in the shaft were negatively related to the exhaust rate, while the neutral pressure plane height was positively related to the exhaust rate.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"213 1","pages":"118 - 134"},"PeriodicalIF":1.5,"publicationDate":"2020-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73977036","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 : 2020-05-07DOI: 10.1080/14733315.2020.1753954
Teng-Yi Wang, Kuang-Chung Tsai
Abstract Air conditioning engineers design the inlet or outlet position of a fan coil unit (FCU) system according to thermal comfort and cost. However, the effect of the position on fire growth has not been considered. In this study, the effect of the relative inlet and outlet positions was investigated. Thirty cases were simulated using fire dynamics simulator (FDS). The simulation results revealed that the air inlet and outlet positions influence the smoke movement, doorway temperature and time to flashover. The air inlet is best installed near the door because the downward flowing cold air can cool the hot smoke exiting from the door. The air outlet positioned far from the doorway efficiently enables the smoky air to move outward, while it positioned near the doorway exhausts some fresh air. Furthermore, the air outlet position has a larger influence on flashover than the air inlet position. The air outlet immediately exhausts the smoke.
{"title":"Effects of air inlet or outlet position of a fan coil unit ventilation system on smoke movement and fire severity","authors":"Teng-Yi Wang, Kuang-Chung Tsai","doi":"10.1080/14733315.2020.1753954","DOIUrl":"https://doi.org/10.1080/14733315.2020.1753954","url":null,"abstract":"Abstract Air conditioning engineers design the inlet or outlet position of a fan coil unit (FCU) system according to thermal comfort and cost. However, the effect of the position on fire growth has not been considered. In this study, the effect of the relative inlet and outlet positions was investigated. Thirty cases were simulated using fire dynamics simulator (FDS). The simulation results revealed that the air inlet and outlet positions influence the smoke movement, doorway temperature and time to flashover. The air inlet is best installed near the door because the downward flowing cold air can cool the hot smoke exiting from the door. The air outlet positioned far from the doorway efficiently enables the smoky air to move outward, while it positioned near the doorway exhausts some fresh air. Furthermore, the air outlet position has a larger influence on flashover than the air inlet position. The air outlet immediately exhausts the smoke.","PeriodicalId":55613,"journal":{"name":"International Journal of Ventilation","volume":"101 1","pages":"103 - 117"},"PeriodicalIF":1.5,"publicationDate":"2020-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77375234","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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