Infectious disease departments in hospitals require pressure gradient to create unidirectional airflow to prevent the spread of contaminants,typically by creating active air infiltration through the difference between...Infectious disease departments in hospitals require pressure gradient to create unidirectional airflow to prevent the spread of contaminants,typically by creating active air infiltration through the difference between supply and exhaust air volumes.The door gap is the channel of air flow between rooms,so its height has an important influence on the pressure difference and infiltration air volume of the room.There is still a lack of research on setting reasonable ventilation strategies according to the different heights of door gaps at different positions in the building.In this study,model of a set of isolation wards was established and analyzed using the multi-zone simulation software CONTAM,and the ventilation strategies with different heights of door gaps were applied to the actual infection diseases department.The results show that in a building with ventilation system divided by functional area,the difference in the height of the door gaps requires different active infiltration air volumes.Pressure fluctuations in the medical and patient corridors are greater than in other rooms.The significance of this study is to understand the active infiltration of air to guide the design and operation of ventilation systems in infectious disease hospitals or building remodeled to isolate close contacts of COVID-19 patients.It is also instructive for the design of pressure gradients in clean workshops,biological laboratories,and other similar buildings.展开更多
In the residential sector,biomass appliances are widely used for space heating and often combined with other systems.This work aims at comparing the final and primary energy consumption of different configurations,inc...In the residential sector,biomass appliances are widely used for space heating and often combined with other systems.This work aims at comparing the final and primary energy consumption of different configurations,including a conventional and a ducted pellet stove and a wood log stove using air as heat transfer fluid.A dynamic analysis of the interaction between biomass stoves and conventional heating systems,such as gas boilers and radiators,is carried out within a typical single-family house in a mild climate,using TRNSYS software.In addition,natural ventilation of the building is considered using CONTAM,with a focus on external infiltrations and internal air circulation due to the buoyancy effect.Results show that the biomass device in one room promotes the airflows between adjacent thermal zones,enhancing the heat distribution through door openings,in particular when an air ducted stove is present.The final energy consumption resulting from simulations with wood-burning stoves is 21%higher than pellet stoves.The pellet stove results in similar final energy and a 30%increase in overall primary energy,while the wood stove increases the final energy by 22%and approximately 40%of overall primary energy compared to the case of a traditional gas system coupled to radiators which is considered as reference.Nevertheless,non-renewable primary energy savings are higher than 50%with pellet stoves and 60%with wood-log stoves.展开更多
Indoor air dynamics and quality in high density residential buildings can be complex as it is affected by both building parameters,pollution sources,and outdoor meteorological conditions.The present study used CONTAM ...Indoor air dynamics and quality in high density residential buildings can be complex as it is affected by both building parameters,pollution sources,and outdoor meteorological conditions.The present study used CONTAM simulations to investigate the intra-building transport and concentration of an inert pollutant continuously emitted from an underground garage of a 15-floor building under moderate Mediterranean weather.The effects of outdoor meteorological conditions(air temperature,wind speed and direction)on indoor distribution of the emitted pollutant was tested under constant conditions.The importance of using actual transient meteorological data and the impact of their temporal resolution on calculated concentrations and exposure levels were also investigated.Vertical profiles of air exchange rate(AER)and CO concentration were shown to be sensitive to indoor-outdoor temperature difference,which controls the extent of the stack effect and its importance relative to wind effect.Even under constant conditions,transient mode simulations revealed that the time needed for pollutant distribution to reach steady state can be quite long(>24h in some cases).The temporal resolution(Ih vs.8h)of the meteorological data input was also found to impact calculated exposure levels,in an extent that varied with time,meteorological conditions and apartment position.展开更多
文摘Infectious disease departments in hospitals require pressure gradient to create unidirectional airflow to prevent the spread of contaminants,typically by creating active air infiltration through the difference between supply and exhaust air volumes.The door gap is the channel of air flow between rooms,so its height has an important influence on the pressure difference and infiltration air volume of the room.There is still a lack of research on setting reasonable ventilation strategies according to the different heights of door gaps at different positions in the building.In this study,model of a set of isolation wards was established and analyzed using the multi-zone simulation software CONTAM,and the ventilation strategies with different heights of door gaps were applied to the actual infection diseases department.The results show that in a building with ventilation system divided by functional area,the difference in the height of the door gaps requires different active infiltration air volumes.Pressure fluctuations in the medical and patient corridors are greater than in other rooms.The significance of this study is to understand the active infiltration of air to guide the design and operation of ventilation systems in infectious disease hospitals or building remodeled to isolate close contacts of COVID-19 patients.It is also instructive for the design of pressure gradients in clean workshops,biological laboratories,and other similar buildings.
基金This study was developed from the Action D3 of the LIFE+PREPAIR Project(https://www.lifeprepair.eu/)which received funding from LIFE Program,under Grant Agreement LIFE 15 IPE IT013.
文摘In the residential sector,biomass appliances are widely used for space heating and often combined with other systems.This work aims at comparing the final and primary energy consumption of different configurations,including a conventional and a ducted pellet stove and a wood log stove using air as heat transfer fluid.A dynamic analysis of the interaction between biomass stoves and conventional heating systems,such as gas boilers and radiators,is carried out within a typical single-family house in a mild climate,using TRNSYS software.In addition,natural ventilation of the building is considered using CONTAM,with a focus on external infiltrations and internal air circulation due to the buoyancy effect.Results show that the biomass device in one room promotes the airflows between adjacent thermal zones,enhancing the heat distribution through door openings,in particular when an air ducted stove is present.The final energy consumption resulting from simulations with wood-burning stoves is 21%higher than pellet stoves.The pellet stove results in similar final energy and a 30%increase in overall primary energy,while the wood stove increases the final energy by 22%and approximately 40%of overall primary energy compared to the case of a traditional gas system coupled to radiators which is considered as reference.Nevertheless,non-renewable primary energy savings are higher than 50%with pellet stoves and 60%with wood-log stoves.
文摘Indoor air dynamics and quality in high density residential buildings can be complex as it is affected by both building parameters,pollution sources,and outdoor meteorological conditions.The present study used CONTAM simulations to investigate the intra-building transport and concentration of an inert pollutant continuously emitted from an underground garage of a 15-floor building under moderate Mediterranean weather.The effects of outdoor meteorological conditions(air temperature,wind speed and direction)on indoor distribution of the emitted pollutant was tested under constant conditions.The importance of using actual transient meteorological data and the impact of their temporal resolution on calculated concentrations and exposure levels were also investigated.Vertical profiles of air exchange rate(AER)and CO concentration were shown to be sensitive to indoor-outdoor temperature difference,which controls the extent of the stack effect and its importance relative to wind effect.Even under constant conditions,transient mode simulations revealed that the time needed for pollutant distribution to reach steady state can be quite long(>24h in some cases).The temporal resolution(Ih vs.8h)of the meteorological data input was also found to impact calculated exposure levels,in an extent that varied with time,meteorological conditions and apartment position.
