The outbreak of COVID-19 and the spread of infectious pathogens through bioaerosols have once again aroused widespread concern worldwide.Isolation ward is an important place to prevent the spread of infectious bioaero...The outbreak of COVID-19 and the spread of infectious pathogens through bioaerosols have once again aroused widespread concern worldwide.Isolation ward is an important place to prevent the spread of infectious bioaerosols.However,infection of health care workers(HCWs)in the isolation ward often occurs,so it is ur-gent to carry out relevant research to reduce the cross-infection between HCWs and patients.In this paper,the temporal and spatial distribution characteristics of bioaerosols under three mixed ventilation modes in a single ward were studied,namely,upper supply side return air of Case 1 and side supply and side return ventilation are Case 2 and Case 3 respectively.The results show that the removal efficiency of bioaerosol in the ventilation mode of Case 3,in which directional airflow is formed from the air supply inlet to the release source and then to the exhaust outlet,is 46.6%and 67.7%higher than that of Case 1 and Case 2,respectively.In addition,ventilation methods based on mixed theory do not guarantee good air quality in the breathing zone(1.3 m to 1.7 m)of HCWs,which may increase the inhalation risk for HCWs.It is hoped that our results can provide some useful suggestions for optimizing the airflow layout of the isolation ward,reducing the risk of cross-infection,and virus elimination.展开更多
There are prototypes of social housing massively built in contrasting climatic conditions,generating thermal comfort needs that are difficult to satisfy by the users themselves.Variation of indoor air volume in living...There are prototypes of social housing massively built in contrasting climatic conditions,generating thermal comfort needs that are difficult to satisfy by the users themselves.Variation of indoor air volume in living spaces where the use of air conditioning and natural ventilation strategies provides elements to improve thermal comfort conditions.This research shows the thermal performance located in a representative social housing according to Mexico’s National Housing Commission.Operative temperature results from a benchmark case were compared to six Virtual Evaluation Models,using the Dynamic Thermal Simulation tool Design Builder®from the perspective of probability.The main objective was to determine the minimum use of active systems with different indoor air volumes and improve comfort conditions to promote sustainable living in social housing.The analysis was conducted under an adaptive comfort range according to three different climate conditions in Mexico adopting a Numerical Theoretical Method.The main findings can be divided into two parts:a)the impact of the indoor air volume on thermal performance was evidenced in a proportion of time in three representative climates of the central region of Mexico,and b)no relationship was found between indoor air volume and thermal comfort in sub-humid cold climate;in sub-humid temperate climate,the same number of comfort hours was found in two different models,and in sub-humid warm climate,an inversely proportional relationship was found between indoor air volume and the comfort hours.This findings implies a greater knowledge relative to what we know about sub-humid cold,temperate and warm climates.展开更多
At present,laminar airflow(LAF)systems and mixing ventilation(MV)systems are two commonly used ventila-tion solutions for operating rooms(ORs)to ensure the required indoor air quality.However,recent studies have shown...At present,laminar airflow(LAF)systems and mixing ventilation(MV)systems are two commonly used ventila-tion solutions for operating rooms(ORs)to ensure the required indoor air quality.However,recent studies have shown that there is little difference in the prevalence of surgical site infection(SSI)for the LAF systems and MV systems.The objective of this study was to compare the performance of an LAF system with an MV system in ORs at St.Olavs hospital,Norway.In this study,all the experimental measurements were conducted in real ORs with LAF and MV systems.This study found that the air velocity above the surgical incision is approximately two times higher in the OR with LAF than that in the OR with MV.The use of surgical lamps and different airflow patterns may contribute to the different surgical microenvironment of ORs with LAF and MV.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.42122058 and 41977368)the National Key R&D Program of China(2021YFF0604000)Natural Science Foundation of Hebei Province(No.E2021502046,and Fundamental Research Funds for the Central Universities(Nos.2021MS075 and 2020YJ007).
文摘The outbreak of COVID-19 and the spread of infectious pathogens through bioaerosols have once again aroused widespread concern worldwide.Isolation ward is an important place to prevent the spread of infectious bioaerosols.However,infection of health care workers(HCWs)in the isolation ward often occurs,so it is ur-gent to carry out relevant research to reduce the cross-infection between HCWs and patients.In this paper,the temporal and spatial distribution characteristics of bioaerosols under three mixed ventilation modes in a single ward were studied,namely,upper supply side return air of Case 1 and side supply and side return ventilation are Case 2 and Case 3 respectively.The results show that the removal efficiency of bioaerosol in the ventilation mode of Case 3,in which directional airflow is formed from the air supply inlet to the release source and then to the exhaust outlet,is 46.6%and 67.7%higher than that of Case 1 and Case 2,respectively.In addition,ventilation methods based on mixed theory do not guarantee good air quality in the breathing zone(1.3 m to 1.7 m)of HCWs,which may increase the inhalation risk for HCWs.It is hoped that our results can provide some useful suggestions for optimizing the airflow layout of the isolation ward,reducing the risk of cross-infection,and virus elimination.
基金This paper was made supported by grants from Mexico’s National Council of Science and Technology(CONACyT,by its Spanish acronym).
文摘There are prototypes of social housing massively built in contrasting climatic conditions,generating thermal comfort needs that are difficult to satisfy by the users themselves.Variation of indoor air volume in living spaces where the use of air conditioning and natural ventilation strategies provides elements to improve thermal comfort conditions.This research shows the thermal performance located in a representative social housing according to Mexico’s National Housing Commission.Operative temperature results from a benchmark case were compared to six Virtual Evaluation Models,using the Dynamic Thermal Simulation tool Design Builder®from the perspective of probability.The main objective was to determine the minimum use of active systems with different indoor air volumes and improve comfort conditions to promote sustainable living in social housing.The analysis was conducted under an adaptive comfort range according to three different climate conditions in Mexico adopting a Numerical Theoretical Method.The main findings can be divided into two parts:a)the impact of the indoor air volume on thermal performance was evidenced in a proportion of time in three representative climates of the central region of Mexico,and b)no relationship was found between indoor air volume and thermal comfort in sub-humid cold climate;in sub-humid temperate climate,the same number of comfort hours was found in two different models,and in sub-humid warm climate,an inversely proportional relationship was found between indoor air volume and the comfort hours.This findings implies a greater knowledge relative to what we know about sub-humid cold,temperate and warm climates.
文摘At present,laminar airflow(LAF)systems and mixing ventilation(MV)systems are two commonly used ventila-tion solutions for operating rooms(ORs)to ensure the required indoor air quality.However,recent studies have shown that there is little difference in the prevalence of surgical site infection(SSI)for the LAF systems and MV systems.The objective of this study was to compare the performance of an LAF system with an MV system in ORs at St.Olavs hospital,Norway.In this study,all the experimental measurements were conducted in real ORs with LAF and MV systems.This study found that the air velocity above the surgical incision is approximately two times higher in the OR with LAF than that in the OR with MV.The use of surgical lamps and different airflow patterns may contribute to the different surgical microenvironment of ORs with LAF and MV.
