This project is based on measurements of the parameter relative humidity, RH (%), in two buildings: one with natural ventilation and one with mechanical ventilation. Both buildings are located in central Sweden, which...This project is based on measurements of the parameter relative humidity, RH (%), in two buildings: one with natural ventilation and one with mechanical ventilation. Both buildings are located in central Sweden, which constitutes a representative climate zone with respect to Swedish conditions. An important factor for the indoor environment, which affects human health and well-being, is the level of the relative humidity, RH (%). Research studies show that the healthiest level should be in the range of 40% - 60%. Surveys have revealed that about 70% of the employees at Swedish offices, schools and kindergartens experience that the air is too dry during the winter season. Previous studies show that the level of relative humidity in the indoor environment influences the prevalence of respiratory infections and allergies. The purpose of this study is to investigate how the relative humidity differ between the two buildings, and if this may be a cause of the health problems that users are affected by. During many years, users have complained about the environment in the building with mechanical ventilation and that they suffer from health problems. The method used in the study is air measurements of the two parameters, relative humidity and air temperature in the two buildings using data loggers. The indoor environment is affected by the outdoor climate and therefore instruments are placed outdoors to record seasonal variations. The measurements were carried out during the period October 2014 to September 2015 to include all of Sweden’s four seasons with completely different climatic conditions. The results of this study show that the relative humidity in the mechanically ventilated building is consistently significantly lower than in the building with natural ventilation whatever the time of year and temperature indoors. This study shows that mechanical ventilation in buildings affects the indoor environment negatively with respect to human health during most time of the year and this fact must be taken into consideration for the existing as well as the planning of new ventilation systems.展开更多
This paper describes several main monomial cooling methods of greenhouse in summer, including natural ventilation, mechanical ventilation, wet curtain cooling, external sun-shading etc., as well as analyzes the change...This paper describes several main monomial cooling methods of greenhouse in summer, including natural ventilation, mechanical ventilation, wet curtain cooling, external sun-shading etc., as well as analyzes the change law of the environment on temperature and humidity in greenhouse. The result shows that the four cooling methods stated above make the temperature gradients between internal and external respectively 1.1℃, 0.4℃, -2.6℃ and -1.2℃,so it is obvious that the cooling effect of wet curtain cooling is the optimum;and the internal and external humidity difference is respectively: -13%, 6%, 8% and 1%.展开更多
基金supported by funds from the National Key Research and Development Program Global Change and Mitigation Project [grant number 2017YFA0604004]the National Natural Science Foundation of China [grant numbers41675100,91737306 and U1811464]provided by the SCSIO under the project ‘Scientific investigation of the Eastern Indian Ocean in 2018’,funded by the NSFC(NORC2018-10)
文摘This project is based on measurements of the parameter relative humidity, RH (%), in two buildings: one with natural ventilation and one with mechanical ventilation. Both buildings are located in central Sweden, which constitutes a representative climate zone with respect to Swedish conditions. An important factor for the indoor environment, which affects human health and well-being, is the level of the relative humidity, RH (%). Research studies show that the healthiest level should be in the range of 40% - 60%. Surveys have revealed that about 70% of the employees at Swedish offices, schools and kindergartens experience that the air is too dry during the winter season. Previous studies show that the level of relative humidity in the indoor environment influences the prevalence of respiratory infections and allergies. The purpose of this study is to investigate how the relative humidity differ between the two buildings, and if this may be a cause of the health problems that users are affected by. During many years, users have complained about the environment in the building with mechanical ventilation and that they suffer from health problems. The method used in the study is air measurements of the two parameters, relative humidity and air temperature in the two buildings using data loggers. The indoor environment is affected by the outdoor climate and therefore instruments are placed outdoors to record seasonal variations. The measurements were carried out during the period October 2014 to September 2015 to include all of Sweden’s four seasons with completely different climatic conditions. The results of this study show that the relative humidity in the mechanically ventilated building is consistently significantly lower than in the building with natural ventilation whatever the time of year and temperature indoors. This study shows that mechanical ventilation in buildings affects the indoor environment negatively with respect to human health during most time of the year and this fact must be taken into consideration for the existing as well as the planning of new ventilation systems.
文摘This paper describes several main monomial cooling methods of greenhouse in summer, including natural ventilation, mechanical ventilation, wet curtain cooling, external sun-shading etc., as well as analyzes the change law of the environment on temperature and humidity in greenhouse. The result shows that the four cooling methods stated above make the temperature gradients between internal and external respectively 1.1℃, 0.4℃, -2.6℃ and -1.2℃,so it is obvious that the cooling effect of wet curtain cooling is the optimum;and the internal and external humidity difference is respectively: -13%, 6%, 8% and 1%.
