Uncertainties of Derived Dewpoint Temperature and Relative Humidity

Abstract This paper presents an evaluation of derived dewpoint temperature and derived relative humidity, in which the dewpoint temperature is calculated using measured ambient air temperature and measured relative humidity variables and the derived relative humidity is calculated from measured dewpoint temperature. The derived dewpoint temperature and relative humidity are calculated using algorithms provided by the World Meteorological Organization. The method of uncertainty analysis, provided by the National Institute of Standards and Technology, is applied to calculate the uncertainties of an indirect measurement of derived dewpoint temperature and derived relative humidity. The results from the uncertainty analyses of derived and observed variables suggest that the use of derived dewpoint temperature and derived relative humidity involves risk because the uncertainties of modern dewpoint temperature and relative humidity sensors can create several degrees Celsius of error in the derived dewpoint temperature and several percent in the derived relative humidity.

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The Association between Weather Conditions (Ambient Air Temperature and Relative Humidity) with Coronavirus Disease (COVID-19) Risk in Bandar Abbas, Iran

10.21203/rs.3.rs-864631/v1 ◽

2021 ◽

Author(s):

Yadolah Fakhri ◽

Mostafa Hadei ◽

Ali Rostami ◽

Ali Mouseli

Keyword(s):

Relative Humidity ◽

Air Temperature ◽

Weather Conditions ◽

Ambient Air ◽

P Value ◽

Spearman Correlation ◽

Ambient Air Temperature ◽

Spearman Correlation Test ◽

Bandar Abbas ◽

And Control

Abstract Background: This study was devoted to evaluate the association between COVID-19 infection and weather conditions in Bandar Abbas, Iran. Methods: The positive cases data was retrieved from the Ministry of Health and Medical Education of Iran (MOHME) and weather conditions from the Iran meteorological organization (IMO) from the 01, October 2020 to 27, November 2020. The components of weather consist of average of the ambient air temperature (°C) and relative humidity (%). The Spearman correlation test was used to determine the association between weather conditions (temperature and relative humidity) with COVID-19 infection.Results: Spearman analysis showed that air temperature (Coefficient = -0.303 and P-value = 0.001) were negatively associated with COVID-19 infection. However, no significant association was observed between relative humidity (Coefficient = 0.088 and P-value = 0.340) and COVID-19 infection. Hence, the ambient air temperature can be considered as a considerable variable in the COVID-19 infection in Bandar Abbas. Conclusions: The results of this study can be used for prevention and control of COVID-19 infection in areas with similar meteorological conditions in world.

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Evaluation of Abaya Design Using Thermal Manikin

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.834-836.1744 ◽

2013 ◽

Vol 834-836 ◽

pp. 1744-1748

Author(s):

Salwa Tashkandi ◽

Sinnappoo Kanesalingam ◽

Li Jing Wang

Keyword(s):

Relative Humidity ◽

Thermal Insulation ◽

Air Temperature ◽

Ambient Air ◽

Thermal Manikin ◽

Ambient Air Temperature ◽

The Mean ◽

Skin Temperatures ◽

Insulation Performance

The main objective of this research was to measure the thermal insulation using a thermal manikin dressed in various ensembles of clothing within the abaya. A range of clothing and abaya has been tested using a heated manikin. The thermal manikin experiments were conducted in dry condition. The ambient air temperature for the dry tests was set at 23oC and Relative Humidity at 50% and the mean skin temperatures averaged at 35oC. The results showed that the daily clothing and abaya affect the thermal insulation performance. It is uncomfortable to wear more layers of the daily wear clothing within the abaya. The abaya worn over the head thermally insulated slightly more than the abaya worn from the shoulder.

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An equivalent temperature drop method for evaluating the operating performances of ASHP units jointly affected by ambient air temperature and relative humidity

Energy and Buildings ◽

10.1016/j.enbuild.2020.110211 ◽

2020 ◽

Vol 224 ◽

pp. 110211

Author(s):

Yong Wu ◽

Wei Wang ◽

Yuying Sun ◽

Yiming Cui ◽

Dexing Duan ◽

...

Keyword(s):

Relative Humidity ◽

Air Temperature ◽

Temperature Drop ◽

Ambient Air ◽

Equivalent Temperature ◽

Drop Method ◽

Ambient Air Temperature

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MATHEMATICAL MODELING AND NUMERICAL SIMULATION FOR PREDICTING THE AMBIENT AIR TEMPERATURE AND RELATIVE HUMIDITY INSIDE RABBIT HOUSES

Misr Journal of Agricultural Engineering ◽

10.21608/mjae.2010.104840 ◽

2010 ◽

Vol 27 (4) ◽

pp. 1327-1342

Author(s):

M. H. Hatem ◽

K. M. Abdelbary ◽

Nagwa A. Ahmed ◽

B. A. Mohamed

Keyword(s):

Mathematical Modeling ◽

Numerical Simulation ◽

Relative Humidity ◽

Air Temperature ◽

Ambient Air ◽

Ambient Air Temperature

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THERMAL PERFORMANCE EVALUATION OF GREEN LIVING WALLS IN COMPOSITE CLIMATE

International Journal of Students Research in Technology & Management ◽

10.18510/ijsrtm.2020.842 ◽

2020 ◽

Vol 8 (4) ◽

pp. 8-16

Author(s):

Shruti Sharad Nagdeve ◽

Shweta Manchanda ◽

Anil Dewan

Keyword(s):

Relative Humidity ◽

Air Temperature ◽

Ambient Air ◽

Significant Drop ◽

Heat Gain ◽

Ambient Air Temperature ◽

High Solar Radiation ◽

The Difference ◽

Save Energy ◽

The Impact

Purpose of the study: Due to high solar radiation and extreme heat gain in composite climates, the envelope or the façade of the building becomes an essential part to modulate the heat transfer and temperature in the indoor environment. A passive sustainable approach to tackle heat gain is by adopting green living facades as the exterior skin. The objective of this research is to identify the potential of green living walls in modulating temperature and relative humidity in the composite climate of India. Methodology: This research is based on data collection in the form of a Case Study. The paper evaluates the difference of variation in temperature and relative humidity of two façade samples of the same building, one with a “green living facade” and one without it. Main Findings: The research aimed to justify that a green living facade may act as a passive strategy for composite climates. The result demonstrated that there is a significant temperature reduction between the ambient air temperature and indoor room temperature. The result also showed a notable change between ambient air temperature and the gap between the green living façade and the surface of the wall. Implications: Significant drop in indoor ambient temperature in composite climate may save energy for cooling or heating demands. Application of this study: This is a pilot study in order to carry out the main study for a similar application in order to categorize this as a passive sustainable façade strategy. Novelty/Originality of this study: The study is one of its kind attempt to investigate the impact of vertical green walls on thermal comfort in the composite climate of India.

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Seasonal Assessment of Relative Humidity, Ambient Air Temperature and CO2 Concentration Level in School Buildings of Kigali-Rwanda

International Journal of Sustainable Development & World Policy ◽

10.18488/journal.26.2019.82.83.90 ◽

2019 ◽

Vol 8 (2) ◽

pp. 83-90

Author(s):

Elisephane IRANKUNDA ◽

Dieudonne Tuyisabyimbabazi

Keyword(s):

Relative Humidity ◽

Air Temperature ◽

Concentration Level ◽

Co2 Concentration ◽

Ambient Air ◽

School Buildings ◽

Ambient Air Temperature

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Treatment of a Municipal Leachate Under Multi-Variable Conditions

Water Quality Research Journal ◽

10.2166/wqrj.1982.011 ◽

1982 ◽

Vol 17 (1) ◽

pp. 135-148

Author(s):

P.T. Wong ◽

D.S. Mavinic

Keyword(s):

Air Temperature ◽

Nutrient Loading ◽

Ambient Air ◽

Removal Rates ◽

Ambient Air Temperature

Abstract The treatability of a municipal leachate (BOD5 = 8090 mg/L) was investigated, by aerobic biostabilization, at a nutrient loading of BOD5:N:P of 100:3.2:1.1. The first stage effluents were subsequently polished by lime-magnesium coagulation. The ranges of ambient air temperature and sludge age studied were 5° to 25°C and 5 to 20 days, respectively. In the biostabilization phase, a BOD5:N:P loading of 100:3.2:1.1 was found to be “adequate” for treatment. Organic and metal removals in the first stage units were excellent. Under all conditions investigated, except for the two units close to washout conditions (5-day sludge age units at 5° and 10°C), BOD5 and COD removals of at least 99.4 and 96.4 percent, respectively, were achieved. Similarly, removal rates for most of the metals monitored were greater than 90 percent. In general, the removal of residual contaminants was not enhanced significantly by the addition of magnesium in the lime-magnesium polishing step.

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Ambient Air Temperature Assisted Crystallization for Inorganic CsPbI2Br Perovskite Solar Cells

Molecules ◽

10.3390/molecules26113398 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3398

Author(s):

Yi Long ◽

Kun Liu ◽

Yongli Zhang ◽

Wenzhe Li

Keyword(s):

Solar Cells ◽

Air Temperature ◽

High Performance ◽

Defect Density ◽

Perovskite Solar Cells ◽

Ambient Air ◽

Dark Phase ◽

High Quality ◽

Ambient Air Temperature ◽

Air Atmosphere

Inorganic cesium lead halide perovskites, as alternative light absorbers for organic–inorganic hybrid perovskite solar cells, have attracted more and more attention due to their superb thermal stability for photovoltaic applications. However, the humid air instability of CsPbI2Br perovskite solar cells (PSCs) hinders their further development. The optoelectronic properties of CsPbI2Br films are closely related to the quality of films, so preparing high-quality perovskite films is crucial for fabricating high-performance PSCs. For the first time, we demonstrate that the regulation of ambient temperature of the dry air in the glovebox is able to control the growth of CsPbI2Br crystals and further optimize the morphology of CsPbI2Br film. Through controlling the ambient air temperature assisted crystallization, high-quality CsPbI2Br films are obtained, with advantages such as larger crystalline grains, negligible crystal boundaries, absence of pinholes, lower defect density, and faster carrier mobility. Accordingly, the PSCs based on as-prepared CsPbI2Br film achieve a power conversion efficiency of 15.5% (the maximum stabilized power output of 15.02%). Moreover, the optimized CsPbI2Br films show excellent robustness against moisture and oxygen and maintain the photovoltaic dark phase after 3 h aging in an air atmosphere at room temperature and 35% relative humidity (R.H.). In comparison, the pristine films are completely converted to the yellow phase in 1.5 h.

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Evaluation of the influence of ambient air temperature and air velocity on mortar cement durability using a forced convection solar dryer

International Journal of Building Pathology and Adaptation ◽

10.1108/ijbpa-08-2020-0069 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Younes Bahammou ◽

Mounir Kouhila ◽

Haytem Moussaoui ◽

Hamza Lamsyehe ◽

Zakaria Tagnamas ◽

...

Keyword(s):

Environmental Factors ◽

Forced Convection ◽

Air Temperature ◽

Building Materials ◽

Ambient Air ◽

Physical Significance ◽

Drying Process ◽

Air Velocity ◽

Content Type ◽

Ambient Air Temperature

PurposeThis work aims to study the hydrothermal behavior of mortar cement toward certain environmental factors (ambient air temperature and air velocity) based on its drying kinetics data. The objective is to provide a better understanding and controlling the stability of mortar structures, which integrate the sorption phenomenon, drying process, air pressure and intrinsic characteristics. This leads to predict the comportment of mortar structures in relation with main environmental factors and minimize the risk of cracking mortar structures at an early age.Design/methodology/approachThermokinetic study was carried out in natural and forced convection solar drying at three temperatures 20, 30 and 40°C and three air velocities (1, 3 and 5 m.s-1). The empirical and semiempirical models tested successfully describe the drying kinetics of mortar. These models simulate the drying process of water absorbed by capillarity, which is the most common humidity transfer mechanism in building materials and contain parameters with physical significance, which integrate the effect of several environmental factors and intrinsic characteristics of mortar structures.FindingsThe models simulate the drying process of water absorbed by capillarity, which is the most common humidity transfer mechanism in building materials and contain parameters with physical significance, which integrate the effect of several environmental factors and intrinsic characteristics of mortar structures. The average activation energy obtained expressed the temperature effect on the mortar diffusivity. The drying constant and the diffusion coefficient can be used to predict the influence of these environmental factors on the drying behavior of various building materials and therefore on their durability.Originality/valueEvaluation of the effect of several environmental factors and intrinsic characteristics of mortar structures on their durability.

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