Thermal Characteristics Comparison for Several Roofs of Naturally Ventilated Rooms

2012 ◽  
Vol 170-173 ◽  
pp. 2681-2685
Author(s):  
Shu Kui Zheng ◽  
Jie Zhang
Keyword(s):  
Heat Flux ◽  
Air Temperature ◽  
Concrete Slab ◽  
Thermal Characteristics ◽  
Climatic Conditions ◽  
Outdoor Air ◽  
Strong Negative Correlation ◽  
Inner Surface ◽  
Insulation Performance ◽  
Light Green

Four kinds of insulation roofs of naturally ventilated rooms in Chengdu(P.R.C) were tested to evaluate the thermal performance in summer. The thermal characteristics of roofs with different construction were compared by regression analysis. The experimental results showed a strong negative correlation between the highest outdoor air temperature and the largest temperature increment. As the highest outdoor air over 29.1°C, the light green ventilated roof has the best insulation performance. Under "sunny - rain" climatic conditions in summer, the heat flux through the extruded polystyrene insulation roof was always toward outside, which is not good for cooling the structural roof at night. The heat flux of inner surface of concrete slab ventilated roof was the most sensitive with mean solar radiation, and it has the worst performance for attenuating fluctuations of solar air temperature of outdoors.

scholarly journals Modelling relationships between raw milk quality parameters and climatic conditions - the case study of a 3-years survey in Serbia

2020 ◽  
Vol 9 (2) ◽  
pp. 295-306
Author(s):  
Ilija Djekic ◽  
Jelena Miočionović ◽  
Marija Bojčevski ◽  
Nada Šmigić ◽  
Igor Tomašević
Keyword(s):  
Air Temperature ◽  
Agricultural Practices ◽  
Titratable Acidity ◽  
Raw Milk ◽  
Quality Parameters ◽  
Quality Characteristics ◽  
Climatic Conditions ◽  
Plate Count ◽  
Outdoor Air

This work examined the relationships between quality characteristics of raw milk and climatic conditions. Over a period of three years, a total of 5,065 samples were collected encompassing two types of farms. The quality characteristics analysed were titratable acidity (TA), total plate count (TPC) and somatic cells count (SCC). Climatic conditions were evaluated in respect to the outdoor air temperature, pressure, humidity and precipitation. Big farms showed a stronger correlation between TA and climatic conditions as opposed to SCC and climatic conditions. TPC was out of limit in big farms when the outdoor air temperature was higher than 19.8 °C (p<0.05) and during periods with accumulated precipitation over 4.2 mm (p>0.05). Small farms showed a stronger correlation between SCC and climatic conditions as opposed to TA. In these farms, occurrence of acidity out of limit was detected in less than 7.2% of samples. Samples with TA out of limit were observed when air temperature was higher than 18.4 °C (p<0.05) and accumulated precipitation was below 3.1 mm (p>0.05). These results can be used to improve good agricultural practices in respect to climatic conditions and size of farms.

scholarly journals Bin Weather Data for HVAC Systems Energy Calculations

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3501
Author(s):  
Konstantinos T. Papakostas ◽  
Dimitrios Kyrou ◽  
Kyrillos Kourous ◽  
Dimitra Founda ◽  
Georgios Martinopoulos
Keyword(s):  
Air Temperature ◽  
Air Conditioning ◽  
Energy Performance ◽  
Climatic Conditions ◽  
Weather Data ◽  
Climatic Data ◽  
Outdoor Air ◽  
Energy Demands ◽  
Hourly Temperature

The increase in global air temperature is well documented, as during the last several years each decade has been consecutively warmer than the preceding. As climatic conditions affect the energy performance of buildings, the changes in outdoor air temperature and humidity will inevitably lead to significant alterations in energy consumption and costs for the heating, ventilating and air conditioning (HVAC) of buildings. The availability and quality of climatic data play an important role in the accuracy of energy analysis results. In this study, the hourly temperature and relative humidity of outdoor air measurements, for a period of three decades (1983–2012), recorded at the climatic station of the National Observatory of Athens were processed, and an up-to-date set of specific data for the application of bin methods was produced and presented. The data were then used to calculate changes in the energy demands in a typical office building throughout the specified period. Results showed a progressive reduction in the low and increase in the high temperature intervals, leading to an increase in the building’s annual energy requirements for air conditioning of up to 14.5% from the first to the third decade, with decrease in the energy demands for heating and increase in the energy demands for cooling.

scholarly journals Analysis of temperature gradient in concrete pavement

2018 ◽  
Vol 67 (4) ◽  
pp. 59-70
Author(s):  
Grzegorz Rogojsz
Keyword(s):  
Thermal Stress ◽  
Temperature Distribution ◽  
Temperature Gradient ◽  
Air Temperature ◽  
Experimental Research ◽  
Analytical Methods ◽  
Concrete Slab ◽  
Climatic Conditions ◽  
Concrete Pavement

The paper presents the results of experimental research that is the continuation of the research conducted as a part of a Ph.D. dissertation. The experimental research consisted in measuring the temperature at various depths inside a concrete slab, including its surface, and measuring the air temperature. The temperature distribution was measured on a concrete slab with dimensions similar to real road slab dimensions. The aim of the research was to determine the temperature gradient in the concrete slab in Polish climatic conditions and to verify the available analytical methods. Keywords: temperature gradient, concrete pavement, thermal stress in concrete pavement.

scholarly journals Assessment of the possibility of profiting from solar energy through the use of walls with external sheet metal cladding

2018 ◽  
Vol 45 ◽  
pp. 00105
Author(s):  
Henryk Żelazny
Keyword(s):  
Heat Transfer ◽  
Air Temperature ◽  
The Sun ◽  
Outdoor Air ◽  
The West ◽  
Metal Cladding ◽  
Inner Surface ◽  
Western Side ◽  
Livestock Building ◽  
Similar Assessment

The possibility of profiting from solar radiation through external walls was studied for an experimental, windowless livestock building. Temperature measurements on the wall surfaces were taken during winter, in two measuring series. On the first day, the average sol-air temperature on the outer surface of the east-facing wall was 7.4 °C and was even up to 2.2 °C lower than temperature of the outdoor air which was 9.6 °C. With the averaged temperature of inner surface of the wall reaching 21.3 °C, heat transfer form the outside into the building was impossible. An identical tendency in temperature distribution on surfaces was noticed on the west-facing wall. In the second measuring cycle, the sun temperature on external wall surfaces increased significantly — 13.3 °C on the eastern side, and 14.1 °C on the western side. They were noticeably higher than the outdoor air temperature which was 9.1 °C. However, the high indoor surface temperatures on the eastern and western walls — 21.2 °C and 21.0 °C respectively, proved that in this case too, the transfer of heat generated by the sun’s radiation into the building was impossible. The tests results imply that we should exclude reheating the building with the heat from sun heat external walls during winter. However, a similar assessment including more measuring series and several objects, could be also be performed during interim seasons.

Evaluation of Thermal Comfort for Workers at the Construction Site in a Block-Modular Building Made of Sandwich Panels

2019 ◽  
pp. 60-65
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Experimental Studies ◽  
Sandwich Panels ◽  
Thermal Characteristics ◽  
Internal Surface ◽  
Thermal Conditions ◽  
Climatic Conditions ◽  
Winter Period ◽  
Construction Site

The purpose of this work is to assess the thermal comfort of a block-modular building on the construction site. The experimental studies for determining the thermal conditions of the cabins in the winter and the summer time of the city of Zhengzhou was carried out at different locations of the modular house made of sandwich panels for determining the category of living comfort. The variations of air temperature and relative humidity in the cabin were analyzed. The difference between outdoor and indoor air temperatures, as well as the changes in air temperature and heat flux on the internal surface of the different walls of the building by their location relative to the cardinal directions were considered. Reasons for decreasing the comfort in the room and the attenuation of the experimental amplitude of the outdoor temperature fluctuations in the enclosing structure as well as the thermal properties of enclosing structures of the block-modular building under different climatic conditions were studied. It is shown that it is necessary to take into account the reflection of heat inside the premises and their ventilation when designing enclosing structures of mobile buildings. It is revealed that in the winter period for energy saving it is necessary to increase in addition thermal characteristics of the western wall of domestic buildings.

scholarly journals Response of the Energy Balance on the Margin of the Greenland Ice Sheet to Temperature Changes

1990 ◽  
Vol 36 (123) ◽  
pp. 217-221 ◽  
Author(s):  
Roger J. Braithwaite ◽  
Ole B. Olesen
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Air Temperature ◽  
Sensible Heat Flux ◽  
Ice Sheet ◽  
Temperature Response ◽  
Greenland Ice Sheet ◽  
Energy Balance Model ◽  
Balance Model ◽  
Sensible Heat

AbstractDaily ice ablation on two outlet glaciers from the Greenland ice sheet, Nordbogletscher (1979–83) and Qamanârssûp sermia (1980–86), is related to air temperature by a linear regression equation. Analysis of this ablation-temperature equation with the help of a simple energy-balance model shows that sensible-heat flux has the greatest temperature response and accounts for about one-half of the temperature response of ablation. Net radiation accounts for about one-quarter of the temperature response of ablation, and latent-heat flux and errors account for the remainder. The temperature response of sensible-heat flux at QQamanârssûp sermia is greater than at Nordbogletscher mainly due to higher average wind speeds. The association of high winds with high temperatures during Föhn events further increases sensible-heat flux. The energy-balance model shows that ablation from a snow surface is only about half that from an ice surface at the same air temperature.

scholarly journals Seasonal Climate Impacts on Vocal Activity in Two Neotropical Nonpasserines

Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 319
Author(s):  
Cristian Pérez-Granados ◽  
Karl-L. Schuchmann
Keyword(s):  
Air Temperature ◽  
Daily Rainfall ◽  
Climatic Conditions ◽  
Dry Season ◽  
Climate Impacts ◽  
Calling Behavior ◽  
Wet Season ◽  
Focal Species ◽  
Calling Activity ◽  
Vocal Activity

Climatic conditions represent one of the main constraints that influence avian calling behavior. Here, we monitored the daily calling activity of the Undulated Tinamou (Crypturellus undulatus) and the Chaco Chachalaca (Ortalis canicollis) during the dry and wet seasons in the Brazilian Pantanal. We aimed to assess the effects of climate predictors on the vocal activity of these focal species and evaluate whether these effects may vary among seasons. Air temperature was positively associated with the daily calling activity of both species during the dry season. However, the vocal activity of both species was unrelated to air temperature during the wet season, when higher temperatures occur. Daily rainfall was positively related to the daily calling activity of both species during the dry season, when rainfall events are scarce and seem to act as a trigger for breeding phenology of the focal species. Nonetheless, air temperature was negatively associated with the daily calling activity of the Undulated Tinamou during the wet season, when rainfall was abundant. This study improves our understanding of the vocal behavior of tropical birds and their relationships with climate, but further research is needed to elucidate the mechanisms behind the associations found in our study.

Modeling soil temperature using air temperature features in diverse climatic conditions with complementary machine learning models

2021 ◽  
Vol 185 ◽  
pp. 106158
Author(s):  
Maryam Bayatvarkeshi ◽  
Suraj Kumar Bhagat ◽  
Kourosh Mohammadi ◽  
Ozgur Kisi ◽  
M. Farahani ◽  
...  
Keyword(s):  
Machine Learning ◽  
Soil Temperature ◽  
Air Temperature ◽  
Climatic Conditions ◽  
Learning Models ◽  
Machine Learning Models

scholarly journals Changes in Air Temperature and Snow Cover in Winter in Poland

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 68
Author(s):  
Arkadiusz M. Tomczyk ◽  
Ewa Bednorz ◽  
Katarzyna Szyga-Pluta
Keyword(s):  
Snow Cover ◽  
Air Temperature ◽  
Winter Season ◽  
Primary Objective ◽  
Climatic Conditions ◽  
Cover Depth ◽  
North Eastern ◽  
Northern Regions ◽  
Maximum Air Temperature ◽  
Snow Cover Depth

The primary objective of the paper was to characterize the climatic conditions in the winter season in Poland in the years 1966/67–2019/20. The study was based on daily values of minimum (Tmin) and maximum air temperature (Tmax), and daily values of snow cover depth. The study showed an increase in both Tmin and Tmax in winter. The most intensive changes were recorded in north-eastern and northern regions. The coldest winters were recorded in the first half of the analyzed multiannual period, exceptionally cold being winters 1969/70 and 1984/85. The warmest winters occurred in the second half of the analyzed period and among seasons with the highest mean Tmax, particularly winters 2019/20 and 1989/90 stood out. In the study period, a decrease in snow cover depth statistically significant in the majority of stations in Poland was determined, as well as its variability both within the winter season and multiannual.

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