outdoor temperature
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Atmosphere ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 123
Author(s):  
Gianfranco Piccirillo ◽  
Federica Moscucci ◽  
Damiano Magrì

Little is known about the impact of air pollution on neuroautonomic system. The authors have investigated possible influence of air pollution and outdoor temperature on the carotid sinus hypersensitivity (CSH), as main cause of neurally mediated syncope in forty-years-old subjects and older. Pollutants’ concentrations and outdoor temperature of days in which 179 subjects with recurrent syncope underwent carotid sinus massage (CSM) were analyzed. Before this manoeuvre, cardiovascular control by short period heart and blood pressure spectral duration of segment between the end of P and R ECG-waves (PeR) were registred; RR variability on the same short period ECG recordings and their spectral coherence were also analyzed. CSH was found in 57 patients (28 with cardioinhibitory response and 29 subjects showed vasodepressor reaction), while 122 subjects had a normal response. CSM performed during high ozone concentrations was associated with slightly higher risk of cardioinhibitory response (odd ratio 1.012, 95% CI 1.001–1.023, p < 0.05), but neither this or other polluting agent nor outdoor temperature seemed to influence autonomic control in basal resting condition. Thus, ozone seemed to influence response to the CSM in CSH patients and it is probably able to facilitate a cardioinhibitory response, perhaps through an increase of nerve acetylcholine release. P→PR coherence could be useful in predicting a sinus cardioinhibitory hypersensitivity in those cases when CSM is contraindicated.


Atmosphere ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 28
Author(s):  
Yun Hu ◽  
Yihui Wu ◽  
Qun Wang ◽  
Jian Hang ◽  
Qingman Li ◽  
...  

Mechanical ventilation consumes a huge amount of global energy. Natural ventilation is a crucial solution for reducing energy consumption and enhancing the capacity of atmospheric self-purification. This paper evaluates the impacts of indoor-outdoor temperature differences on building ventilation and indoor-outdoor air pollutant dispersion in urban areas. The Computational Fluid Dynamics (CFD) method is employed to simulate the flow fields in the street canyon and indoor environment. Ventilation conditions of single-side ventilation mode and cross-ventilation mode are investigated. Air change rate, normalized concentration of traffic-related air pollutant (CO), intake fraction and exposure concentration are calculated to for ventilation efficiency investigation and exposure assessment. The results show that cross ventilation increases the air change rate for residential buildings under isothermal conditions. With the indoor-outdoor temperature difference, heating could increase the air change rate of the single-side ventilation mode but restrain the capability of the cross-ventilation mode in part of the floors. Heavier polluted areas appear in the upstream areas of single-side ventilation modes, and the pollutant can diffuse to middle-upper floors in cross-ventilation modes. Cross ventilation mitigates the environmental health stress for the indoor environment when indoor-outdoor temperature difference exits and the personal intake fraction is decreased by about 66% compared to the single-side ventilation. Moreover, the existence of indoor-outdoor temperature differences can clearly decrease the risk of indoor personal exposure under both two natural ventilation modes. The study numerically investigates the building ventilation and pollutant dispersion in the urban community with natural ventilation. The method and the results are helpful references for optimizing the building ventilation plan and improving indoor air quality.


Author(s):  
V. D. Petrash ◽  
V. O. Makarov ◽  
A. A. Khomenko

The results of the analytical study substantiated the operating conditions for the highly efficient use of the temperature potential of seawater in heat pump heating systems (HPHS) for buildings a building with correspondingly improved environmental indicators. Based on the analysis of the regional conditions of the Odessa water area of the Black Sea, the initial parameters have been substantiated and rational modes of operation of an improved HPHS with central, decentralized or local heating of the subscriber energy carrier have been determined. As indicators for evaluating the efficiency of the HPHS operation, the conversion factor of energy flows and the specific consumption of external energy for the drive of the compressor and the circulating pump of cooled water in the operation of heat pump units were considered. For seawater in the Odessa water area of the Black Sea during the entire heating period, the following temperatures were considered as initial data for analysis: water at the inlet to the evaporator (5–10) ° C, at the outlet (1 °C); calculated temperature difference of the coolant in the heating system (50–40) °C, indoor air (20 °C); estimated outdoor temperature (–18 °C). The characteristic correspondence between the flow rates of the cooled sea water and the heated energy carrier of the heat supply system was taken into account. The prerequisites of high efficiency of the heat pump heat supply system in which the actual conversion coefficient exceeds the seasonal normalized calculated and minimum value at an outdoor temperature of (–10) °C under the limiting conditions of the monoenergy regime for both new and reconstructed buildings were substantiated. In the course of the study, it has been determined that the total specific consumption of external energy for the compressor drive and the circulation of cooled water in the operation of a heat pump unit with a characteristic ratio of water equivalents, even under the limiting conditions of the monoenergetic mode of operation of the heat supply system at an outdoor temperature of (–10) °C, are within the range of generally accepted values (w = 0.28–0.34).


2021 ◽  
Vol 2069 (1) ◽  
pp. 012073
Author(s):  
E B Møller ◽  
J Helgason

Abstract To make a hygrothermal assessment of a building construction, e.g. wall or roof, weather files as well as information on indoor moisture load are needed, however only to some extent available for Greenlandic conditions. This paper describes a project that had a twofold aim: 1) create weather files for four different cities in Greenland in a simple way, 2) determine the typical moisture load in a Greenlandic dwelling to see if the international standard ISO 13788 is applicable in Greenland when describing indoor moisture load. The four chosen cities are placed at the west coast of Greenland. Hourly weather data of 10 years for the four cities were obtained from the meteorological institutes of Denmark and Greenland, from this a reference year with hourly values was created for each city. The paper also describes how incomplete data was treated. Five dwellings were chosen in each city to assess the indoor moisture load. Temperature and relative humidity were measured hourly in living rooms of these dwellings. Furthermore, outdoor temperature and relative humidity were measured in the four cities. The moisture load in the dwellings were scattered in humidity class 1-4, similar to what has been measured in Danish dwellings, consequently ISO 13788 may be applicable in Greenland.


2021 ◽  
Vol 2069 (1) ◽  
pp. 012168
Author(s):  
Zihan Xie ◽  
Chang Shu ◽  
Ben Zegen Reich ◽  
Lin Wang ◽  
Daniel Baril ◽  
...  

Abstract Due to global climate change, the world has been experiencing significant increases in average temperatures and the frequency and intensity of extreme weather events such as heatwaves. The overheating problem in indoor spaces of buildings has become a concern to the comfort and health of building occupants, especially vulnerable populations such as the elderly, children, or the sick. A field monitoring network consisting of rooftop weather stations and indoor sensors has been set up on 11 buildings of different types in Montreal, Canada. This paper presents the results of field measurements of indoor thermal conditions of six school buildings to assess the risks of summertime overheating. These six primary school buildings were built in 1930-1966 with window-wall-ratios between 10-30% and limited mechanical ventilation. The indoor dry-bulb air temperature, relative humidity, and CO2 concentrations are measured by indoor wireless sensors. The weather conditions, including dry-bulb temperature, relative humidity, solar radiation, rainfall, wind speed, and wind direction, are measured by rooftop weather stations. Measurements presented in this paper are collected from July to September 2020, which include four different time intervals: (a) during two heatwaves, (b) during summer break when schools were closed, and (c) when schools were reopened, and windows were intermittently opened. Data analysis shows that the indoor and outdoor temperature difference has a strong linear correlation with the outdoor temperature observed for all school buildings. This correlation is also affected by building operations, such as opening windows, closing blinds, and the micro-climate of their surroundings.


Author(s):  
P.I. Kalandarov ◽  

The article deals with the problems of improving the production of fodder and the development of a new method of hydroponic green feed. The use of automation elements using humidity and temperature sensors to regulate the irrigation process, measuring soil moisture, outdoor temperature, as well as additional luminosity is shown. The possibility of using abundant devices to control the technological process is shown. A program has been developed. Amma for control of the technological process of growing green feed, in the programming language for controllers, describes proportionally integral- differential law of regulation to ensure high accuracy of temperature maintenance, giving the method of setting PID coefficients.


Author(s):  
Sensus Wijonarko ◽  
Mahmudi ◽  
Tatik Maftukhah ◽  
Dadang Rustandi ◽  
Purwowibowo ◽  
...  

Author(s):  
V.K. Evsyukova

The article discusses the practical significance of using the infrared scanning method to optimize the microclimate of wintering grounds for bee colonies in extreme conditions of the cryolithozone. When monitoring the microclimate by generally accepted zoohygienic methods, the devices record specific indicators of a particular parameter (temperature, humidity, air velocity, pressure, noise, light), while the reason for the deviation from the standard indicators for optimizing the microclimate is not always possible to find out. When using the infrared scanning method with the Irtis 2000SN thermal imager to determine the reasons for the deviation of the microclimate parameters from the standards, the following results were obtained: defects of enclosing structures were found: joints of walls and floor and joints of floor boards with a minus temperature of up to -21°C; the entrance group with a defect of heat leakage, warming the outdoor air to -36°C at an outdoor temperature of -48°C; the reason for the deviation of the air velocity of 0.18 m/s deviation from the standard by 0.08 m/s are defects of enclosing structures (Fig.7,8,12). The targeted elimination of the defects of the enclosing structures detected by infrared scanning made it possible to quickly optimize the parameters of the microclimate of the winter garden, thereby increasing the results of successful wintering of bee colonies. The analysis of the wintering results showed that the proportion of successful wintering in 2019 was 90%, which is 20% more than in 2018 and 30% more than in 2017


2021 ◽  
Vol 13 (19) ◽  
pp. 10638
Author(s):  
Girish Rentala ◽  
Yimin Zhu ◽  
Neil M. Johannsen

Recent studies have established immersive virtual environments (IVEs) as promising tools for studying human thermal states and human–building interactions. One advantage of using immersive virtual environments is that experiments or data collection can be conducted at any time of the year. However, previous studies have confirmed the potential impact of outdoor temperature variations, such as seasonal variations on human thermal sensation. To the best of our knowledge, no study has looked into the potential impact of variations in outdoor temperatures on experiments using IVE. Thus, this study aimed to determine if different outdoor temperature conditions affected the thermal states in experiments using IVEs. Experiments were conducted using a head mounted display (HMD) in a climate chamber, and the data was analyzed under three temperature ranges. A total of seventy-two people participated in the experiments conducted in two contrasting outdoor temperature conditions, i.e., cold and warm outdoor conditions. The in situ experiments conducted in two cases, i.e., cooling in warm outdoor conditions and heating in cold outdoor conditions, were used as a baseline. The baseline in-situ experiments were then compared with the IVE experiments conducted in four cases, i.e., cooling in warm and cold outdoor conditions and heating in warm and cold outdoor conditions. The selection of cooling in cold outdoor conditions and heating in warm outdoor conditions for IVE experiments is particularly for studying the impact of outdoor temperature variations. Results showed that under the experimental and outdoor temperature conditions, outdoor temperature variations in most cases did not impact the results of IVE experiments, i.e., IVE experiments can replicate a temperature environment for participants compared to the ones in the in situ experiments. In addition, the participant’s thermal sensation vote was found to be a reliable indicator between IVE and in situ settings in all studied conditions. A few significantly different cases were related to thermal comfort, thermal acceptability, and overall skin temperature.


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