Numerical simulation of thermal mass enhanced envelopes for office buildings in subtropical climate zones

2016 ◽  
Vol 118 ◽  
pp. 214-225 ◽  
Author(s):  
Andrey A. Chernousov ◽  
Ben Y.B. Chan
2016 ◽  
Vol 27 (1) ◽  
pp. 47-58 ◽  
Author(s):  
Jie Jia ◽  
Wai-Ling Lee ◽  
Hua Chen ◽  
Han Li

Demand controlled ventilation (DCV) to conserve energy while maintaining an acceptable indoor environment has been used for over 30 years. However, little work has been done on evaluating its energy saving potential in cooling dominant office buildings in subtropical climate. In this study, the energy saving potential of DCV system for use in six representative office buildings in Hong Kong was investigated by simulations. Simulation validation was done based on in situ measurements and site surveys. The findings show that, based on their original design conditions, the use of DCV could lead to 12.5–26.1% energy saving. To facilitate quick estimation of the energy saving potential of DCV system, further simulations were performed for the development of a simplified model. The simplified model relates the energy saving potential to key air-conditioning system and design parameters. Based on the simplified model, sensitivity analysis was conducted to quantify the influences of different parameters on the energy saving potential of DCV system. The developed model method can be used for prediction on the energy saving potential in a wider application of DCV in Hong Kong.


Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1042 ◽  
Author(s):  
Shimeng Hao ◽  
Changming Yu ◽  
Yuejia Xu ◽  
Yehao Song

Achieving comfort in hot summer and cold winter (HSCW) climate zones can be challenging, since the climate is characterized by high temperatures in the summer and relatively colder temperatures in the winter. Courtyards, along with other semi-open spaces such as verandas and overhangs, play an important role in mitigating outdoor climate fluctuations. In this research, the effects of courtyards on the thermal performance of vernacular houses in HSCW climate zones were studied via field measurements and computational fluid dynamics (CFD) models. The selected courtyard house was a representative vernacular timber dwelling situated in the southeast of Chongqing, China. The indoor and outdoor air temperature measurements revealed that the courtyard did play an active role as a climatic buffer and significantly reduced the temperature’s peak value in the summer, while during the winter, the courtyard prevented the surrounding rooms from receiving direct solar radiation, and thus to some extent acted as a heat barrier. The contributions of thermal mass are quite limited in this area, due to insufficient solar radiation in winter and general building operations. The natural ventilation mechanism of courtyard houses in HSCW zones was further studied through CFD simulations. The selected opened courtyard was compared to an enclosed structure with similar building configurations. The airflow patterns driven by wind and buoyancy effects were first simulated separately, and then together, to illustrate the ventilation mechanisms. The simulation results show that the courtyard’s natural ventilation behavior benefited from the proper openings on ground level.


Author(s):  
Xuemei Su ◽  
Yibin Cheng ◽  
Yu Wang ◽  
Yue Liu ◽  
Na Li ◽  
...  

Few studies have been carried out to systematically screen regional temperature-sensitive diseases. This study was aimed at systematically and comprehensively screening both high- and low-temperature-sensitive diseases by using mortality data from 17 study sites in China located in temperate and subtropical climate zones. The distributed lag nonlinear model (DLNM) was applied to quantify the association between extreme temperature and mortality to screen temperature-sensitive diseases from 18 kinds of diseases of eight disease systems. The attributable fractions (AFs) of sensitive diseases were calculated to assess the mortality burden attributable to high and low temperatures. A total of 1,380,713 records of all-cause deaths were involved. The results indicate that injuries, nervous, circulatory and respiratory diseases are sensitive to heat, with the attributable fraction accounting for 6.5%, 4.2%, 3.9% and 1.85%, respectively. Respiratory and circulatory diseases are sensitive to cold temperature, with the attributable fraction accounting for 13.3% and 11.8%, respectively. Most of the high- and low-temperature-sensitive diseases seem to have higher relative risk in study sites located in subtropical zones than in temperate zones. However, the attributable fractions for mortality of heat-related injuries were higher in temperate zones. The results of this research provide epidemiological evidence of the relative burden of mortality across two climate zones in China.


Author(s):  
Yu.V. Chumak ◽  
H. A. Loban ◽  
M. M. Ananieva ◽  
M. O. Faustova

The recent development of technologies of the laboratory systems in microbiology, providing detailed genome sequencing, has paved the ways for isolating new pathogens and carrying out in-depth study of long-known microorganisms. Moreover, the progressing of science and technology contributes to study changes in the ecology of microorganisms and the epidemiological characteristics of their spreading over the world. These advances enable scientists to find out some "new" diseases, known as emergent infectious diseases. Emergent diseases have emerged as a new type of rapidly evolving, long-known infectious diseases. A prime example of an emergent infection is the Zika virus (ZIKV). ZIKV belongs to the family Flaviviridae of the Flavivirus genus. It was first isolated from the blood of a rhesus macaque in 1947 in East Africa (Uganda), in the Zika forest, where its name came from. A year later, in the same area, ZIKV was detected in mosquitoes of the Aedes africanus genus. For a long time following the initial isolation of ZIKV, isolated sporadic cases of the disease caused by this pathogen were recorded in Asia and Africa. In 2007, an ZIKV outbreak was reported on the island of YAP (Micronesia). This was the first outbreak outside Asia and Africa. Zika virus is primarily transmitted by the bite of an infected mosquito from the Aedes genus in tropical and subtropical regions. But according to literature data, this virus can be spread by 17 species of mosquitoes of this genus. AE. aegypti and Ae. Albopictus have been known a leading role of spreading the infection. Considering that these mosquitoes are not only carriers of ZIKV, but also some other flavivirusiv representatives, their wide geographical distribution has become an issue of great concern. AE. aegypti mosquitoes are thermophilic and live only in tropical and subtropical climate zones and this fact has played as significant rope in the ZIKV spread. Ae. albopictus mosquitoes promote the circulation of this pathogen and cause a rapid expansion of the virus in the world, since this species has become widely distributed in countries of subtropical and temperate climate zones. To date, besides the main vector-borne transmission of the virus, there are a number of reports about ZIKV transplacental transmission from an infected mother to the foetus. ZIKV caused viral infection during the pregnancy results in microcephaly, a congenital condition associated with incomplete brain development and abnormally small size of the skull. This viral infection can also lead to such complications as miscarriage, stillbirth, and premature birth. According to the literature, there is the connection between ZIKV and not congenital CNS abnormalities, but also with Guillain-Barre syndrome. There have been publications on not only ZIKV mosquito transmission and transplacental transmission, but a few reports on ZIKV sexual transmission when no barrier contraceptives are used. ZIKV can be isolated from ejaculate within 14-28 days from the onset of the first symptoms of the disease.


Yeast ◽  
2021 ◽  
Author(s):  
Peng‐Yu He ◽  
Xu‐Qian Shao ◽  
Shou‐Fu Duan ◽  
Da‐Yong Han ◽  
Kuan Li ◽  
...  

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