Optimisation of the double skin facade in hot and humid climates through altering the design parameter combinations

Architects welcome double skin facade(DSF)due to its aesthetic quality.The first DSF structure was intended to prevent cold weather and strong winds.Nowadays,the application of DSF under different climates has been investigated in many previous studies.Fiowever,little work had been done on the behaviour of DSF in hot and humid climates.Therefore,this paper aimed to extend the application into this specific climate and Guangzhou was selected as the sample city.Both the climate and the design influence the performance of DSF.In this paper,rather than explore how each design parameter influences the performance,the design was evaluated from an overall aspect.The Designbuilder software was used to build the single skin facade(SSF)and double skin facade base model.Annual HVAC energy consumption for both the two models was calculated and compared.An optimisation process was conducted to figure out what kinds of parameter combination could make the design more energy-saving and thermally comfortable.The results indicated that it was possible to design an energy-saving DSF system applied in hot and humid climates compared with the SSF model.The efficiency of the DSF could be further enhanced with a better parameter combination.The optimised options had some features in common,which could provide some inspirations for the application of DSF in hot and humid climates.

Effects of water-cooled cover on physiological and production parameters of farrowing sows under hot and humid climates

The hot and humid climates,as encountered in the southern region of China with the open housing,can adversely impact the sows undergoing heat stress during the most vulnerable period at lactation.Hence,a water-cooled cover system(WCCs)for local cooling has essential practical value to improve productivity.The WCCs was developed for the sow crate of lactating sows separately,which performance was validated with the cooling efficiency in the sow occupied zone(SOZ)and physiological parameters.The results showed that the WCCs for the farrowing sows using aluminium plastic tubes connected in series could reach an appropriate cooling performance in adjacent units.The WCCs could decrease the SOZ air temperature by 3.0-4.5℃under the extremely hot climate when the indoor air temperature was 37℃,and maintain a suitable range(25-30℃)under the typical hot climate(<35℃).The respiration rate and skin temperature of farrowing sows had no significant difference between treatment group(WCC)and control group(sprinkle cooling)when the air temperature was below 30℃,but had a significant difference(p<0.05)when air temperature rose above 30℃.The control sows drank more during hot weather,and the feed intake was significantly lower than the sows with the WCCs(p<0.01).It was concluded that the WCCs could alleviate the heat stress of farrowing sows during typical hot climate.

Quantitative Analysis of the Outdoor Thermal Comfort in the Hot and Humid Summertime of Shenzhen, China

Outdoor thermal comfort has always been a major issue due to its irreplaceable role in maintaining good health and energy use. Thus,quantitative analysis of outdoor thermal comfort and discussions on influential factors seem very necessary to achieve the climate-conscious urban design. Therefore,an outdoor thermal comfort questionnaire survey and the simultaneous field measurement were conducted in six different places during the hot and humid summertime in Shenzhen. The results show that the overall weather conditions during the investigation can be expressed with high temperature and high humidity with strong solar radiation. The micro-meteorological parameters of six test sites vary greatly due to their different regional spatial layouts.Moderate range of air temperature( Ta) is between 28 to 30 ℃ while that of relative humidity( RH) mainly concentrates in 60%-70% with the thermal sensation votes. The main influential factors impacting outdoor thermal comfort are obtained and Tahas the greatest effect. The overall thermal comfortable ranges in Shenzhen are expressed by the range of 28. 14-32. 83 ℃ of PET and 24. 74-30. 45 ℃ of SET*. With the correlation analysis between the characteristic parameters of regional spatial layout and thermal climate and thermal comfort,it reveals that increasing the coverage ratio of water and green space( S) helps lower Taand increase RH. The global solar radiation( G) has a significant negative correlation with the height of buildings( H) and a positive correlation with sky view factor( SVF). Overall,reasonable configuration of the regional spatial layout contributes to providing a thermal comfortable environment.

Cooling load characteristics of indoor spaces conditioned by decoupled radiant cooling unit with low radiant temperature

Decoupled radiant cooling units(DRCUs)are capable of increasing the cooling capacity without increasing condensation risks even using a much lower cooling temperature than conventional radiant cooling units(CRCUs).However,it is unclear whether DRCUs using low radiant cooling temperature will increase the cooling load of the conditioned indoor spaces.In this study,the cooling load characteristics of a thermal chamber conditioned by a DRCU was investigated through developing a steady-state analysis model suitable for both DRCUs and CRCUs.The total/radiative heat flux,as well as the heat exchange with a thermal manikin and walls were analysed under different surface temperatures of DRCUs.The effect of the emissivity of the thermal chamber’external wall on the cooling load was also investigated.Results indicated that the cooling load under the DRCU was slightly smaller than that under the CRCU when the same operative environment was created.Decreasing the infrared emissivity of the exterior wall’s inner surface could lead to a significant decrease in the cooling load for both the DRCU and CRCU.By decreasing the wall emissivity from 0.9 to 0.1,the total cooling load of the DRCU can be decreased by 8.4%and the heat gain of the exterior wall decreased by 21.6%.This study serves as a reference for developing the analysis model and understanding the load characteristics when DRCUs are used to create the thermal environment for indoor spaces.