Experimental study on thermal characteristics of a double skin faade building

An experimental study of the thermal characteristics of an existing office building with double skin facade DSF were conducted in hot summer daytime in Nanjing China. The temperature distributions of the DSF and indoor environment were measured at different control modes of DSF.The results show that the energy consumption of the air conditioning system in room B with opened exterior vents a closed interior facade and an air cavity with shading was 21.0% less than that in room A with closed exterior vents a closed interior facade and air cavity without shading in 9.5 h. The temperature distributions of the DSF and indoor environment in both horizontal and vertical directions were decisively influenced by shading conditions. The usage of shading devices strengthens the stack effect on the air cavity. Compared to room A the temperature distribution in room B is more uniform with smaller fluctuations.Meanwhile the problem of overheating in the air cavity of the DSF is still present in all tested conditions.

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.

Double criterion optimisation of transparent facades based on solar thermal processes

This work aimed to find the best possible solution for transparent facades. The evaluation was formulated to assure the highest user comfort criteria corresponding to energy efficiency--two criterion optimisation. The analyses were based on BESTEST, south-oriented zone geometry. Computer model was designed using Finite Control Volume Techniques with assumptions for applied materials and specified boundary conditions, plus reference year for energy calculation （WYECZJ. The natural ventilation facade system was desfgned to determine airflow network inside the facade. The adjustable size of openings （inlets and outlets） was selected at the level of 80% for the cold season and totally dosed during the hot season. Environmental parameters for thermal comfort evaluation were： zone resultant temperature and solar radiation in zone space. Energy efficiency was assessed based on heat flux between the zone with controlled temperature and external environment. Results showed that well selected design of buffer zone section could improve energy efficiency of adjacent zones for both winter and summer periods. The most profitable Double Skin Facade solution is DGC （double glazing with low-e coating） combined with single glazing with internal blinds （SGB） or coloured glazing.

Numerical study of thermal characteristics of double skin facade system with middle shade

Architectural shade is an effective method for improving building energy efficiency.A new shade combined with the double skin façade(DSF)system,called middle shade(MS),was introduced and developed for buildings.In this paper,a 3D dynamic simulation was conducted to analyze the influence of MS combined with DSF on the indoor thermal characteristics.The research on MS for DSF involves the temperature,the ventilation rate,the velocity distribution of the air flow duct,and the indoor temperature.The results show that the angle and position of the shade in the three seasons are different,and different conditions effectively enhance the indoor thermal characteristics.In summer,the appearance of MS in DSF makes the indoor temperature significantly lower.The indoor temperature is obviously lower than that of the air flow duct,and the temperature of the air flow duct is less affected by MS.The influence of the position of blinds on indoor temperature and ventilation rate is greater than the influence of the angle of blinds.According to the climate characteristics of winter and transition season,in winter,early spring,and late autumn,the indoor temperature decreases with the increase of the position of blinds at daytime,but the opposite is true at night.The results found in this paper can provide reference for the design and use of MS combined with DSF in hot summer and cold winter zone.

Net-Zero Energy Building Enhancement for a Leadership in Energy and Environmental Design Platinum Educational Facility

In the United States, university buildings use 17% of total non-residential building energy per year. According to the NREL （National Renewable Energy Laboratory）, the average lifecycle of a building in a university is 42 years with an EUI （energy use intensity） of 23 kWh/m^2/y. Current building and energy codes limit the EUI to 16 kWh/m^2/y for new school buildings; this benchmark can vary depending on climate, occupancy, and other contextual factors. Although the LEED （leadership in energy and environmental design） system provides a set of guidelines to rate sustainable buildings, studies have shown that 28%-35% of the educational LEED-rated buildings use more energy than their conventional counterparts. This paper examines the issues specific to a LEED-rated design addition to an existing university building. The forum, a lecture hall expansion of to an existing building at the University of Kansas, has been proposed as environmentally friendly and energy-efficient building addition. Comfort and health aspects have been considered in the design in order to obtain LEED platinum certificate. The forum＇s energy performance strategies include a double-skin facade to reduce energy consumption and PV （photovoltaic） panels to generate onsite energy. This study considers various scenarios to meet NZEB （net-zero energy building） criteria and maximize energy savings. The feasibility of NZE criteria is evaluated for： （a） seasonal comparison; （b） facility occupancy; （c） PV panels＇ addition in relation to double skin facade. The results of NZEB approach are compared to LEED platinum requirements, based on Rol （return on investment） and PV panel＇s efficiency for this specific educational building.

Comparative Analysis of Two Energy-Efficient Technologies Used in the Shanghai Tower

Climate change continues to affect the lives of individuals across the world, creating a rise in demand for new technologies that can slow down the impacts of climate change. Shanghai, one of the largest cities in the world, has one of the highest carbon emission levels. In recent years, the research and development of energy-efficient technologies have gained more and more attention. The Shanghai Tower is a pioneer in green building design and a prominent example of Shanghai’s efforts towards low-carbon city development. In this paper, two technologies within the Shanghai Tower—ground source heat pumps (GSHP) and double skin facades (DSF)—will be analyzed. The paper will consist of firstly an investigation of the principles of the technologies, and then analysis, evaluation, and comparison of their respective characteristics. While both GSHP and DSF are used for sustainable purposes, the effectiveness of technologies depends on what environment the technology is used in and what purpose they serve. The evaluation of GSHP and DSF will be based on their performances under Shanghai’s climate and whether they contribute to the purposes of the Shanghai Tower.