The Use of Horizontal Shading Devices to Alleviate Overheating in Residential Buildings in the Severe Cold Region and Cold Region of China

Abstract

Global warming is resulting in higher summer indoor temperatures in the severe cold region and cold region of China, and this is affecting thermal comfort. Local building design codes consider these regions as cool in summer, and do not consider the phenomenon of overheating or propose countermeasures. This paper studied the possibility of overheating in residential buildings in these areas. It suggested alleviating this phenomenon using external horizontal shading, and discussed how to integrate thermal comfort into the building design and save energy consumption. The IESVE software was used to simulate 18-storey residential buildings with natural ventilation in Yichun, Harbin, Shenyang, Dalian, and Beijing, and to calculate the change in indoor operative temperature. Horizontal shading was designed for case study building to attempt to alleviate the overheating phenomenon in summer. The results showed that the case study building in the five cities experienced different degrees of overheating. External horizontal shading was successful in reducing indoor overheating, especially in the severe cold B and C zones and the cold A and B zones. The relevant building codes should be modified to take this into account. Reasonable design of horizontal shading can effectively reduce energy consumption, particularly when compared with air-conditioned buildings.

Assessing the Potential of Integrated Shading Devices to Mitigate Overheating Risk in University Buildings in Severe Cold Regions of China: A Case Study in Harbin

“…Similarly, simulations by Camacho Montano et al [19] showed that overheating of the studied school buildings in the UK represents up to 27% of the occupied time. In the severe cold regions of China, an increasing amount of indoor temperature monitoring data warns of regional overheating risks [20,21], and the risk of overheating in residential buildings has been tentatively confirmed [22][23][24].…”

“…There are two main types of measures to mitigate summer overheating: active interventions in building systems, such as ventilation systems, and passive performance optimisation of buildings, including modifications to the performance of the building envelope [28][29][30], natural ventilation [31][32][33], and shading devices [17,22,34]. Controlling solar gain can be effective in reducing overheating in summer.…”

A multi‐objective optimization approach to designing window and shading systems considering building energy consumption and occupant comfort

“…As a result, energy consumption was reduced by 77%, while thermal and visual comforts were improved 60 . When horizontal shadings were employed in an 18‐story residential building with natural ventilation, an 18.5% reduction in total overheating was achieved, directly impacting building energy consumption 61 . In a study conducted in the USA, two researchers investigated a prototype of switchable insulated shading (SIS) systems to maintain occupant thermal comfort while reducing building energy consumption.…”

“…60 When horizontal shadings were employed in an 18-story residential building with natural ventilation, an 18.5% reduction in total overheating was achieved, directly impacting building energy consumption. 61 In a study conducted in the USA, two researchers investigated a prototype of switchable insulated shading (SIS) systems to maintain occupant thermal comfort while reducing building energy consumption. It was found that this value correlated linearly with the slat angle, and using the SIS system may reduce HVAC energy use by up to 11.4% in different cities.…”

Design of external shading devices in Mansehra, Pakistan and their role in climate change

“…Solar shading mechanisms modify heat exchanges through the glass building envelope, minimize annual solar gains, and vary daylight levels in a structure as well as the view to the outside environment. Therefore, shadings affect how much energy is used for lighting, heating, and cooling a structure, as well as its occupants' visual and thermal comfort (Xu et al, 2022). The wall surfaces that receive the shading devices might be internal or external (Mohammed et al, 2022).…”