Retrofitting Strategies Based on Orthogonal Array Testing to Develop Nearly Zero Energy Buildings

Abstract

Retrofitting existing buildings to be a nearly zero energy building (nZEB) is an effective solution for greenhouse gas emissions and primary energy consumption reduction. A hybrid approach that integrates the building energy simulation method and orthogonal array testing (OAT) to renovate buildings to nZEB is proposed in this paper. Within a residential building in Changchun, Jilin of China, the total energy consumption index (TECI) and CO2 emission factor for heating are used as evaluation criteria. The reliability of the building energy model is validated and adopted to forecast the energy performance of different building renovation strategies. According to OAT, four passive measures can be ranked by their influence on TECI in descending order as follows: external wall heat transfer coefficient, airtightness, window heat transfer coefficient, and roof heat transfer coefficient. The optimal renovation solution of the studied building can reduce the TECI by 43.18% by only reducing the external wall heat transfer coefficient from 0.5 to 0.2 W/m2·K and the infiltration N50 from 3.6 to 0.4 ac/h. Besides, combined heat and power (CHP) utilities emit less CO2 than heat pumps in providing heating under the current CO2 emission factor of the power grid in China, making it impossible to give up district heating systems until carbon emissions of electricity generation have declined significantly. The results can provide a reference for the application of the nZEB standard in actual retrofitting projects.

Sustainable-Driven Renovation of Existing Residential Buildings in China: A Systematic Exploration Based on Review and Solution Approaches

“…Roof system retrofit program Roof renovation is crucial for reducing energy consumption and enhancing overall building performance, particularly in highly urbanized areas [43]. In roof renovation, insulation materials need to be installed considering the requirements of the roof structure [44], such as extruded polystyrene (XPS) [23,28], expanded polystyrene (EPS) [26], rock wool [31,32,45], and vacuum insulation panels [28]. Retrofitting the structural roof deck can meet the requirements of sustainable renovation, such as converting to a pitched roof to improve insulation and waterproofing performance [31].…”

“…They employ simplified room/zone thermal mass balance models and use accurate yet complex system models to depict the rapid dynamic response of each component under various control strategies. Another group, including EnergyPlus [25,28,31,35,36,44,64,67,68,70,72,76,[83][84][85][86], DeST [73,77], WUFI ® Plus [30], and IDA-ICE [74], focuses primarily on the long-term dynamic thermal performance of buildings and systems. Therefore, they utilize comprehensive room/zone models and simplified system models, making them more suitable for simulating the annual energy consumption of buildings.…”

“…In recent years, the construction industry has increasingly adopted new materials and technologies to reduce energy consumption, such as double-layered exterior walls [40], phase-change walls [40], and passive radiant cooling [23,28,31,32,36,40,41,44,51,63,66,78,85,91]. These advancements necessitate more accurate and specialized modules to achieve joint simulation between building energy simulation programs (BESP) and different modules.…”

“…However, they possess user-friendly features, making them convenient and suitable for architects and engineers in the building industry. Design-Builder is widely recognized as the most popular simulation software [23,26,28,31,32,42,44,45,53,65,68,76,83,88]. Additionally, Autodesk REVIT [42,87,[89][90][91] and SketchUp [67,72,86], as Building Information Modeling (BIM) software, are also commonly used.…”

“…phase-change walls [40], and passive radiant cooling [23,28,31,32,36,40,41,44,51,63,66,78,85,91]. These advancements necessitate more accurate and specialized modules to achieve joint simulation between building energy simulation programs (BESP) and different modules.…”