Research on energy consumption of retrofitting existing office buildings toward the nearly zero energy standard in hot summer and cold winter areas

This paper explores energy-saving possibilities for heating and cooling as part of an existing office upgrade based on the nearly zero energy standard in the southern Chinese cities, such as Suzhou, where the climate is warm in summer and cold in winter. An international green building research center at Suzhou University was selected as the case study and reference model, which was created by the dynamic thermal simulation software OpenStudio. OpenStudio simulation software was used to set up a baseline model in reference to public building energy-saving design standards (GB 50189-2015), and a nearly zero energy consumption building model was set up based on the actual retrofitting situation. Based on the reference building, this study considers the insulating of the envelope, the airtightness of the building, the mechanical ventilation system, passive shading, and renewable energy utilization one by one, and verifies the effectiveness and feasibility of the transformation scheme. The design and practice of this research project can provide a reference for the nearly zero energy standard of existing office buildings in hot summer and cold winter areas.