Research on energy-saving factors adaptability of exterior envelopes of university teaching-office buildings under different climates (China) based on orthogonal design and EnergyPlus

To achieve carbon neutrality in 2060 (China), building energy-saving has been highly concerned. University buildings have great energy-saving potential as part of energy consumption where 70% of energy loss is caused by heat transfer from the envelope. However, most of the research on energy-saving factors for envelopes is limited to a certain climate or a specific building type, and the optimal configuration of envelopes under different climatic regions has not been well solved. Therefore, the influence degree and appropriate parameters of each factor of the teaching-office building envelopes on energy consumption under different climates were analyzed in this paper by orthogonal design and numerical simulation. Results show that: (1) Solar heat gain coefficient (SHGC) and indoor air change rates (ACH) [the heat transfer coefficient of the exterior wall (K_wall) and ACH] are the main factors affecting the cooling [heating] load, the insulation form of the exterior wall (W_ins) and K_wall [W_ins and solar radiation absorption coefficient of exterior surface materials (ρ_s)] have less influence; (2) The important ranking and optimal level of the influence of each factor on the cooling (or heating) loads are related to local load demands; (3) For the annual load, K_wall and the heat transfer coefficient of the exterior window (K_win) is the focus of energy-saving in severe cold and cold zones, but their impact is not significant in Guangzhou and Kunming, and the high significance of SHGC is only shown in Hohhot, Lhasa, Guangzhou, and Haikou; (4) The annual load energy savings reach 39.64%–57.57% in different climates by optimizing all factors. The research results can provide directions and data references for the energy-saving design and renovation of educational building envelopes in different climates (China).