The understanding of adaptive thermal comfort is a key point to establish the appropriate balance between reductions in energy use and provision of comfortable indoor environment in buildings. Enough evidences have shown that tight control of indoor temperatures drives high energy costs and greenhouse gas emissions, and may not always provide benefit for occupant comfort and health. The concept of adaptive thermal comfort is regarded as a great contribution which may play an important role in low energy building design and operation.
How to develop an analytical and quantitative description of occupants’ adaptive thermal comfort in buildings is still a fundamental science question. Answering it will inform more appropriate design strategies, evaluation approaches, and control algorithms for indoor environment, all of which can reinforce reductions in building energy use. The IEA-EBC (International Energy Agency- Energy in Buildings and Communities Program) Annex69 project “Strategy and Practice of Adaptive Thermal Comfort in Low Energy Buildings” was established in 2015 and has been participated by over 30 institutes from 13 countries. During the past 3 years of working phase of Annex69 project, the international collaborative research team has worked on establishing a worldwide database with quantitative descriptions of occupants’ thermal adaptation, proposing how adaptive methods can be used in building design strategies to achieve thermal comfort with low energy use, developing new or improved indoor thermal environment criteria based on the adaptive thermal comfort concept, and providing guidelines for developing Personal Thermal Comfort Systems based on perceived/ individual control adaptation.