Light-weight materials are commonly used in high-rise buildings to reduce the building weight, but their thermal inertia will increase the fluctuation of air-conditioning and heating load and reduce indoor thermal comfort. Phase-change material (PCM) is employed to improve the thermal behavior by latent thermal storage, but its location has the obvious impact on the thermal behavior improvement of the light-weight wall. According to this condition, by taking the common multi-layer wall as a reference, three walls were built with different locations of the PCM layer, including locating the PCM layer in inner side, locating the PCM layer in outer side and distributing PCM uniformly into foamed concrete. The dynamic heat transfer model with the phase change was built and verified by an experiment. Numerical results showed locating the PCM layer in inner side is the best in three locations and followed by distributing PCM uniformly into foamed concrete, while locating the PCM layer in outer side is the worst in spite of the high liquid fraction variation. Locating the PCM layer in the inner side can lower the attenuation factor by 101.25% and 33.87%, increase the delay time by 40.00% and 17.14%, reduced by the peak heat flow by 47.69% and 17.28%, compared to locating the PCM layer in the outer side and distributing PCM into foamed concrete uniformly.

With the acceleration of urbanization throughout the world, climate problems related to climate change including urban heat islands and global warming have become challenges to urban human settlements. Numerous studies have shown that greenways are beneficial to urban climate improvement and can provide leisure places for people. Taking the coastal greenway in Qingdao as the research object, mobile measurements of the microclimate of the greenway were conducted in order to put forward an evaluation method for the research of outdoor thermal comfort. The results showed that different vegetation coverage affected the PET (physiologically equivalent temperature), UTCI (Universal Thermal Climate Index) as well as thermal comfort voting. We found no significant correlation between activities, age, gender, and thermal comfort voting. Air temperature sensation and solar radiation sensation were the primary factors affecting the thermal comfort voting of all sections. Otherwise, within some sections, wind sensation and humidity sensation were correlated with thermal sensation voting and thermal comfort voting, respectively. Both PET and UTCI were found to have a negative correlation with the vegetation coverage on both sides of the greenway. However, the vegetation coverage had positive correlation (R = 0.072) for thermal sensation and significant positive correlation (R = 0.077*) for thermal comfort. The paved area cover was found to have a positive correlation with PET and UTCI, while having a negative correlation with thermal sensation (R = −0.049) and thermal comfort (R = −0.041). This study can provide scientific recommendations for the planning and design of greenway landscapes to improve thermal comfort.

Under air-conditioning intermittent operation, there may be the large difference of air temperatures in two adjacent rooms due to different operation behavior, and thereby, interior envelops may cause great heat loss. Under this condition, floors may become the most vulnerable spot of the room heat preservation due to their large proportion in interior envelops and poor thermal insulation. To optimize the thermal performance of floors, three floor models were built to compare their thermal performance characteristics under air-conditioning intermittent operation, while a heat transfer model was built by the finite volume method and verified by experimental data. The results showed that an expanded polystyrene layer located close to the upper surface can improve the thermal performance of the bottom floor, while the continuous integration of an air space ceiling placed close to the lower surface can improve the thermal performance of the top floor obviously. The daily cooling load formed by the cast-in-place-reinforced concrete floor integrated with the expanded polystyrene layer and the air space ceiling can reduce the daily cooling load by 53.27% and 47.00%, compared with the cast-in-place-reinforced concrete floor and the cast-in-place-reinforced concrete floor only integrated with the expanded polystyrene layer.

Although occupants play a critical role in a building’s energy consumption, their air-conditioning use behaviour is often ignored, with it usually approximated as being a continuous operation. This in turn leads to a large difference between the actual and expected levels of energy consumption, raising the need to study air-conditioning use behaviour of building occupants. In this survey, 3083 questionnaires dealing with air-conditioning use behaviour were received from 34 cities distributed throughout China. The results show occupancy rates of 20% to 75% in residences and around 80% in office buildings during the period of 8:00–18:00. Air-conditioning use behaviour only meets a liveable requirement in residences and reaches a comfortable level in office buildings. This leads to daily air-conditioning operation times of between 0.85 and 4.31 hours in residences, and between 1.67 and 7.22 hours in office buildings, indicating most air-conditioning systems do not run continuously but intermittently, and that the assumption of continuous operation is far removed from reality. Based on these survey results, the large differences between the realistic (intermittent) and assumed (continuous) use of air-conditioning are employed to reveal the weaknesses in the present standards and to examine the optimization of building energy efficiency.