Building vertical greenery has become an effective measure to solve the contradiction between the shortage of urban greenery and the increasing demand for greenery. However, the lack of direct economic benefits dampens motivation for its development. As a vital development mode for high-density cities worldwide, commercial complexes are the most appropriate buildings to support greenery because of economic agglomeration and resource integration. An important reason for whether or not commercial complex greenery is constructed is the need for an evaluation system. To bridge this research gap, we propose a holistic evaluation guideline for commercial complex greenery. First, a list of related sustainable rating systems from the academic literature and official websites was compiled and reviewed to identify and compare their referential features. Second, the limitations of these evaluation systems in assessing the greenery of commercial complexes were explored using a case study. Third, the features of commercial complex greenery were introduced through field research and interviews. Finally, a holistic evaluation guideline for vertical greenery systems in commercial complexes was proposed, including logical thinking for the evaluation system of the dimension–indicator–quantitative method, the creation of innovative evaluation indicators, the establishment of a database, the assignment of weights to different dimensions and indicators, and the construction of an evaluation mechanism for the whole life cycle. This research demonstrates the significance of an evaluation process for commercial complex greenery systems, proposes a refined guideline for its development, and rationally grasps the development direction from a macro perspective.
In the north of China, during winter, a large number of activities (such as leisure, work, sightseeing and sports) are engaged in. This paper mainly focuses on human thermal perceptions of outdoor activities in a winter climate, especially the change in thermal perceptions when humans enter a temporary rest space with a shelter effect. A climate chamber was applied in our experiments, and temperature up-steps of 4, 8 and 12 °C were set, respectively. Twenty four college students were invited to engage in activities of different intensities, such as standing, walking (slowly) and biking. Through questionnaire survey and field measurement, the subjects’ thermal sensation, thermal comfort and skin temperature were obtained. Hypothesis testing and non-linear regression methods were introduced to analyze experiment data. Major results were as follows. After temperature up-step changes, thermal sensation and skin temperature reach steady state within 30 min. However, the change in skin temperature caused by a short-term thermal experience does not disappear completely within 40 min. In addition to the influence of ambient temperature changes, activity intensity also influenced the variation in thermal sensation (subjective) and skin temperature (objective). These study results provide a scientific reference for future research and design of a temporary rest space in low ambient temperatures. Experimental studies including broader age groups and outdoor field tests are valuable for future research.
Heating systems are essential municipal infrastructure in winter, especially in severe cold cities of China. The safety and efficiency of heating systems greatly affect building energy efficiency and indoor thermal comfort. Heating networks (HNs), playing the role of transportation, are the key parts of heating systems. In HNs, hydraulic models could be affected by the accuracy of resistance characteristic parameters, which are expressed by pipe friction parameters (PFPs) in this paper. As the uniqueness of the estimation results of PFPs has not been discussed in previous studies, this paper builds an estimation method of PFPs by dividing two types of pipes, substituting variables and establishing a split-step linearization method. Combining with the theory of matrix equations, the decision conditions and solution methods for obtaining the unique estimation results of PFPs are determined. Theoretical analysis and case study results show that estimation values of PFPs can be obtained by utilizing measured data under multiple hydraulic conditions. In the example of DN and the simple actual HN, the average estimation deviation of PFPs is 1.42% and 1.86%, which are accurate enough for actual engineering. Estimation results of PFPs obtained by this method guarantee the accuracy of analysis and regulation in heating systems and improve social energy utilization efficiency.