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Escalating global climate change and the intensification of urban heatwaves have led to an increase in summer air conditioning cooling energy consumption. This phenomenon is particularly critical in tropical regions, as it may trigger an energy crisis. The rational setting of indoor thermal design parameters can help conserve energy to the maximum extent while ensuring thermal comfort for occupants. This study selected Haikou City, a unique tropical city in China, as the research location. Indoor environment measurements and a questionnaire survey were conducted with participants, and the outdoor thermal environment sensitivity, population attributes and differences in thermal sensation, thermal neutral temperature, and comfort range were calculated and analyzed. The following results were obtained. Based on the overall population, long-term residence, and temporary residence classification, the indoor thermal comfort needs of residents in tropical cities in Haikou were effectively identified. The actual thermal neutral temperature of the overall population is 25.7 °C, and 90% of the acceptable thermal comfort temperature range is 23.2 °C–28.0 °C. The actual thermal neutral temperature of the regular residents is 27.3 °C, and 90% of the acceptable thermal comfort temperature range is 23.3 °C–31.4 °C. The actual thermal neutral temperature of the temporary population is 25.5 °C, and 90% of the acceptable thermal comfort temperature range is 23.0 °C–28.0 °C. These research results have an important reference value for improving the setting of the temperature of air conditioning in tropical areas in summer and further reducing energy consumption, which is conducive to sustainable development. [ABSTRACT FROM AUTHOR]

This paper is devoted to the analytical study of the long-time asymptotic behavior of solutions to the Cauchy problem of a system of conservation laws in one space dimension, which is derived from a repulsive chemotaxis model with singular sensitivity and nonlinear chemical production rate. Assuming the H2-norm of the initial perturbation around a constant ground state is finite and using energy methods, we show that there exists a unique global-in-time solution to the Cauchy problem, and the constant ground state is globally asymptotically stable. In addition, the explicit decay rates of the solutions to the chemically diffusive and non-diffusive models are identified under different exponent ranges of the nonlinear chemical production function. [ABSTRACT FROM AUTHOR]

Abstract Phase change material (PCM) have been explored for different applications to increase the energy efficiency and economy. However, the proper PCM selection to meet given requirements generally requires that a compromise is struck between conflicting criteria. This paper attempts to extend multi-criteria decision making (MCDM) method to solve the PCM selection problem. Firstly, the comprehensive appraisal indexes model is established and the subjective and objective weight of the criteria are obtained based on the analytic hierarchy process (AHP) and entropy information method, respectively. Secondly, the optimized combination weight method is adopted to obtain the combination weight. Then, the pre-screened PCMs are ranked using technique for order performance by similarity to an ideal solution (TOPSIS). Finally, the information retrieval is employed to justify the rankings. To demonstrate the applicability of the proposed method, a problem to select the optimal PCM for ground source heat pump (GSHP) integrated with phase change thermal storage (PCTS) system is considered. The result showed that Ba(OH) 2 ·8H 2 O is the best material for the given case and the GSHP integrated with PCTS system has better economic performance compared to the GSHP system, meanwhile, the proposed method is a simple and practical approach in solving the PCM selection problem. Highlights • Establish the comprehensive appraisal indexes model for PCM selection. • Apply the optimized combination weight method to PCM selection. • Examine the ranking goal by information retrieval. • A case study is provided to show the applicability of the proposed method. [ABSTRACT FROM AUTHOR]

Integrating combined cooling, heating and power (CCHP) system with biomass gasification is a sustainable distributed energy system to effectively utilize biomass resource and improve energy efficiency. In order to achieve a higher energy efficiency and more cost-effective operation, a thermoeconomic cost analysis method based on the exergetic cost theory is applied to the CCHP system based on biomass gasification. Firstly, the exergetic cost and thermoeconomic cost of all flows in the system are calculated in different operation modes. Moreover, a sensitivity analysis is presented to obtain the thermoeconomic cost variations of the products along with the influence factors, such as service life, interest rate, operation hours and biomass cost. The results indicate that the unit exergetic cost of electricity is 4.447, 4.445 and 4.447 for the summer, winter and transition season operation conditions, whereas the thermoeconomic cost is 240.004RMB/h, 257.905RMB/h and 270.811RMB/h, respectively, while for domestic hot water, these values are 14.822, 14.817, 27.086 and 33.361RMB/h, 35.769RMB/h, 166.284RMB/h, respectively. The unit exergetic cost of water for cooling and heating is 8.804 and 7.465, the thermoeconomic cost is 138.807RMB/h and 147.454RMB/h, respectively. From the sensitive analysis, the biomass cost is the most sensitive factor to the thermoeconomic cost of the products. The results also reflect that a combination of the thermoeconomic cost based on exergetic cost and sensitivity analysis method is a powerful and efficient tool for evaluating the performance of multi-product energy system. [ABSTRACT FROM AUTHOR]

Building energy conservation has been a globally important issue not only because of the greenhouse gas emissions that occur during the construction and operation of a building, but also due to the increasing emphasis on indoor thermal quality, which is directly related to the quality of life, especially in northern China. The behaviors of heating companies and building users are considered to play important roles in the reduction of building energy consumption. However, it is necessary to understand the relationship between the heating fee, which represents the heating policy, and the energy performance, which considers both the actual energy consumption and thermal ability of a building. With this goal in sight, this study focuses on residential buildings in a climate zone that experiences quite low temperatures, and the heating energy consumption of 40 residential buildings from five typical regions in Inner Mongolia were monitored and analyzed. The thermal comfort, occupant behavior, and heating energy consumption of typical households and buildings in these regions were quantified. In view of the monitored results, building models were built and validated, with the results treated as training samples in clustering and classification procedures. For the sake of the further formulation of a heating energy cost allocation policy, the K-means clustering algorithm and discriminant analysis (DA) were used in this work to evaluate and group residential buildings according to their heating energy consumption and thermal-physical properties of the envelopes. The results of this study indicated the existence of regional heating energy consumption differences. Moreover, the main influential factors for grouping residential buildings and the number of clusters were suggested based on the K-means clustering algorithm and DA method. Meanwhile, the classification accuracy rate obtained from the DA method not only verified the clustering results, but also confirmed the further applicability of the combination of these two methods. [ABSTRACT FROM AUTHOR]

Back propagation neural network (BPNN) models and multiple linear regression (MLR) models are widely used to predict heating energy consumption. To improve the prediction accuracies for the BPNN and MLR models, we propose a novel sample data selection method (SDSM) combining the similar days selection with the virtual samples generation. First, a grey correlation method integrated with an entropy weight method is given to optimize the similar days selection. Then virtual samples are generated by Gaussian distribution function based on the similar samples. Finally, a new sample set (including similar and virtual samples) is obtained, and then, it is regarded as the input variable for the BPNN and MLR models. The results show that training errors and prediction errors are obviously reduced in the developed BPNN model. Although the prediction accuracy of the developed MLR model is improved by different degrees, the coefficient of determination obtained in the regression fitting process is poor. It is proved that the novel SDSM is applicable only for the BPNN model, but not for the MLR model. [ABSTRACT FROM AUTHOR]

Inner Mongolia locates in the very north of China, where there always be quite cold in winter. As a result of emphasizing on high indoor temperature, large amount of heating energy had been consumed in the past decades. In this research, the influence of occupant behavior, for instance, the dressing habit, window opening behavior and consumption customs on building heating energy consumption had been investigated. Field investigation, with the aid of other methods, such as design scene investigation method, are firstly prepared to be taken advantage of to seek out the information related to occupant behavior modes. Secondly, indoor and outdoor related environmental parameters of typical buildings were monitored. By means of our research, two typical behavior characteristics of Inner Mongolia occupants were found: 1) People opened windows for cooling purpose in winter; 2) They got accustomed to wear light in home as well as dissatisfied with comparatively proper indoor temperature admitted by national standard. The reason for that can be attributed to the inefficient heating cost allocation method, which should be further retrofitted in order to stimulate occupant energy conservation awareness. [ABSTRACT FROM AUTHOR]

The efficient lighting project, aiming at developing and promoting energy-efficient lighting products, has been initialized in China since 1996. The use of energy-efficient lighting products is one of the best and most cost-effective ways of reducing lighting energy consumption. Great attention has been put into this project and effects have been made nationwide. But no effective evaluation system has been established yet, which makes the summary of experiences and lessons less systematic and the improvement of future work quite difficult. Based on the Analytic Hierarchy Process, this paper established a new evaluation system of promotion effects after taking the public policies and practical situation in China into consideration. Aspects of environment, economy, adequacy, and technology were considered comprehensively in the evaluation system to score the promotional effects. The efficient lighting project during the 11th Five-Year period (2005-2010) in China was examined to prove the feasibility of the evaluation method. A 'proper' level was finally rated based on the evaluation results, which meant that the promotion of the study case was fruitful on the whole. Benefits such as the evident improvement of energy efficiency and the weak points of producing enterprises were both discovered. Relevant to the problems and experiences, suggestions for the future work were also proposed for the efficient lighting project in China. [ABSTRACT FROM AUTHOR]

• A net zero energy wooden structure building in severe cold zone was designed in severe cold zone. • A new type of water-passing wall was designed and applied in the wooden structure building. • Renewable energy systems are adopted to pursue net zero energy consumption for wooden structured buildings in severe cold areas. • Study on the operational performance of wooden structure building. • Evaluated the energy criteria and economy of the wooden structure building. At present, there is no lack of research on net zero energy buildings (nZEB) in China, and most of the research on "nZEB" focuses on buildings using traditional building materials like rebar concrete, brick, etc. In this paper, we take a wooden structure residential building in the severe cold zone as the research object, design a new type of water-passing wooden structure wall, and explore how to achieve net zero energy consumption through appropriate methods in the design stage. During the operation of the wooden structure building throughout the year, the solar photovoltaic (PV) system provides electricity to the building. In the heating season, we will supply groundwater or shallow geothermal water into the water pipes in the wall, and the solar thermal system provides hot water for heating. According to the whole year operation of the wooden structure building, the indoor environment meets the requirements of comfort standards, and the designed envelope structure of the wooden structure building has an excellent thermal performance. The energy consumption was reduced by 62.9% compared with energy-saving buildings without water-passing walls. The electricity generation capacity of the solar PV system is more than the actual electricity consumption of the building, the energy criteria are met the relevant requirements of the net zero energy building, and its economy is also evaluated. [ABSTRACT FROM AUTHOR]

Abstract: Improving the energy performance of building envelope is a key to promote building energy efficiency. As a part of building envelope, Windows are recognized as the weakness of building envelope in reducing building energy consumption and thus should be as more energy efficient as possible. Currently available window products, such as double-glazed windows and tinted double-glazed windows, have their limits in balancing the performance of indoor thermal environment, energy and daylight. However, thermotropic materials, which change their light transmission behavior reversibly, have a great potential in achieving an excellent comprehensive performance. Therefore, this paper carried out energy, daylight and indoor thermal environment simulations to investigate the performance of a developed novel kind of thermotropic material for energy-efficient windows using the building simulation software DeST. Results show that thermotropic double-glazed windows can reduce 70% and 53% of highly uncomfortable indoor thermal environmental conditions in west-facing room, respectively, compared with double-glazed windows and tinted double-glazed windows. Moreover, they can reduce 19% of cooling electricity requirements in west-facing rooms compared with double-glazed windows, and provide an appropriate indoor illumination condition. [Copyright &y& Elsevier]

Abstract: The purpose of this paper is to investigate the reasons for ever growing energy consumption in buildings and to give enhanced supervision strategies for reduction of building energy consumption compared to regular ones. A case study of Ningbo city was used to make a detail analysis. Several factors were determined as the reasons for ever growing building energy consumption including climate change, household electricity load increase, the growth of real estate, fast-growing household electrical appliances, high energy consumption in existing buildings, changes in industrial structure and the lack of enhanced government supervision. Then the discussion of suitable countermeasures shows that only enhanced supervision strategies are currently applicable. Finally, it is concluded that enhanced government supervision strategies, including the establishment of a strict control system for new built buildings through information integration and encryption, establishing an energy efficiency supervision system of large-scale public building and a carrot-and-stick approach with added expert checklist for the building application of renewable energy, showed great advantages in promoting building energy efficiency in Ningbo, compared with other cities. These supervision strategies are applicable in other cities as they are in the similar situations in the enforcement of building energy efficiency. [Copyright &y& Elsevier]

Current studies demonstrate that uniformly stable indoor thermal environments do not completely ensure the thermal comfort of residents, and unreasonable temperature settings can cause discomfort and high energy consumption. Moreover, temperature ramps frequently occur in actual indoor environments. Thus, it is important to understand human thermal responses in moderate environments with temperature ramps to improve working conditions and reduce energy consumption. In this regard, an experiment using within−subjects design in a chamber was conducted to evaluate the effects of temperature ramps on human thermal responses. A total of 60 healthy participants (30 females and 30 males) were recruited to participate in the tests. Their subjective responses, thermal comfort and sensation, thermal acceptability and preference, humidity perception and facial thermal sensation were collected during the experiments. The results showed that temperature ramps significantly affected the thermal sensation, thermal comfort, and facial sensation in the ramp-down environments but not significantly in ramp-up environments. However, the effect of temperature ramp-down on the humidity sensation was only significant for the female participants. A 2 °C temperature ramp-up did not affect the thermal comfort of the participants and was acceptable for them. The male participants were more receptive to ambient temperatures than the female ones, whereas the female participants were more sensitive to cool environments than the male ones. Moreover, good fitting relationships between the thermal sensation and the thermal comfort, as well as the thermal sensation and the facial thermal sensation were observed. This study provides some references for the influence of temperature ramps on human thermal responses in actual indoor environments, and recommends temperature set points to reduce the use of cooling energy. • Temperature ramp direction significantly affects thermal sensation and comfort. • Thermal sensation varies linearly with facial thermal sensation. • Regression relationship is obtained between thermal sensation and comfort. • Appropriate temperature ramp-up range is recommended for comfort and energy saving. • Gender differences are prevalent in subjective responses and should be considered. [ABSTRACT FROM AUTHOR]

Some studies revealed that steady-uniform thermal environments are not the optimal environmental state to ensure thermal comfort, and temperature ramps offer potential advantages over traditional air conditioning methods. Moreover, when exposed to the same environmental conditions, gender differences in thermal responses were often observed, but the gender differences in the ramped conditions and causal relationships remain unclear. Therefore, an experimental research was conducted in a chamber by controlling the rates and directions to study the gender differences in thermal responses to temperature ramps. Three temperature ramps conditions (A: 26 °C−24 °C−26 °C; B: 26 °C−28 °C−26 °C; C: 26 °C−30 °C−26 °C) were investigated with 60 healthy participants (30 females and 30 males) recruited. The main conclusions indicated that women are more sensitive to temperature ramp-down environments than those of their male counterparts. Direction of temperature ramps had a significant effect on human responses in cool environments but no effect was observed in warm environments. Moreover, there was no significant differences in subjective responses between genders in a 2 °C ramp-up environment from 26 °C to 28 °C. Due to psychological differences, men have a wider range of temperature acceptability than women. Furthermore, the relationships between thermal sensation and thermal comfort, thermal sensation and thermal acceptability were also established, indicating that thermal sensation had significant impacts on other psychological responses. This paper has reference value for related researchers and designers to take temperature ramps and gender differences account in the design of indoor thermal environments, which benefits to improve thermal comfort, health and energy efficiency. • Thermal experience, rates and directions of temperature ramps have different effects on subjective perception. • Women are more sensitive to temperature ramp-down thermal environments than men. • Significant differences are only observed in thermal responses between genders in the ramp-down environments. • The acceptable temperature ramps ranges of women are smaller than those of men. • Relationships between some thermal responses are observed after temperature ramping. [ABSTRACT FROM AUTHOR]

Promoting energy efficiency (EE) requirements for new residential buildings has been proven to be an effective way to slow down the rapid increase of energy consumption. Its successful implementation relies significantly on the attitudes and participation of various stakeholders within the industry, yet they are normally taken for granted. This paper explores and reports both the consensus among and the diversity of the attitudes of frontline stakeholders toward future EE requirements in the new residential building sector via a nationwide Delphi questionnaire distributed to 29 institutes and 25 experts. Results indicate that promotion of approximately 30% EE every five years until 2030 is suggested and that 20% EE promotion every five years is the most likely to be achieved. In addition, China should progressively adopt the energy intensity index into the current building EE evaluation system. This paper also gives a detailed description of opinions from frontline stakeholders. The findings are expected to help researchers and policymakers better understand the true attitudes of stakeholders, thereby enabling the formation of a proper outlook for new residential building EE promotion. [ABSTRACT FROM AUTHOR]

The energy-efficiency promotion of new residential buildings in China has achieved great progress in the past three decades. However, the expected policy outcomes cannot be fully achieved due to the barriers in the policy-making and implementation process. Whereas governments play a critical role in policy formation, perceptions of stakeholders involved in the building life cycle and the industrial value chain (such as developers, design institutes and relevant material manufactures) are fundamental to the successful implementation. To collect and identify the barriers of significant influence on the industry from stakeholders' perspectives, this paper used a nationwide institutes' questionnaire to collect stakeholders' voices regarding the barriers, the corresponding popularity and the severity. All the barriers were categorized according to institutions' scorings through cluster analysis. The relationships between barriers were also analyzed according to the framework based on policy cycle and policy environment. Results indicated that the core problem is the ineffectiveness translating energy savings into benefits and profits. Accordingly, three major barriers were identified, namely the (1) unsatisfied policy design and implementation; (2) stakeholders' lack of implementation capacity in developing and constructing high-performance new residential building projects and adopting relevant technologies; and (3) insufficient legalization of relevant market. Other identified barriers either were those not agreed by all institutions, or those could be eliminated easily after the removal of the above three barriers. [ABSTRACT FROM AUTHOR]

Nationwide energy efficiency (EE) promotion of new residential buildings is affected by multiple factors regarding policies, markets, technologies, capacities, and economics. The perceived influences of these factors by stakeholders are crucial to the effectiveness evaluation of current policies and the selection of policy instruments. However, they are normally assumed or taken for granted. The knowledge gap between stakeholders' perceptions and research assumptions may lead to researchers' recognition bias. Correspondingly, this paper aims to identify the significant factors, perceived by frontline stakeholders, influencing nationwide EE promotion of new residential buildings before 2020 and 2030. Factors were collected through literature review and their influence were evaluated via Analytical Hierarchy Process based on the data collected in the questionnaires distributed to 32 institutes. The theory of Nested Policy Design Framework and Policy Environment was used to structure the hierarchy and generate policy implications. Results indicate that (1) policy factors are of the greatest influence before 2020 and market perfection factors will have great influences from 2020 to 2030, indicating the transformation of governance arrangement to "market-based" and "network-based" from the current legal-based system; and (2) factors regarding market needs are of significant influence in both terms, revealing the way the transformation should be accomplished. [ABSTRACT FROM AUTHOR]

Abstract: The establishment of energy consumption quota is an important project for promoting the development of building energy efficiency in China. This research focused on the establishment of energy consumption quota of four and five star luxury hotels in Hainan Province, one of the international traveling destinations. Firstly, the theoretical analysis of energy consumption quota included data acquisition, normalization of energy use index and the statistical analysis methods for the calculation of the energy consumption quota. Subsequently, detailed information of 19 hotels plus general energy consumption data of 54 hotels was treated as the sample data for calculating energy consumption quota. According to correlation analysis, energy consumption per unit area was identified to be the most suitable index to represent the energy consumption level, and was combined with the energy consumption normalized by degree-day method to obtain the normalized energy use index (EUInorm). Also, the energy consumption quota interval of four and five star luxury hotel buildings in Hainan in the initial implementation stage was identified as 69.23–96.75kWh/m2 in accordance with comparison of the results calculated by statistical methods. Finally, proposals were put forward about the implementation of building energy consumption quota. [Copyright &y& Elsevier]

Abstract: Accurate energy saving effect evaluation analysis of building energy efficiency retrofit is of benefit to obtain technology optimization and fast return of investment. According to the implement sequence, evaluation methods can be divided into post evaluation and prediction evaluation. The energy saving effect of an air-conditioning system retrofit project was analyzed by these two models respectively. The post evaluation model was built based on the spot test data and a parameter called as Refrigeration Operation Energy saving Effect Ratio (ROEER). The prediction evaluation model was built based on Back-Propagation Artificial Neural Network by the use of MATLAB Neural Network Toolbox. The comparison result between these two kinds of evaluation models match well with each other. These two models can be used to predict and evaluate energy saving effect of air-conditioning system retrofit to further improve the real energy saving effect of building energy efficiency retrofit. [Copyright &y& Elsevier]

Abstract: According to the requirement of Chinese National Policy of energy efficiency and emission reduction, optimized retrofit on the air-conditioning system of existing building is not only a measure to improve the building energy efficiency but also an important part to implement the emission reduction. This article put forward pertinent retrofit schemes after conducting analysis on the air-conditioning system of an industrial enterprise. With comparing the feasibility and the prospective effect of each retrofit scheme, the better one was determined. [Copyright &y& Elsevier]

In order to realize sustainable development of the whole economic society, the evaluation of the energy efficiency level of energy consumption sectors (ECSs) is urgent and necessary. This study elaborated the concept of the energy efficiency improvement from the perspective of whole society to establish a macro-evaluating system (MES). Industry, transport, civil buildings are the three major ECSs in China at present. By analyzing the status of each energy consumption sector (ECS) and the relative energy efficiency technologies, a hierarchical evaluation model, including evaluation factors, sub-factors, weights for each factor and sub-factor, was proposed for each ECS. With the help of the Analytic Hierarchy Process with Delphi (AHPD) and Grey Correlation Degree (GCD) method, the comprehensive scores, namely, the weighted incidence degree was obtained. Three cases in Tianjin, China were taken as examples to prove the feasibility of the evaluation system. Typical cities, including Shenyang, Beijing, Wuhan, Guangzhou, Chengdu, Xi'an, located in different regions of China were evaluated and compared. Results demonstrated that the technical level was mainly influenced by policy and economic level. Recommendations for energy efficiency policy making and energy efficiency targets allocating were proposed for regions based on the evaluation results. [ABSTRACT FROM AUTHOR]

The energy performance of a ground-source heat pump (GSHP) system will gradually deteriorate and the annual operation cost will increase annually if the heat injected into and extracted from the underground soil is imbalanced. To solve the underground heat balance problem and improve the energy efficiency of the system in the long-term, a temperature difference control strategy for the GSHP system coupled with borehole free cooling (BFC) is proposed in this study. An office building located in Tianjin is selected as a case study. According to the established simulation models by Designbuilder and TRNSYS, measured data is used for validation. The new control strategy and two other contrasting control strategies are validated with TRNSYS. The results show that free cooling with borehole water matches the indoor air parameter with the design indoor conditions and also improves the average annual cooling efficiency of the GSHP system to 16.22. Moreover, the underground soil heat imbalance can be improved, and the average annual energy consumption and operation cost can be decreased to 55.9% and 56.0%, respectively. The proposed control strategy has the potential to improve heat imbalance and reduce energy consumption and operation cost for GSHP systems. [ABSTRACT FROM AUTHOR]

Abstract: Indoor design air parameters regulated in current design standards are set on the basis of human thermal comfort without fully considering the building energy efficiency. This article analyzed the indoor design air parameters with investigation study and simulation study respectively from both views of thermal comfort and energy consumption. By conducting field testing in existing buildings and collecting design information from blueprints and description files, indoor air parameters of 140 public buildings in China were investigated. Typical public buildings (small office building, large office building and shopping mall) were selected for simulation study. Simulation models for three types of public buildings were established based on the investigation results in order to have assumptions better fit the actual situations. The relationship between PMV (predicted mean vote) and energy consumption of the simulation models was analyzed. From the analysis of the results of investigation and simulation, it could be seen that the design relative humidity in winter hardly influences the indoor thermal comfort and building energy consumption, while design relative humidity in summer, indoor air temperature and PMV values were all related to indoor thermal comfort level and building energy consumption. Recommend indoor design air parameters that contribute relatively low energy consumption and high comfortable level were also put forward to improve the current design standards. [Copyright &y& Elsevier]

Abstract: Geothermal energy has been successfully applied in many district heating systems. In order to promote better use of geothermal energy, it is important to analyze the operation strategy of geothermal heating system. This study proposes a comprehensive and systematic operation strategy for a geothermal step utilization heating system (GSUHS). Calculation models of radiator heating system (RHS), radiant floor heating system (RFHS), heat pump (HP), gas boiler (GB), plate heat exchanger (PHE) and pump are first established. Then the operation strategy of the GSUHS is analyzed with the aim to substantially reduce the conventional energy consumption of the whole system. Finally, the energy efficiency and geothermal tail water temperature are analyzed. With the operation strategy in this study, the geothermal energy provides the main heating amount for the system. The heating seasonal performance factor is 15.93. Compared with coal-fired heating, 75.1% of the standard coal equivalent can be saved. The results provide scientific guidance for the application of an operation strategy for a geothermal step utilization heating system. [Copyright &y& Elsevier]

Abstract: Hainan province is the only tropical and island province in China, with the unique climatic and geographical features. It has a different energy performance in public buildings from those in the inland areas. This paper investigated the current situation of energy consumption of the sampled public buildings, including 26 hotels, 24 office buildings and 7 department stores, through analyzing utility billing data, on-site survey and measurement, and site operational records. The breakdowns of energy consumption found out that the electricity dominated the energy consumption for all the sampled buildings and the air conditioning system played a key role in the energy consumption of major building services. By analyzing the main factors for building energy consumption, the annual average energy use indexes were calculated to be 141.63kWh/m2, 87.70kWh/m2, and 166.95kWh/m2 for hotels, office buildings and department stores, respectively. Besides, the comparison between Hainan province and other areas revealed that the building energy consumption of this tropical province was at a low level. Because indoor environment quality can influence the health and work efficiency of humans in buildings, field tests on the indoor environment quality were also carried out, and the performance of indoor environment quality was rated. [Copyright &y& Elsevier]