Different Climate Zones In China Research Articles

A new TMY generation method based on the entropy-based TOPSIS theory for different climatic zones in China

Typical meteorological years (TMY) serve as basic parameters for building energy consumption simulation and play a key role in building energy-saving design. At present, the most widely used method for generating TMY is the Finkelstein–Schafer statistical method of Sandia Laboratory in the United States. However, when this method is used to generate TMY, all meteorological parameters use a uniform weighting factor which fails to reflect the different regional climate impact differences. It is unreasonable to adopt a unified weighting factor, because the meteorological resources of different climate zones are very different, and the leading role of building energy consumption is different. This paper proposes a new method, applying the entropy-based Technique for Order Preference by Similarity to Ideal Solution(TOPSIS) method for TMY generation. The entropy-based TOPSIS method is an objective method, in which the determination of weight and decision result does not involve any subjective preference but totally relies on the objective data set. This method can reflect the climate differences in different climate zones. The rationality of this method is verified by selecting five typical representative cities in China. The single meteorological parameter deviation analysis and building energy consumption simulation were used to evaluate the generated TMY. The results show that the TMY generated by the entropy-based TOPSIS method is closer to the long-term average. This method only considers monthly data, so the development of entropy-based TOPSIS is simpler and less time-consuming.

An efficient climate index for reflecting cooling energy consumption: Cooling degree days based on wet bulb temperature

AbstractCooling energy consumption of buildings is not only used for decreasing temperature, but for dehumidification. Therefore, cooling degree day (CDD) based on only temperature is insufficient for estimating the cooling energy consumption in buildings. In the present study, we aim to propose an efficient climate index (i.e., CDD based on wet bulb temperature [WBT], WCDD) based on the combination of cooling energy consumption in a building and joint probability of temperature and humidity. In addition, the adaptation of the new WCDD was verified in 14 cities of different climate zones in China. The results showed that CDD based on dry bulb temperature (DBT) (DCDD) can only explain 17%–60% of cooling energy consumption, whereas WCDD explaining 86%–97% of cooling energy consumption in the different climate zones. The optimal base WBTs are generally 17.74, 19.44, 21.04 and 22.56°C for the four climate zones, respectively. The present study reveals that WCDD by combining effects of temperature and humidity on cooling energy consumption can be much more efficiently used to estimate the cooling energy consumption compared with DCDD. More importantly, the WCDD is suitable for reflecting the cooling energy consumption for different climate zones. The collaborative changes of temperature and humidity under the conditions of climate change should be fully considered to take measures for decreasing the energy consumption for decreasing temperature and dehumidification.

Effects of short-term physiological and psychological adaptation on summer thermal comfort of outdoor exercising people in China

Internal migration from rural to urban areas is prevalent in China. Past studies demonstrated that thermal adaptation differed among people from various climate regions. However, the outdoor thermal comfort of exercising people with a diverse climatic background remains largely unexplored. This study examines the relationship between short-term physiological and psychological thermal adaptation and outdoor thermal comfort of exercising people from different climate zones in China. We recruited first-year students (n = 145) who engaged in outdoor training between 3 and September 14, 2018 in Guangzhou, China. Physiological parameters include heart rate (HR) from fitness trackers and skin temperature (Tskin) from iButtons. These students were surveyed regarding their thermal comfort and psychological state over the study period (n = 968). Physiological Equivalent Temperature (PET) was calculated from weather station data at the training sites. T-tests reveal differences in HR and thermal perception between local and non-local students, but not Tskin. Under similar PET conditions, non-local students reported a higher thermal sensation and greater thermal discomfort than local students during the first week of training. Logistic regression indicates that HR and metabolic rate predict the thermal sensation of non-local students, but not local students. Wind sensation, pleasantness level, fatigue, and perceived suitability for outdoor activities are significant predictors of local and non-local students' thermal comfort. Our research highlights both physiological and psychological factors (including emotion and fatigue) are necessary to understand acclimatized and non-acclimatized people's thermal perception. Addressing thermal discomfort at an early stage can prevent more severe heat-related illnesses.

Urban Thermal Characteristics of Local Climate Zones and Their Mitigation Measures across Cities in Different Climate Zones of China

Understanding the urban thermal environment is vital for improving urban planning and strategy development when mitigating urban heat islands. However, urban thermal characteristics of local climate zones (LCZ) are different within cities and most studies lack regional perspective. This study explored surface thermal performances of cities in three urban agglomerations (Jing-Jin-Ji, Yangtze River Delta and Pearl River Delta) in China using MODIS land surface temperature (LST). Besides that, the diurnal and seasonal LST variations of LCZs are also studied. Moreover, the optimal LCZs for better urban cooling are also investigated in this study. Although the thermal distributions of LCZs are different in China, there are still some similar features. Our four key findings were as follows. (1) LCZs in China are well classified, with average overall accuracy of 82% being higher than that in some previous studies. (2) The LST of mid-rise (LCZ 2, 5) is higher than that of high- and low-rise buildings (LCZ 1, 3, 4, 6); and compact buildings are warmer than open buildings (LCZ 1–3 > LST 4–6) in summer of China. That shows both mid-rise and compact buildings are not beneficial to cool urban. In addition, LST variations at daytime and in summer are more significant than nighttime and other seasons. (3) LST differences within LCZs are significant at p < 0.05, and are most significant in Jing-Jin-Ji (JJJ). The LST difference within built types (LCZ 1–10) is more significant than within natural types (LCZ A–G), showing that built types alteration will be more effective for thermal environmental improvement. (4) Under the current population and urban area, increasing greenness and water area in compact high-rise buildings are the most effective strategies for urban cooling in all three urban agglomerations, with the largest reduction in LST of 4.11 K in JJJ. These findings will provide support for thermal environment mitigation, urban planning and sustainable urban development.

Sensitivity analysis and prediction of shading effect of external Venetian blind for nearly zero-energy buildings in China

External Venetian blind shading (EVBS) is identified as an effective technology for reducing cooling demand in summer. Inappropriate design of the fenestration component may led to low energy efficiency, and there lacks simple methods to guide the application of EVBS in different climate zones of China, especially for nearly zero-energy buildings (NZEBs). This study explored sensitivity and regression analysis to identify and prioritize the most influencing parameters for cooling demand and shading performance, then used regression models to predict the shading performance. A new method of MC-AHP was proposed and used to quantify the sensitivity of the related factors, which was classified into three categories, on cooling demand and shading performance. The sensitivity analysis identified meteorological parameters are the most significant parameters affecting the cooling demand with a comprehensive weight of 0.82. Followed by building parameters with a weight of 0.11 and shading parameters with a weight of 0.07. The key influential sub-factors of these three types of parameters are outdoor temperature and solar radiation; shape factor (SF) and south window-to-wall ratio (SWWR); shading orientation (SO) and slat angle (SA), respectively.In addition, regression models between the shading performance and the key influential sub-factors were established for NZEBs with EVBS in different climate regions of China. And error analysis verified the accuracy of these models, which reveals that these regression models can effectively and accurately predict the shading performance. The regression analysis results indicate that WWR, SF, and SA are linearly related to the shading performance of EVBS, and the shading performance is always linearly related to SA regardless of how the shading orientation, WWR and SF change. This study can help architects determine the priority order of the optimal design of different building parameters in decision-making stages, then guide the efficient application of EVBS in new and retrofitted NZEBs.

A simulation-based method to predict the life cycle energy performance of residential buildings in different climate zones of China

This paper used a simulation-based method to predict the life cycle energy performance of residential buildings in different climate zones of China. After comparison, GISS-E2-R was selected as the general climate model (GCM) for generating future weather data, and 15 locations in different climate zones of China were involved. To predict the life cycle building performance, we created a Python procedure to generate future weather data files for every year from 2020 to 2099 for each location and performed simulations on a parametric simulation tool. According to the simulation results, heating energy is expected to decrease, and cooling energy is expected to increase in the future under the influence of climate change. The more climate change there is, the greater the heating energy and cooling energy of the building change. There are three trends in residential building energy demand. For the locations where heating energy dominates, there will be a significant decrease in total energy demand. For the locations in central China, the increase in cooling energy will offset part of the decrease in heating energy; therefore, there will be a relatively small drop in the total energy demand. For the locations where cooling energy dominates, the total energy demand is expected to rise. Finally, a simple sensitivity analysis was conducted to explore the impact of the passive design of the window-to-wall ratio (WWR), solar heat gain coefficient (SHGC), wall construction and roof construction on the life cycle energy demand under representative concentration pathway (RCP) 8.5 and 4.5.

The improvement and comparison of diffuse radiation models in different climatic zones of China

Diffuse radiation is vital for climatology, sustainable energy, agriculture and biological activities. It is often estimated based on some meteorological factors but seldom takes total cloud cover into consideration. In this study, cloud cover data are used to establish models, compared with other regular models for estimating diffuse radiation in different climatic zones of China during 1992–2015. The results showed that the performance of the new model based on sunshine fraction (n/N), clearness index (kt), total cloud cover (CI), air temperature (Ta), relative humidity (RH), wind speed and the day of the year outperformed other models and further improved the predictive accuracy. Generally, the kd models based on the single kt was generally more precise compared with single n/N-based or single CI-based models. And models on the basis of multiple factors performed better than the single factor-based model. Comparisons between these models indicated that neural network models (with the largest R and smallest RMSD values) provided better overall accuracy than other models. The parameter of CI as the co-factor can improve the prediction of diffuse radiation. The models developed and evaluated in this study can contribute to developing and utilizing solar energy in China, especially in areas without diffuse radiation records.

Investigation on the new design method of heat source for reducing the energy consumption in the shaft antifreeze system

In order to suppress the heat consumption for shaft antifreeze in coal mines, this study first analyzed the meteorological data required for shaft antifreeze in typical five cities (Harbin, Yulin, Hefei, Guiyang, and Nanning) located in different climate zones in China. The analysis results explain why some shaft heating measures must be taken in severely cold regions. So, in this study, Harbin is taken as the case city for research to show that the traditional heat load design methods have the problem of mismatching between the actual heat load and the designed heat load. Next, the annual temperature change analysis in Harbin reveals that the occurrence frequency of the extremely low temperature in a year is small and its continuation time is short. According to this finding, a new heat load design method is proposed based on the dual heat source usage. In this new method, the main heat source will be designed for flat-peak heat load compensation and the standby heat source will be designed for peak heat load compensation. The main heat source should be selected based on the outdoor calculated temperature for the shaft antifreeze system. The standby heat source should be selected based on the mean value between the average of the year-over-year lowest temperature and the outdoor design temperature for the adit system and on the average of the year-over-year lowest temperature for the vertical/inclined shaft system. The standby heat source accounts for 13% of the total heat load and the main heat source accounts for 87% of the total heat load in the adit system. On the other hand, the standby heat source accounts for 23% of the total heat load and the main heat source accounts for 77% of the total heat load in the vertical/inclined shaft system.

Projected Changes in Abrupt Shifts Between Dry and Wet Extremes Over China Through an Ensemble of Regional Climate Model Simulations

AbstractThe dry‐wet abrupt alternation (DWAA) event, which is defined as the phenomenon of dry (or wet) spells abruptly following wet (or dry) spells, magnifies the influence of individual wet and dry events. The dynamic evolution of DWAA events has not been studied for different climate zones of China that is particularly susceptible to dry and wet extremes. This study explores the future changes in the abrupt alternations between dry and wet extremes across 10 climate divisions of China, with a thorough assessment of dry and wet conditions using the Standardized Precipitation Evapotranspiration Index (SPEI). We take advantage of an ensemble of regional climate model simulations including the Providing Regional Climate Impacts for Studies (PRECIS) experiment and five CORDEX East Asia experiments to produce high‐resolution climate information for a baseline period of 1975–2004 and a future period of 2069–2098. Our findings disclose that a total of 70% of China's land area suffered from the DWAA events at least once during 1975–2004. The wet‐dry alternation event is projected to become more frequent in summer, and a prominent increase in the number of dry‐wet alternation events is expected to occur in spring over most parts of China. Moreover, an increasing number of DWAA events with intensified magnitude is projected to strike the North China Plain dominated by warm temperature and humid zone, which is the most densely populated region of the country and is also the largest agriculture production area. Our findings also reveal a strong positive correlation between DWAA and heavy rainfall. The 95th percentile rainfall event contributes most to the wet‐dry alternation event for most climate divisions of China.

Effect of ambient temperatures on category C notifiable infectious diarrhea in China: An analysis of national surveillance data

BackgroundMany studies have explored the association between meteorological factors and infectious diarrhea (ID) transmission but with inconsistent results, in particular the roles from temperatures. We aimed to explore the effects of temperatures on the transmission of category C ID, to identify its potential heterogeneity in different climate zones of China, and to provide scientific evidence to health authorities and local communities for necessary public health actions. MethodsDaily category C ID counts and meteorological variables were collected from 270 cities in China over the period of 2014–16. Distributed lag non-linear models (DLNMs) were applied in each city to obtain the city-specific temperature-disease associations, then a multivariate meta-analysis was implemented to pool the city-specific effects. Multivariate meta-regression was conducted to explore the potential effect modifiers. Attributable fraction was calculated for both low and high temperatures, defined as temperatures below the 5th percentile of temperature or above the 95th percentile of temperature. ResultsA total of 2,715,544 category C ID cases were reported during the study period. Overall, a M-shaped curve relationship was observed between temperature and category C ID, with a peak at the 81st percentile of temperatures (RR = 1.723, 95% CI: 1.579–1.881) compared to 50th percentile of temperatures. The pooled associations were generally stronger at high temperatures compared to low ambient temperatures, and the attributable fraction due to heat was higher than cold. Latitude was identified as a possible effect modifier. ConclusionsThe overall positive pooled associations between temperature and category C ID in China suggest the increasing temperature could bring about more category C infectious diarrhea cases, which warrants further public health measurements.

Adsorption experiment of water-soluble rare earth elements in atmospheric depositions and implications for source tracing in South China

The distribution patterns of rare earth elements (REEs) in fine-grained materials in various depositions were often found to be similar to those of the aeolian sediments deposited in the Loess Plateau in North China and the fine-grained materials were suggested to be derived from wind-blown dust. However, increasing evidence indicated that the REEs in the water-soluble portion of atmospheric depositions also displayed similar patterns to those of aeolian sediments. In this study, water-soluble REEs in three atmospheric depositions collected from different climatic zones in China were adsorbed with two adsorbents with distinct adsorption capacity, glass powder, and co-precipitated iron hydroxide. The results showed that the REEs adsorbed by the two adsorbents displayed patterns similar to those of the original atmospheric depositions. The typical characteristics of the REE patterns of atmospheric deposition can be well reproduced in the adsorbed REEs. The higher the REE concentrations in the atmospheric depositions, or the higher adsorption efficiency of the adsorbents, the better reproducibility of the REEs patterns. The results suggest that the REEs of the fine-grained materials in various sediments, which have a high adsorption capacity, especially those deposited in South China, may come from the water-soluble REEs in atmospheric deposition, and may not be appropriate tracers of wind-blown dust from North China.

Influence of acclimatization and short-term thermal history on outdoor thermal comfort in subtropical South China

Internal migration across different climate zones in China has increased as people seek better economic and education opportunities. Past indoor studies revealed the difference in thermal comfort and timescale of acclimatization of people from various climate zones. However, it is unclear whether the same results and mechanisms apply to transient outdoor conditions. To examine the thermal comfort of Chinese people with a diverse climatic background, we conducted an outdoor thermal comfort survey in Guangzhou and Zhuhai (n = 4267) in September 2018. We investigated the influence of long-term acclimatization and short-term thermal history on outdoor thermal comfort. When UTCI was 27.5–38.4 °C, the local respondents reported a lower thermal sensation than other climate zones. When relative humidity was 45–95%, there was a different humidity sensation and preference. Wind sensation was similar for different climate zones. One year of staying in Guangzhou/Zhuhai could diminish the difference in thermal and humidity sensation between climate zones. Furthermore, exposure environment and activity before the survey could modify this difference in outdoor thermal comfort between climate zones. Considering both long-term and short-term thermal history would improve outdoor thermal comfort forecast and meet the thermal comfort requirement of people with a diverse climatic background.

Evaluation of 18 models for calculating potential evapotranspiration in different climatic zones of China

The accurate calculation of potential evapotranspiration (PET) is a critical step in researching evapotranspiration, hydrology and many other fields. Numerous models have been developed to quantify PET from standard meteorological observations, and combination methods are usually considered the most physically reasonable. However, adequate observations of meteorological variables for combination methods are unavailable in many locations, making it necessary to select alternative PET models with fewer data requirements. Here, a set of 18 models including four aerodynamic methods, five temperature-based methods, six radiation-based methods, and three combination methods were evaluated using meteorological measurements from 789 stations in four climatic zones in China: the mountain plateau zone (MPZ), temperate monsoon zone (TMZ), temperate continental zone (TCZ), and subtropical monsoon zone (SMZ). The annual PET calculated in each of the four climatic zones showed large discrepancies among the 18 models, and the largest disparity nationwide was 2.95-fold. The combination models performed best for calculating PET in all four climatic zones, followed by the radiation-based models, and both categories outperformed the aerodynamic and temperature-based methods. The Rohwer model was the only recommended aerodynamic method, and the Romanenko model was the only recommended temperature-based method for calculating PET in China. The Turc model was marginally the best radiation-based model in the SMZ, TMZ and TCZ, and the Hargreaves model in the MPZ, but both should be applied with caution in cold months. The Penman model was the recommended combination method in all four zones. Further comparison of the best models from each category showed that the Rohwer model might overestimate PET in the TMZ and TCZ, and underestimate it in the MPZ and SMZ. The Romanenko model overestimated PET, and the Turc and Hargreaves models both underestimated PET in all four zones, especially in the MPZ. The empirical coefficients of the five recommended models were regional calibrated to meet the requirements of PET calculation in different climatic zones.

Suitability and feasibility study on the application of groundwater source heat pump (GWSHP) system in residential buildings for different climate zones in China

To alleviate the pressure of energy utilization of buildings, more attention was focused on the utilization of GWSHP (groundwater source heat pump) systems. However, there have been many debates on feasibility. This paper is to study the suitability and feasibility of GWSHP systems in different climate zones. A simulation model of a GWSHP system is established based on TRNSYS software in the severe cold climate zones A and B, cold climate zones, hot summer and cold winter climate zones, and the hot summer and warm winter climate zones. Simultaneously, the reliability and energy-saving benefits of GWSHP systems in typical residential buildings situated in different climate zones are deeply analyzed. Results reveal that the operating performance of GWSHP systems is considered as the best in the climate zones that need both heating and cooling loads for residential buildings. In contrast, the energy-saving benefits of the GWSHP system in typical residential buildings are deemed to be higher in the cold climate zones and severe cold climate zones. Overall, compared with the ASHP, the economy of the system is generally better based on economic analysis.

A ventilator that responds to outdoor conditions for ventilation and air filtration

Because of haze and fog in some countries, the outdoor air is polluted and cannot be directly drawn into rooms for ventilation. A ventilator with air filtration may be required. However, as outdoor particulate concentrations vary greatly with time, it is not ideal to operate high-efficiency particulate air (HEPA) filtration continually. This investigation proposed a ventilator with multiple modes of ventilation and air filtration. The ventilator could be switched between modes according to the outdoor and indoor air conditions. The ventilation rate and indoor particle concentrations in a test room equipped with the proposed ventilator were modelled by the EnergyPlus software program and validated with experimental data. The validated model was then used to evaluate indoor air quality and energy consumption in a hypothetical apartment located in each of five different climatic zones in China. The performance of the proposed ventilator was compared to that of a market-available outdoor air blower. It was found that to obtain the same acceptable indoor air quality, the necessary operating time for the proposed ventilator in the HEPA filtration mode was approximately 70% shorter than for the outdoor air blower, and the ventilator required approximately 30% less operating energy. In some southern cities in China, mechanically driven medium-efficiency filtration was sufficient to reduce the PM2.5 concentration to the acceptable level.

Daylight performance assessment of atrium skylight with integrated semi-transparent photovoltaic for different climate zones in China

The utilization of atriums in large space public buildings has significantly improved the internal lighting performance, but due to the harsh external environment, the application of large-scale skylights also brings higher heating or cooling energy consumption. Skylight Integrated Photovoltaic (SIPV) technology can not only use solar energy efficiently, but also has a significant shading effect, avoiding direct impact on the indoor light and thermal environment. At present, quite limited researches have studied the uncomfortable light environment of atrium caused by the application of semi-transparent photovoltaics in skylights. Therefore, it is very important to propose effective solutions to improve the daylight performance of these spaces or those with similar daylight climates.In this work, the indoor light environment has been systematically investigated through simulation employing DAYSIM tool. Both static and dynamic simulation analysis were carried out over the selected skylight glass to determine its appropriate area ratio of photovoltaic materials for representative Chinese cities. The optimal area ratio parameter range of thin film (TF) and crystalline silicon (C-Si) photovoltaic materials resulted in range of: 50–60% for both TF and C-Si in Xi'an represented area; 60–70% for TF, and 50–70% for C-Si in Beijing represented area; 50–60% for TF, and 60-70% for C-Si in Shanghai represented area; 50–60% for TF, and 50-70% for C-Si in Guangzhou represented area; 40–60% for TF, and 40-60% for C-Si in Harbin represented area; 30–50% for both TF and C-Si in Chongqing represented area. The optimal area ratio based design strategies of SIPV under various climatic conditions were then summarized.

Calculation of evapotranspiration in different climatic zones combining the long-term monitoring data with bootstrap method

Evapotranspiration (ET) is a central process in the climate system that plays a crucial role in the regional water cycle and climate regulation. However, estimating the effects of regional ET on the regional water cycle and climate regulation remains challenging due to the lack of quantitative methods and large-scale direct observational data. This study develops a new method to estimate evapotranspiration at regional scales using long-term monitoring data and the bootstrap resampling approach to calculate the ET unit area per year for China. This study applies the deviance information criterion as a goodness-of-fit index to select the most optimal formula for estimating regional ET for different climatic zones in China. The bootstrap resampling method was used to estimate parameter distribution in different climatic zones based on the outcome of 2000 trials. The results show that the predicted ET of adjacent climates overlaps with each other. The subtropical monsoonal climatic zone had the widest range of predicted ET (0–8000 mm/year), followed by the temperate and monsoonal climatic zones (0–1500 mm/year), mountain plateau climatic zone (0–1000 mm/year), and temperate continental climatic zone (0–500 mm/year). The probability distributions and isopleths of regionally predicted ET were also determined for China. The methods used in this study provide a promising tool to assess the effects of introducing large-scale forestation or restoration of trees on local water resources management.

Effects of watershed char and climate variables on annual runoff in different climatic zones in China

The complex interactions between climate and watershed characteristics lead to diverse annual runoff responses. Understanding the mechanism by which different climatic and watershed factors affect annual runoff is helpful in understanding the resulting changes in the hydrological process. In this study, the characteristics of 73 watersheds were analyzed. The basins were divided into three categories according to their climatic regions: temperate continental climate (n = 7); temperate monsoon climate(n = 36); and subtropical monsoon climate(n = 30). Correlation analysis, linear regression, and path analysis were used to quantify the effects of selected watershed characteristics and meteorological conditions on long-term runoff. Results showed that the average annual runoff coefficient was strongly correlated with basin area, showing a scale effect. The average annual runoff depth was strongly positively correlated with precipitation for the all watersheds. As the drought index (DI, the ratio of annual evaporation capacity to annual precipitation) increased, the annual runoff depth decreased logarithmically. The average annual rainfall and runoff depth of watersheds in the subtropical monsoon climate zone were significantly higher than those in other climatic zones, and there was no significant difference in potential evaporation between the temperate monsoon climate and subtropical monsoon climate zones. With increases in both the drought index (Ep/P) and moisture index (E/P), the vegetation distribution in the basin showed an increasing trend in farmland area and decreasing trend in forest area. Path analysis showed that rainfall had a positive effect on annual average runoff depth (ranging from 31 to 62%) while actual evapotranspiration had a negative impact (ranging from 17 to 47%). For all basins, a negative effect (13–25%) of basin area on runoff depth was observed, while forestland area had a positive effect (7–39%) on runoff depth. This study further quantified the effects of climatic and geographical factors on the long-term water balance in different climatic regions.

Retrofitting High-Rise Residential Building in Cold and Severe Cold Zones of China—A Deterministic Decision-Making Mechanism

This study aimed to develop a deterministic decision-making mechanism for finding the optimum set of retrofit solutions of existing high-rise residential buildings in two different climatic zones of China. The retrofit solutions were critically examined with different energy saving targets based on the local climatic conditions, building features, and retrofit costs in cold and severe cold zones comparatively. By making the extensive review and analyzing considerable statistics data and cost information, net present value (NPV) method was employed in the prototype building apartments to develop this deterministic model. The results demonstrated that the heating system is the most important factor in saving energy and obtaining the optimum revenue in these two regions. The highest optimal NPV can be obtained by achieving 60% energy saving in the cold zone, as energy saving is around 319 kWh/m2/year with the total retrofit costs of USD $3560, while it is 281 kWh/m2/year with the total retrofit costs of USD $3480 to achieve the 50% energy-saving target in the severe cold zone. Based on the analysis of energy savings and retrofit costs, the results can be effectively implemented for the purpose of creating sustainable retrofits in existing buildings, and the model can be adapted for selecting appropriate retrofit choices in other climatic zones.

Effect of Building Form on Energy Consumption of Academic Library Buildings in Different Climate Zones in China

This research focuses on the energy efficiency of academic library buildings with their shape in four major climate zones in China. According to their varieties in shapes and their representativeness in current constructions, eight hypothetical models of four types (point, slab, block, comb) are built based on the form of actual academic library buildings in recent years. The relationship between the building forms and building energy consumption is simulated and analysed with the software Design Builder. Results show that with the same construction area, different building forms can lead to variations in energy consumption in different climate zones. The slab-type is relatively energy-saving in most climate zones, while the block-type and E-shaped comb-type are more suitable for hot summer and warm winter zone. The building shape coefficient is an important parameter for reducing energy consumption in severe cold and cold zone, but the role of building depth is also sensitive. This information is dedicated to the architects at the early design stage of a project from the perspective of energy consumption.