Assessment of climate change impact on residential building heating and cooling energy requirement in Australia

This study investigated the potential impact of climate change on the heating and cooling (H/C) energy requirements of residential houses in five regional climates varying from cold to hot humid in Australia. Nine General Circulation Models (GCMs) under three carbon emission scenarios were applied to project the local climate. It was found that significant climate change impact on H/C energy requirements may occur within the lifespan of existing housing stock. The total H/C energy requirement of newly constructed 5 star houses is projected to vary significantly in the range of −26% to 101% by 2050 and −48% to 350% by 2100 given the A1B, A1FI and 550 ppm stabilisation emission scenarios, dependent on the existing regional climate. In terms of percentage change, houses in an H/C balanced temperate climate such as Sydney is found to be the most sensitive to climate change, potentially posing more pressures on the capacity of local energy supply. It was also found that energy efficient or high star rating houses may experience less absolute changes in energy requirement. However, they appear to experience higher percentage changes in the total H/C energy requirement. Especially in the regions with an H/C balanced temperate climate such as Sydney, the increase in the total H/C energy requirement is projected up to 120% and 530% for a 7 star house when the global temperature increases 2 °C and 5 °C respectively. The high sensitivity to global warming may need to be considered in the planning of future energy requirement for energy efficient buildings.     

Overcoming problems in house energy ratings in temperate climates: A proposed new rating framework

This paper first demonstrates that an efficient design for a house in conditioned operation mode differs from that for the same house in the free-running operation mode, and that this is a primary reason for the inability of current energy based rating schemes to adequately assess the performance of passive design in a temperate climate. We examine the Australian Nationwide House Energy Rating Scheme as an example of this problem. A new practical framework for a house rating scheme is then presented. In this proposed framework, the efficiency of a house design is evaluated with reference to its thermal performance in free-running mode, in addition to its projected energy loads in conditioned operation mode. The study uses simulation to evaluate the thermal performances of houses, and employs multiregression analysis to develop the framework. The reliability of proposed framework as compared to the current energy based rating scheme is demonstrated. By attributing more value to the performance of houses in the free-running than the conditioned operation, it is assumed that policy objectives for reducing energy demand for space heating and cooling in the residential building sector are more likely to be achieved.     

天津农村住宅围护结构调研及节能设计

针对天津农村住宅普遍存在的能耗高、室内舒适度差等问题,通过对农村住宅的体形系数、窗墙比、围护结构传热系数的分析,提出适合天津农村住宅的围护结构节能设计方案。建议采用天然材料和适宜的技术,以耗费最少的资源,实现农村住宅节能目标。     

Heat requirements and energy use in British houses

Housing data likely ranges of insulation levels are combined to give estimates of the heating requirements for conventional houses and small flats to be built in Britain in 1977–1987. After allowance for non-solar heat gains, requirements of 65–120 kWh/day for 4–6 person houses and of 8–47 kWh/day for small flats are predicted. The 65 kWh/day lower limit for houses will be improved on in the case of very well insulated houses using modified construction techniques.Data are collated showing average incidental heat gains from appliances, water heating, and other sources. The effects of these on annual heating energy use and on mean power requirements are assessed, and annual heating energy use per kW of design heat loss is calculated for a range of levels of incidental gains at three British locations; Pembroke, Croydon and Edinburgh. The typical solar contribution to this heating energy is also calculated.Mean-to-peak power variations are considered, showing that on average a heating system operates at 20–30% of the house design heat loss; this is the level at which energy use efficiency is most significant.The theoretical predictions of heating energy use are shown to give reasonable agreement with actual use as measured in field trials, despite the wide variability of the latter. The variation of total solar heating with orientation of a house with windows on two opposite sides is studied in the Appendix, showing a variation of ±15% in winter and ±6% in spring and summer for a particular house design.     

Evaluating the potential impact of global warming on the UAE residential buildings – A contribution to reduce the CO2 emissions

There is significant evidence that the world is warming. The International Panel of Climate Change stated that there would be a steady increase in the ambient temperature during the end of the 21st century. This increase will impact the built environment, particularly the requirements of energy used for air-conditioning buildings. This paper discusses issues related to the potential impact of global warming on air-conditioning energy use in the hot climate of the United Arab Emirates. Al-Ain city was chosen for this study. Simulation studies and energy analysis were employed to investigate the energy consumption of buildings and the most effective measures to cope with this impact under different climate scenarios. The paper focuses on residential buildings and concludes that global warming is likely to increase the energy used for cooling buildings by 23.5% if Al-Ain city warms by 5.9 °C. The net CO₂ emissions could increase at around 5.4% over the next few decades. The simulation results show that the energy design measures such as thermal insulation and thermal mass are important to cope with global warming, while window area and glazing system are beneficial and sensitive to climate change, whereas the shading devices are moderate as a building CO₂ emissions saver and insensitive to global warming.     

A two-component thermal model for a direct gain passive house with a heated basement

A model of a direct gain passive house with a heated basement was developed. This model predicts the room temperature and the heat requirement of houses as a function of meteorological variables and the design parameters. The key concept introduced to develop this model is that the basement heat loss can be divided into two components: one with an annual variation and one with a diurnal variation. The impact of these two components on the heat requirement of a house is analysed. The results are in good agreement with the experimental data as to the combined effects of the house heat loss rate, the thermal mass, and the solar gains. Of particular interest to house heating is the result that the basement walls in a passive house could contribute significantly to the thermal mass of the house.     

Urban Form and Thermal Efficiency: How the Design of Cities Influences the Urban Heat Island Effect

This article presents findings from a study on residential development patterns and urban heat island formation in the Atlanta, Georgia, metropolitan region. High-resolution thermal imagery collected by the National Aeronautical and Space Administration (NASA) is used in conjunction with parcel-level tax records to examine the interaction between the design of single-family residential parcels and the emission of radiant heat energy. Results from a path analysis illustrate that lower density patterns of residential development contribute more radiant heat energy to surface heat island formation than higher density development patterns within the Atlanta region. Compact moderate-to-high-density new construction and area-based tree ordinances are recommended as policy strategies for mitigating the effects of urban development on regional climate change.     

苏南农村住宅结构特点调研

以江苏省苏南农村地区为范围,对农村地区住宅的历史、现状及其发展进行了深入的调研。总结了该地区农村住宅的基本结构类型与分布状况,农村住宅的结构基本特点。相关的调研成果可对完善农村住宅结构的设计提供参考,为相关农村住宅设计软件的开发提供较为丰富、可靠的依据材料。     

The influence of automated window shutters on the design and performance of a passive solar house

Automatic control of windows shutters as a means for improving the thermal performance of passive houses is explored. In this model the enegy balances at the window surface form the basis for developing a control strategy for the shutters. The model predicts the heat requirements and the hours of overheating experienced in the house subject to temporal variations in radiation fluxes and air temperatures. The results show that automated window shutters can make positive contributions to the design and performance of passive solar houses. An examination into the model equations reveals that for a given house design the effectiveness of the shutters is dictated mainly by the rate as well as the severity of the changes in meteorological variables.     

居住密度与住宅形式关系的探讨与实践

论述了提高住宅居住密度的意义,同时评述了几种有效提高居住密度的中、低层住宅类型,从而对居住密度和住宅形式关系进行了探讨,以满足居住者生理、心理和社会生活等方面的需求。     

Comparison of physical performances of the ventilation systems in low-energy residential houses

The paper presents experimental results of the effect of ventilation systems in modern residential low-energy houses on thermal and humid conditions, heat consumption and perception of thermal comfort and air quality by their residents. Practical projects of modern residential houses with various ventilation systems which realize thermal, humid and psycho-physical comfort were worked out. To analyze the influence of ventilation systems on human comfort, results of questionnaires and comprehensive experimental measurements were taken into account. For measurements, 22 identical residential houses in Germany were chosen where 4 various ventilation systems were installed: gravitational (natural) ventilation, air heating system, mechanical ventilation with in- and out-leading air elements and a function of heat recovery and mechanical ventilation with single ventilators. The following parameters were measured in test units: relative air humidity, concentration of CO₂ in the air, air temperature, consumption of electricity, gas and heat, working time of the window opening, working time of the mechanical ventilation and number of residents. Advantages and disadvantages of ventilation systems were outlined. Experimental results were evaluated. Relationships between ventilation systems and thermal comfort were discussed by taking into account opinions of house residents.     

我国大中城市中小套型住宅舒适性研究

利用我国土地资源利用率、规范城市住宅用地,必然会对大中城市新建住宅的舒适性产生影响。文章从居住小区规划、住宅单元平面布局、户型套内功能空间设置、室内环境与物理性能,以及无障碍设计等5个方面,分析探讨了影响住宅舒适性的各个主要因素,提出了在90m^2以内控制性套型面积之内完善中小套型商品住房各种功能设置、提高居住舒适性的建议。     

Inherent variability of heat consumption in residential buildings

The paper concerns thermal energy consumption in residential buildings. Heat consumption data of 2280 buildings are compared. Special attention is given to compare heat consumption in identical buildings. Heat consumption variability analysis enables to evaluate inherent heat consumption for space heating dissipation which exists even if design and construction requirements are met. The attempt is made to find the numeral value of heat consumption dissipation caused by design and construction allowances. The analysis of multiflat panel sister-buildings annual heat consumption reveals that minimal value of maximal and minimal heat consumption ratio in identical panel buildings reaches 1.22 (95% confidence level). Data scatter testify erratic quality of construction works, in other words, maximal and minimal heat consumption ratio trend reflects quality of construction works as a whole. On the other hand awareness of inherent unavoidable heat consumption difference in similar houses may strengthen residents’ and policy makers’ confidence in energy saving tools and enhance thermal renovation of residential buildings.     

孝感地区新农村住宅建设的调查

通过对一些乡镇农村住宅进行的实地调查,文章分析了新农村住宅建设的现状,指出了当地农村住宅在建筑设计的合理性和实用性方面存在的一些问题,提出了相应的对策和建议。旨在改变农村建房观念,减少房屋安全隐患,充分发挥房屋的使用功能。     

双层铝板通风坡屋顶在湖南农村住宅节能改造中的应用

房屋建筑物顶部屋面全年受阳光热辐射,是建筑物受热最多也是最集中的部位。对于普通单层建筑,夏季屋面所得热量占建筑各面总热量的37%左右,而在冬季则能占到50%以上,导致屋顶面隔热能力的强弱直接影响了屋内的内热环境和能耗状况。湖南中北部农村的村民民房绝大部分使用小青瓦或机制瓦铺顶,下方形成阁楼与内屋相通,在没有采取隔热措施的情况下,夏季室温需要另外耗能降温。对此,以湖南农村住宅为实例,对双层铝板通风坡屋面的隔热改造技术在农村建筑节能工程中的应用进行了阐述分析。     

Micro-generation technology assessment for housing technology

Micro-generation is defined as a notion of simultaneous generation of both heat and power in an individual dwelling. It offers an elegant and economically viable way to meet the residential power/thermal loads and Kyoto targets by demonstrating superior environmental performance with high efficiency and low harmful greenhouse gas emissions. However, before introducing micro-generation systems in large quantities a number of issues should be resolved in terms of system integration, interconnect, reliability and safety.Two demonstration houses were built at the Canadian Centre for Housing Technology that have the capability of assessing different energy and building technologies under real-life conditions. A project was initiated involving a consortia of Canadian electric and gas utilities, Canadian Government agencies and Canadian fuel cell manufacturers to modify one of two existing research houses and to integrate a prototype micro-generation unit in it that would provide electricity and heat to the house, and supply surplus electricity back to the grid. The key research objectives were assessment of building integration, micro-generation system design issues and system performance characteristics. A Stirling engine micro-generation unit, fuelled by natural gas, was used for this demonstration. The unit had an electrical output of 736 W_e and a thermal output of 6.5 kW_th. The Stirling engine was connected in parallel to the grid and the residual heat from the engine was utilized through a specifically designed heat utilization module.The paper discusses the micro-generation system performance in two different setups and scenarios that were tested over the 2003 winter/spring seasons. Data showed that the micro-generation unit was able to satisfy all of the space and water heating loads to the house during the testing period. The unit provided a considerable percentage of the house’s electrical requirement, and even exported, in a few instances, some electricity back to the grid.     

日本集合住宅设计与生产工业化——住宅高附加值生产与多样化对应

钢筋混凝土预制板住宅是日本住宅生产工业化技术的代表。但是现有高附加值的生产方式很难有效地满足住户多样性的设计要求,生产变更的发生直接影响到住宅生产的发展。通过对日本代表性PC住宅生产的调查与研究,阐明了PC住宅高附加值生产及生产变更发生的原因,特别是对排除电气预埋部件有效地提高住宅生产性,满足住户多样性设计要求的课题有了明确的认识。     

北京市住宅室内空间改造案例研究

20世纪90年代建造的老旧住宅正在逐步进入功能老化期,对其室内空间进行改造和更新成为迫切需要。通过对北京市三个建造于20世纪90年代的普通住宅进行入户测量和访谈,该文在描述普通住宅室内空间改造过程的基础上,分析住宅室内空间改造的影响因素,评价其改造后的使用效果,总结其改造的方法和材料,以了解老旧住宅室内空间的特点和住户在改造中关注的主要问题并提出应对措施,对老旧住宅室内空间改造提供帮助,使其经过合理改造能够更好地适应家庭生命周期的变化和现代生活的进步,同时使新住宅关于室内灵活可变空间的设计有所借鉴。     

Natural ventilation design for houses in Thailand

This paper explores the potential of using natural ventilation as a passive cooling system for new house designs in Thailand. The characteristics of past and present Thai houses are analyzed in terms of climate, culture, and technology. Based on the thermal comfort requirements for the Thai people and the climate conditions in Bangkok, the study found that it is possible to use natural ventilation to create a thermally comfortable indoor environment in houses in a Bangkok suburb during 20% of the year. This study also develops comprehensive design guidelines for natural ventilation at both the site planning and individual house levels by using computational fluid dynamics.     

Thermal analysis of the architecture of old and new houses at Ghadames

The study suggests improvements in the design of new houses to conserve energy and enhance indoor thermal comfort. Summer temperature records show that a new house has an average indoor temperature of 35°C with the ambient average 31°C. The traditional house in the old city recorded 28°C for the same period. Winter temperatures in both types of houses were similar (12°C) when not occupied. Architectural features of the two houses were compared to identify those responsible for difference in the thermal performance. Larger exposed surface and window areas, higher overall heat transfer coefficient and weaker thermal coupling with the ground for the new houses seems to contribute to their inferior thermal performance.