Impact of climate change on residential building envelope cooling loads in subtropical climates

Future trends of cooling load due to heat gain through the building envelopes in the residential sector in subtropical Hong Kong under different emissions scenarios in the 21st century were investigated. Predicted monthly weather data from five general circulation models were gathered and analysed. An increasing trend of building envelope cooling load was observed. The average annual cooling load during the 2009-2100 period would be 6.1% and 9.8% more than that during 1979-2008 for low and medium forcing, respectively. If only the last 30 years (2071-2100) were considered, the percentage increase would be much larger at 12.3% and 21.6%. Four mitigation or energy conservation measures - raising the indoor temperature, thermal insulation, double glazing and tinted glass - were considered. Among them, raising the indoor temperature has the best mitigation potential because there is a growing awareness and recognition of adaptive thermal comfort and it can be readily applied to both existing and new buildings at no extra cost.     

大连市冬季民用住宅室内热湿环境的实测调查研究--建筑围护结构与室内热湿环境的关系

通过主观调查和实测相结合的方法,研究了大连地区冬季多层民用住宅室内热湿环境状况,并从建筑围护结构与室内热湿环境关系的角度,分析了在散热器间歇供暖条件下,建筑围护结构的保温性、蓄热性、气密性、楼层位置和朝向等因素对室内温湿度、居住者热湿感觉以及居住行为的影响。     

Optimal location and thickness of insulation layers for minimizing building energy consumption

This work aims to optimize the position and thickness of insulation layers in building external wall for climates in the coastal Mediterranean zone and in the inland plateau of Lebanon. A space and an air-conditioning system performance models are developed to predict the space and system loads and associated thermal comfort of occupants. A genetic algorithm is used for the optimization of the life cycle cost of the insulation based on energy load while including the productivity loss associated with thermal discomfort during transient periods. For continuous operation of building HVAC system, adding insulation reduces life cycle cost by 20% over current thermal code requirements. During intermittent operation, locating the insulation at the inner side of the walls results in 15% reduction in energy load compared to locating it on the outer wall. The optimum thickness varied between 3 cm and 5 cm depending on wall orientation climate season.     

某公共建筑外围护结构节能潜力分析

以夏热冬冷地区某酒店为例,对建筑全年的空调动态负荷及能耗进行了计算分析。给出了采用几种不同方案时建筑及房间的负荷和能耗计算结果,分析了夏热冬冷地区宾馆类公共建筑外围护结构的节能潜力。     

Implications of land disturbance on drinking water treatability in a changing climate: Demonstrating the need for “source water supply and protection” strategies

Forests form the critical source water areas for downstream drinking water supplies in many parts of the world, including the Rocky Mountain regions of North America. Large scale natural disturbances from wildfire and severe insect infestation are more likely because of warming climate and can significantly impact water quality downstream of forested headwaters regions. To investigate potential implications of changing climate and wildfire on drinking water treatment, the 2003 Lost Creek Wildfire in Alberta, Canada was studied. Four years of comprehensive hydrology and water quality data from seven watersheds were evaluated and synthesized to assess the implications of wildfire and post-fire intervention (salvage-logging) on downstream drinking water treatment. The 95th percentile turbidity and DOC remained low in streams draining unburned watersheds (5.1 NTU, 3.8 mg/L), even during periods of potential treatment challenge (e.g., stormflows, spring freshet); in contrast, they were elevated in streams draining burned (15.3 NTU, 4.6 mg/L) and salvage-logged (18.8 NTU, 9.9 mg/L) watersheds. Persistent increases in these parameters and observed increases in other contaminants such as nutrients, heavy metals, and chlorophyll-a in discharge from burned and salvage-logged watersheds present important economic and operational challenges for water treatment; most notably, a potential increased dependence on solids and DOC removal processes. Many traditional source water protection strategies would fail to adequately identify and evaluate many of the significant wildfire- and post-fire management-associated implications to drinking water “treatability”; accordingly, it is proposed that “source water supply and protection strategies” should be developed to consider a suppliers’ ability to provide adequate quantities of potable water to meet demand by addressing all aspects of drinking water “supply” (i.e., quantity, timing of availability, and quality) and their relationship to “treatability” in response to land disturbance.