Evaluation of simplified ventilation system with direct air supply through the facade in a school in a cold climate

Many educational buildings in industrialised countries have poor indoor climate, according to today’s knowledge about the impact of indoor climate on well-being and productivity. Budget restrictions and practical limitations such as lack of space for central air handling units and ventilation ducts, have motivated the application of simplified ventilation systems in some schools, such as taking unconditioned supply air directly from the facade. One such school was recently evaluated in Norway.On cold days, thermal comfort in the classroom deteriorated due to cold downdraught from the supply outlet. In addition, moist and fertile conditions for microbiological growth were observed in the air supply ductwork. On the other hand the same pupils are more satisfied with the school and have less sick building syndrome (SBS) symptoms during winter than summer. An improved control strategy with a temperature-compensated CO₂ set-point for controlling the airflow is suggested. This could improve thermal comfort and reduce energy use without compromising perceived air quality (PAQ) during cold weather. Furthermore it could improve indoor air quality (IAQ) during warm weather with only a slight increase of energy use. Further evaluation of an improved solution is needed before such a ventilation concept can be recommended in cold climates.     

The distorted power of medical surgical masks for changing the human thermal psychology of indoor personnel in summer

The medical surgical mask (MSM) has been the essential protective equipment in people's daily work. The experimental purpose is to explore the effects of wearing MSM on human thermal sensation, thermal comfort, and breathing comfort in office buildings in summer. A total of 30 healthy college students were recruited for the testing. The experiment was carried out in a climate chamber, which can simulate the office buildings in summer. The experiment collects the subjects’ skin temperature, microclimate in the mask, and subjective votes, including thermal sensory votes (TSV), thermal comfort votes (TCV), and respiratory comfort votes (BCV). Experimental results show that wearing MSM has no significant effect on the skin temperature of the human body. The microclimate temperature inside the MSM reaches over 34℃, and the relative humidity reaches over 70%. The high-temperature and high-humidity microclimate put human beings in an uneven thermal environment, which leads to poor human tolerance to the thermal environment and becomes the main reason for destroying human thermal comfort. Wearing MSM has a significant impact on the subjective thermal sensation, thermal comfort, and breathing comfort of the human body, and the impact becomes more significant as the environmental temperature increases. Once the mask is taken off, the human body will enter an extremely comfortable environment, resulting in an excessively high vote value. The difference in voting values before and after removing the mask becomes larger with the environmental temperature. By fitting the voting results and perform data processing, it can be found that wearing MSM will reduce the neutral temperature by 1.5°C, and the environmental temperature with the optimal thermal comfort by 1.4°C, and as the temperature increases, the respiratory discomfort will become more and more intense. Regardless of whether wearing a MSM, the subjects preferred a slight warmer environment. In conclusion, with the increase of ambient temperature, wearing MSM can cause the human worse tolerance to the thermal environment, and this disturbance will become more and more intense.     

Air movement acceptability limits and thermal comfort in Brazil's hot humid climate zone

In hot humid climates, natural ventilation is an essential passive strategy in order to maintain thermal comfort inside buildings and it can be also used as an energy-conserving design strategy to reduce building cooling loads by removing heat stored in the buildings thermal mass. In this context, many previous studies have focused on thermal comfort and air velocity ranges. However, whether this air movement is desirable or not remains an open area. This paper aims to identify air movement acceptability levels inside naturally ventilated buildings in Brazil. Minimal air velocity values corresponding to 80% and 90% (V80 and V90) air movement acceptability inside these buildings. Field experiments were performed during hot and cool seasons when 2075 questionnaires were filled for the subjects while simultaneous microclimatic observations were made with laboratory precision. Main results indicated that the minimal air velocity required were at least 0.4 m/s for 26 °C reaching 0.9 m/s for operative temperatures up to 30 °C. Subjects are not only preferring more air speed but also demanding air velocities closer or higher than 0.8 m/s ASHRAE limit. This dispels the notion of draft in hot humid climates and reinforce the broader theory of alliesthesia and the physiological role of pleasure due to air movement increment.     

1st Environmental conference of Thessaly region, 8–10 September 2012, Hotel Skiathos Palace,Koukounaries, Skiathos Island,Greece

This study was conducted with the aim to assess the potential performance of a photovoltaic thermal mechanical ventilation heat recovery (PV/T MVHR) system. The device is currently considered for the application to the Z-en house project undertaken by Scottish homebuilder. The house’s whole energy demand was calibrated based on the UK Government’s standard assessment procedure for energy rating of dwellings, while the PV/T performance was estimated using an ‘EESLISM’ energy and environmental design simulation tool developed by Kogakuin University. This study concluded that PV generates heat, which makes the fresh air running under the PV roof 10–15?°C warmer than the outside temperature even during the Scottish winter and this warm air extracted from roof-integrated PV modules can be used to help reduce the domestic space-heating demand. Thus, the building-integrated PV/T MVHR system was considered as one of the effective means to assist the net zero energy operation of housing in cool and cold climates, whose dominant domestic energy comsumption derives from space heating.     

Thermal behavior and energy saving analysis of a flat with different energy efficiency measures in six climates

This article aims at studying the impact of many construction parameters of a flat on its energy performance and thermal comfort. The studied parameters are: the envelope thermal insulation, the orientation, the floor level, the ground coupling, the roof and the external walls absorption coefficient and the controlled mechanical ventilation. The TRNSYS based numerical study is performed in six different climates ranging from cold to desert one. The numerical model has been validated against experimental results obtained from summer and winter long term monitoring campaigns of the flat located in the Marrakech city, Morocco. The apartment’s heating and cooling loads as well as thermal discomfort indexes are calculated for the possible eleven configurations combining the studied parameters. The results show that high thermal insulation of the walls leads to an apparent summer overheating with an increase in the flat’s total thermal load by up to 18% in all the considered climates, except for the cold one. It was found that the walls’ light thermal insulation resulting from the cavity wall technique is sufficient to reach an acceptable level of thermal comfort thus preventing summer overheating. Similarly, thermal insulation of the slab-on-grade floor was found to perform an increase in thermal load for hot and moderate climates by at least 67%. The best combination of all the studied energy efficiency measures for each climate conditions was evaluated via comparison to a reference case that represents the actual apartment.     

HVAC and indoor thermal conditions in hospital operating rooms

Hospital operating rooms (ORs) require efficient HVAC installations to secure the highly demanding indoor environmental conditions for patients and medical personnel. This paper reviews published standards and guidelines on design, installation, commissioning, operation, and maintenance of HVAC installations in hospital ORs, indoor thermal conditions, and summarizes measured data from short monitoring of indoor thermal conditions along with audit results and main characteristics of 20 ORs in 10 major Hellenic hospitals. Measured indoor temperature ranged from 14 to 29 °C, and relative humidity from 13 to 80%. The number of air changes per hour ranged from 3.2 to 58 ACH. The commonly encountered problems include insufficient indoor air exchange, poor control on indoor thermal conditions, bad space ergonomics that influence the ventilation system operation, poor technical installations maintenance and understaffed technical departments. However, there are still opportunities for energy conservation, without sacrificing comfort, and overall quality of patient care or services.     

The impact of zoning regulations on thermal comfort in non-conditioned housing in hot,humid climates: findings from Dhaka,Bangladesh

In parts of the developing world where densities are high but the availability of air conditioning is limited, building massing and height regulations can influence interior comfort levels. Dhaka, Bangladesh, is characterized by high population densities, a lack of open spaces, and high poverty levels, combining to produce living conditions which are not only uncomfortable, but may lead to the spread of disease. A recent change in zoning regulations provides an opportunity to assess the success of building heights and setbacks in improving indoor thermal comfort conditions. We assess the impact on thermal comfort within Dhaka’s non-conditioned apartment buildings of four zoning schemes which differ in their specifications for setbacks, maximum buildable area, and building heights; but that maintains the current density. Computer simulation techniques model the buildings to test solar, daylight, and ventilation inside the central building to calculate resultant indoor temperature, mean radiant temperature, relative humidity and air velocity. Comparison between these values helps to determine which zoning schemes produce the most favorable thermal conditions. Findings suggest that zoning schemes that provide better solar protection and better natural ventilation are able to reduce indoor temperature and increase indoor air velocity over that provided by current zoning regulations. Recommendations for revising current zoning regulations are given along with general recommendations for how buildings in hot, humid climates can maximize passive cooling, encouraging energy savings and environmental sustainability.     

Development and visualization of time-based building energy performance metrics

ABSTRACT

In the face of climate change, and as building codes and standards evolve to promote increased building energy efficiency and reduced carbon footprints, it is also important to ensure that buildings, especially housing, can withstand prolonged power outages during extended periods of both extreme cold and hot weather to provide habitable shelter passively. This paper examines an approach for visualizing the impact of robust passive measures in multi-unit residential buildings by examining the ‘weakest links in the chain’ – the suites most susceptible to underperforming – in three climatic zones: Toronto and Vancouver, Canada; and Adana, Turkey. Two time-based and thermal comfort-related metrics are explored: thermal autonomy, a measure of what fraction of the time a building can deliver comfort without supplemental active systems; and passive survivability (also termed thermal resilience), a measure of the length of time a building remains habitable following the onset of a prolonged power outage during a period of extended extreme weather. A visualization of the results of parametric building energy simulations helps guide the selection of passive architectural parameters at the early stages of design to promote enhanced environmental performance and resilience.     

从城市绿地系统到城市生态系统的生态文明思想进化历程——以上海为例

从城市绿地系统到城市生态系统是当代生态文明思想在城市规划建设领域最重要的演进。伴随着当代中国生态文明思想的探索、发展到成熟阶段的演进,上海生态空间建设立足当下,克服土地资源极缺等主要困难,艰难起步、跨越发展、转型升级,从城市绿地系统到城市生态系统,探索出一种高效集约、统筹兼顾的韧性城市生态系统发展模式。展望中国两个百年目标及上海2035卓越全球城市目标,上海生态空间建设将以建设韧性生态之城为目标,努力营造更加"人民"、更加"生态"、更加"上海"的城市环境,让人民有更多获得感,为人民创造更加幸福的美好生活。     

Some significant environmental issues in high-rise residential building design in urban areas

Almost in all the major cities in Asian countries, residential buildings are characterized with high-rise and high density. Under this circumstance, achieving comfortable and healthy indoor environment with minimized energy consumption becomes a very challenging engineering and societal issue. While the wide use of air-conditioning helped to improve thermal comfort, health problems associated with poor indoor air qualities have appeared more frequently. The increased energy consumption is also a great concern in view of its impact on the energy economics of the region. Drawn from some of the onsite measurements and survey, and also the author’s personal observation, some of the key issues are discussed in this paper.     

玉林市可持续发展的生态足迹定量评价

依据生态足迹计算方法并运用生态服务价值的有关理论,对广西玉林市2004年生态足迹进行了定量计算,结果表明,玉林市2004年人均生态足迹为0.9417h㎡,可利用的人均生态承载力为0.2892h㎡,人均生态赤字为0.6525h㎡,反映了玉林市的生产、生活强度超过了生态系统的承载能力,玉林市生态系统处于过度开发利用的状态。通过分析玉林市人类活动对自然生态系统的压力和影响程度,为玉林市的生态建设和可持续发展战略提供科学依据。     

Courtyard design impact on indoor thermal comfort and utility costs for residential households: Comparative analysis and deep-learning predictive model

A courtyard is an architectural design element which is often known as microclimate modifiers and is responsible to increase the indoor occupant comfort in traditional architecture. The aim of this study is to conduct a parametric evaluation of courtyard design variants in a residential building of different climates with a focus on indoor thermal comfort and utility costs. A brute-force approach is applied to generate a wide range of design alternatives and the simulation workflow is conducted by Grasshopper together with the environmental plugins Ladybug and Honeybee. The main study objective is the evaluation of the occupant thermal comfort in an air-conditioned residential building, energy load, and cost analysis, derived from different design variables including courtyard geometry, window-to-wall ratio, envelope materials, heating, and cooling set-point dead-bands, and building geographical location. Furthermore, a Deep Learning model is developed using the inputs and outputs of the simulation and analysis to transform the outcomes into the algorithmic and tangible environment feasible for predictive applications. The results suggest that regarding the thermal loads, costs, and indoor thermal comfort index (PMV), there are high correlations between the outdoor weather variation and dead-band ranges, while in extreme climates such as Singapore, courtyard spaces might not be efficient enough as expected. Finally, the highly accurate deep learning model is also developed, delivering superior predictive capabilities for the thermal comfort and utility costs of the courtyard designs.     

The impact of building massing on net-zero achievability for office buildings

The simultaneous impact of massing on both energy consumption and renewable energy production potential is studied by taking the case of office buildings in Washington D.C. A Baseline design with a square footprint is compared with eleven massing alternatives: three rectangular parallelepiped designs with aspect ratios of respectively 2, 3, and 4, along the east-west orientation; three rectangular parallelepiped designs with aspect ratios of respectively 2, 3, and 4, along the north-south orientation; two H-shaped designs; one cross-shaped design; and two pyramidal buildings with wall slopes of respectively 86° and 83°. With differences between the best performing massing alternative and the worst performing massing alternative of more than 10% in terms of energy consumption, and more than 20% in terms of renewable energy production, massing is found to significantly impact both energy use and energy production. Consideration of both energy consumption and renewable energy production potential suggests that, for temperate climates such as Washington D.C., buildings with H-shaped footprints, buildings with crossshaped footprints, and buildings with high aspect ratio footprints are preferable when targeting net-zero energy status.     

地下建筑与中国气候

住所适应气候是生物界的普遍法则。中国气候的突出特点是大部分地区冬冷夏热，大陆性强。因而，我国建筑的热工能耗占总能耗的绝大部分，也成为解决我国建筑可持续发展问题的主要着手点。地下建筑在我国有着悠久的历史，它体形系数小、热稳定性好，非常适合我国气候条件的需要，且具有节能、节地、节材的特点。这种低技术手段在气候恶劣、经济欠发达的地区有着广阔的发展前景，应该成为我国实现建筑可持续发展战略的重要途径。     

钢筋混凝土结构的拉压杆模型设计方法及现状

钢筋混凝土结构抗剪计算一直是困扰工程界的一大难题，尤其是对于平截面假定不符合的区域(D区)，国内现有计算方法精度较差。国外近二三十年使用的拉压杆模型计算方法是D区最好的设计计算方法，其精度完全能满足工程应用的要求，能用于任何混凝土结构受任意荷载作用。本文简述了拉压杆模型方法的计算步骤及应加以注意的各方面，介绍了其发展的主要几个方向及其计算软件CAST。     

生态环境和地域气候与现代建筑设计

分析了现代社会面临的环境问题,并对现代建筑的消极气候观进行了介绍,简单探讨了气候、地域与建筑之间的关系,同时对生态技术应用于建筑设计中的两种表现类型进行了阐述,以针对不同的地域气候设计出合理的建筑作品。     

Use of continuous simulation model (COSIMAT) as a complementary tool to model sewer systems: a case study on the Paruck collector,Brussels, Belgium

Episodic Combined Sewer Overflow (CSO) discharges effectively control the ecological status of receiving water bodies. Hydrodynamic models like the Storm Water Management Model (SWMM) are often used to model the CSO events. However, such detailed models are computationally demanding especially when a long‐term simulation of a complex system is required. Considering this, we developed an alternative simple continuous simulation model (COSIMAT) using the SIMULINK? module in MATLAB? as a means of solving the issue of computational time associated with the detailed models. The COSIMAT model was tested against a detailed model set up on the SWMM. The Paruck collector – one of the major Collector of the Brussels’ sewer system was used as an example case. Results showed that the accuracy of the simplified COSIMAT model was comparable to that of the detailed hydrodynamic model (SWMM) with a significant reduction of computational time by a factor of 8. We believe such alternative approaches would be useful to replace a computationally demanding model component of an integrated modelling system of a complex sewer system.     

Thermal,emotional and perceptual evaluations of a park: Cross-cultural and environmental attitude comparisons

The main objective of the present study was to examine the influence of culture (Sweden vs. Japan) and environmental attitude (urban vs. open-air person) on participants’ thermal, emotional and perceptual assessments of a park, within the physiological equivalent temperature (PET) comfortable interval of 18–23 °C. It was predicted that persons sharing different cultures and environmental attitudes might psychologically differently evaluate a Swedish and a Japanese park despite similar thermal conditions. Consistent with this prediction, Japanese were shown to evaluate the weather as warmer and less good for out-door activity than did Swedes, although and according to the PET index participants in both cultures experienced similar comfortable thermal conditions. Japanese were also shown to evaluate the park as more pleasant and warmer place than did Swedes. However, the Japanese felt emotionally less pleasant at the site than did Swedes. An interaction between culture and environmental attitude indicated tentatively a difference in environmental attitude (urban vs. open-air person) between the two countries as regards the place-related wind sensitivity. All these findings are discussed in terms of culture and environmental attitude suggesting that thermal, emotional and perceptual assessments of a physical place may be intertwined with psychological and cultural processes, rather than fixed by general thermal indices developed in line with the physiological heat balance models.     

An investigation into thermal comfort in the summer season of Ghadames,Libya

This paper reviews the results from a field survey of thermal comfort within two types of buildings; old (traditional) and new (contemporary), in Ghadames oasis in Libya. The survey was undertaken in the summer seasons 1997 and 1998, which were typical of the hot–dry climate of North Africa. It shows how the 237 residents responded to the environmental conditions. Questionnaires were collected from the residents of 51 buildings: 24 old buildings that employ natural ventilation systems with courtyards and 27 new buildings that employ air-conditioning systems. In addition the environmental parameters were measured in 11 buildings (5 old, 6 new) representing 50 subjects, to calculate the predicted mean vote value of the subject using Fanger’s model as presented in ISO 7730 standard 1995. The survey has shown that the measurements of predicted mean vote (PMV) in new air-conditioned buildings provide satisfactory comfort conditions according to ISO 7730 and the occupants agree by indicating a satisfactory actual mean vote (AMV). The equivalent measurements and survey results in old traditional buildings indicated that although the PMV, based on measurements and ISO 7730, implied discomfort (hot), the occupants expressed their thermal satisfaction with the indoor comfort conditions. The field study also investigated occupants’ overall impression of the indoor thermal environments; the results suggest that people have an overall impression of higher standard of thermal comfort in old buildings than in new buildings.