建筑学毕业设计文献翻译（可编辑） .doc

建筑学毕业设计文献翻译 大学建筑工程学院2012年5月外籍文献ventilation of sustainable schoolsbetter than traditional schoolsw zeiler g boxemsummaryduring the last decades in the united kingdom several educational buildings were built with a strong environmental ethos real icons of a new generation of low-energy sustainable buildings in some of the buildings post occupancy evaluations were held and buildings performance was revealed also in the netherlands during the last years several new concepts were developed for sustainable schools this is an interesting topic as many of those schools had problems concerning energy efficiency indoor air quality and thermal comfort in the case of sustainable schools much effort went into the design process of the schools to try to find better solutions to face the problems of the traditional designs this resulted in different solution concepts which raises the question which are better school concepts from literature three evaluations from the uk and one overview of 5 sustainable educational buildings from the netherlands are given which show that sustainable educational buildings are not always without flaws in the paper two of the first dutch sustainable elementary schools are compared with 9 more traditional schools of the netherlands to conclude whether the sustainable schools perform better than traditional schoolsintroductionpresently sustainability becomes a necessity as effects of global warming become more clearly it is important to start early with the educational aspects of the necessary change in behavior and thinking sustainable schools could play an important role the whole concept of a sustainable school building is based on principles of sustainable development which deal with the limited availability of natural resources the interdependence with nature the fundamentals aspects of interdependence with nature the fundamentals aspects of production and consumption and the issue of equity within between and among generations 1as the icon of a new generation of sustainable educational buildings which was completed in late 1993 the queens building at de montfort university leicester gained a reputation with its startling architecture in particular the distinctive ventilation chimneys 2 see figure 1 the queens building was seen as the first in a new generation of lowenergy naturally ventilated sustainable buildings architect short ford associates worked on the building design alongside environmental engineer fordham llp cambridge rchitectural research on the stack-effect chimneys and bristol university on the physics of the airflow the 10000 m2 building is l-shaped containing a complex arrangement of laboratories classrooms and offices the structure is almost exclusively naturally ventilated 2a detailed picture of the buildings performance was revealed in 1996 when a post-occupancy evaluation was carried out as part of the probe post-occupancy review of buildings and their engineering project the assessment revealed a number of key shortcomings unresolved defects meant that for the first two years the building operated with problems in critical mechanical and control systems 2 probe researchers found that the buildings design seemed to be effective at maintaining a comfortable environmentalthough the survey of its occupants conducted by building use studies bus showed dissatisfaction with high summertime temperatures and stuffiness in both winter and summer months 2a revisit during early august 2006 revealed that some parts of the building have changed dramatically since the probe assessment while others are much as they were when it took place during the revisit an occupant survey was held and forty-five questionnaires were completed compared with 75 in 1996 in general terms satisfaction with temperatures in both summer and winter is the same although occupants perceive the air in winter to be better levels of satisfaction are very dependent on location for example the relatively high satisfaction rate for the refurbished offices is not matched by users in the new laboratories in 1995 hampshire county council architect sir colin stansfield-smith designed a imaginative low energy educational building for portsmouth university employing several environmental systems and ventilation strategies designed to liver comfortable conditions and be of didactic value to the students externally the building is a white-painted rendered fortress 3 see figure 2 internally it is light and bright with white painted walls windows and steelwork complete with simple but good finishes five stair towers around the buildings periphery act as natural ventilation air exhaust paths for the classrooms studios and staff offices with the exception of those on the top floor the portland building was also investigated by the probe team 3questionnaires by 46 staff rated the building well as an all-rounder coming just within the top 20 of the reference dataset though people were happier with the aesthetics than with comfort or functionality 3 there was however a good overall wintertime comfort even though the building was judged to be hotter stiller and stuffier than average summer comfort was judged average overall but with a wide range of response and some people stated that is was significantly hot the building has good perceived air quality in both winter and summer besides some local problems 3 during the summer of 1997 an analysis of monitored air and slab temperatures was done by kolokotroni et al for the purpose of designing naturally ventilated educational building from their analysis they concluded that natural ventilation coupled with exposed thermal mass can reduce the effect of external hot weather and establish comfortable conditions within the building it has also shown that if this moderating effect of thermal mass and natural ventilation is not controlled unfavourable internal conditions can be established under certain external weather in particular cold spells during the summer 4 since occupation the major changes have been a general increase in the use of computers leading to occupancy and equipment densities and heat gain and ventilation requirements beyond design expectations in some rooms lack of flexibility to cope with increased capacity is a weak point of the sustainable design conceptin the study of sharples et al 2007 norfolk community primary school in sheffield uk see figure 3 built in 2005 with many sustainable features was subjected to a post occupancy evaluation poe that involved both a social analysis and environmental monitoring one of the key questions of the study was did the school performing better environmentally than a standard school 5the uk governments department for education and skills dfes building bulletin bb101 ventilation of school buildings recommends that for teaching and learning spaces between the start and finish of teaching on any day the average concentration of carbon dioxide should not exceed 1500 parts per million ppm in addition bb101 recommends that for any occupied time including teaching the occupants should be able to lower the concentration of carbon dioxide to 1000 ppm figure 4 shows the mean co2 levels for the teaching and week-end periods the dashed lines show the 1500 ppm and 1000 ppm levels suggested in bb101figure 5 presents the indoor and outdoor air temperatures over a ten day winter period from friday 17 february to monday 27 february 2006 the dashed line in figure 5 is the internal air temperature of 180c recommended in the school premises regulations and quoted in building bulletin 87 5as can be seen from these three british examples sustainable buildings are not flawless so what is the situation in the netherlands unfortunately there were only a few case studies done most important one was the evaluation of the first pilot projects of sustainable educational buildings to show what is possible in practice with sustainable building design the dutch government sudsidized several pilot projects from the 17 utility buildings there were 5 educational buildings van hall institute hogeschool limburg educatorium peuterpalet and scholencomplex rijkerswoerd the performance of these schools were monitored during a couple of years and presented in a overall study 6 the results are given in figure 6 if we realize that normally the percentage of dissatisfied is between 10 to 20 we see clearly that some of the sustainable schools perform on some aspects worst than traditional schoolsin the netherlands with respect to sustainable educational building the main focus has been on energy saving leading to a reduction of 30 compared to the dutch building regulations this led to the application of hybrid ventilation natural supply and mechanical exhaust ventilation within the annex 35 hybrid ventilation in new and retrofitted buildings an international research project initiated by the iea implementing agreement energy conservation in buildings and community systems the scope was to obtain better knowledge of the use of hybrid ventilation technologies 7 to avoid cross ventilation each classroom has been equipped with a local ventilation system that consists of 2 electronically controlled inlet grills in the facade and a fan supported natural exhaust chimney co2 sensors and temperature sensors automatically control the ventilation system to meet the energy performance requirements the building has a high level of thermal insulation u-values the overall heat transfer coefficient of opaque parts 031 wm2k 176 btuft2 f h u-value of windows 18 wm2k 1021 btuft2 f h good air tightness and energy efficient building services high efficiency natural gas-boiler for heating and domestic hot water and high frequency lighting the extra 30 energy savings above the mandatory level of the building regulations are provided by the hybrid ventilation system 15 and daylight sensors and a central sweep switch on the lighting system 15 methodologytwo sustainable designed schools were analyzed and the results compared with other more traditional schools to investigate the results of the sustainable schools measurements were done concerning thermal comfort and indoor air quality during a week different measurements in schools were undertaken to be able to define the quality of indoor air quality and thermal comfort of the two sustainable schools one school is the first sustainable elementary school of the netherlands 1 the other school was part of the iea inter-national energy agency annex 35 hybrid ventilation project 7 so they are both relevant examples of sustainable designed schools as suchindoor air quality iaq at schools is of special concern since children are extremely sensitive to results of poor air quality iaq in schools must reach the basic requirements and should be considered as a high priority because 8 1 children more sensitive as they still developing physically and more likely to suffer from indoor pollutants these growth processes are delicate and vulnerable to disruption 2 children are less well able than adults to metabolise and excrete most environmental toxins 3 children are relatively more heavily exposed to environmental toxins as they breathe higher volumes of air relative to their body weights good air quality in classrooms supports childrens learning ability poor iaq in schools influences the performance and attendance of students primarily through health effects from indoor pollutants 9 literature on relationships 10 between indoor air and environmental quality ieq in class rooms and students health and academic performance has been reviewed 11 carbon dioxide concentrations are often used as a substitute of the rate of outside supply air per occupant 12 iaq in schools is primarily evaluated by co2-concentrations ashrae standard 62-1999 recommends an indoor co2-concentration of less than 700 ppm above the outdoor concentration 1200 ppm to satisfy comfort criteria with respect to human bio ffluents dutch schools have to meet the dutch building code bouwbesluit which recommends a level of 1000 ppm co2-concentration with a imum of 1200 ppmschoolsbetween january 29th till march 31st 2004 measurements were conducted in 5 selected schools the measurements were conducted in alphabetical order from school a1 to e1 see table 1 13between january 13th till february 22st 2005 the second series of long-term measurements were conducted in 6 new selected schools see table 2 schools b2 and f2 are the sustainable designs 14measurementsone classroom in each school building was selected for the measurements in the heating season during 1 week which include long-term measurements of air temperature radiant temperature relative humidity and air velocity equipment specifications used for those long-term measurements are shown in table 3questionnairesin all schools questionnaires were given to the teachers to get an impression of the satisfaction of the users with regard to indoor air quality and thermal comfort the questionnaires had questions about environmental perception and application of the system for the winter situation comprised perceived thermal comfort perception of indoor air quality etc13the users have been asked to rate different aspects of the comfort distinction is made between summer and winter users opinion is the central point of this research the questionnaire used is based on the validated list which has been developed in the health optimisation protocol for energy fficient buildings research 15 the questions are based on a unipolar scale and should be interpreted as 1 very good 5 unacceptable table 4 gives the complete overview of the completed questionnaires from the different schools as the research was focused on primary schools we were not able to ask the pupils questions and could only let the teachers fill in the questionnairesresultsresults measurements t is important to look at the co2-concentrations as a indicator for the indoor quality within the classrooms the average level was determined for which during 50 of the time of use his level would not be succeeded co2-pm50 also the level was determined for which 95 of the time of use this would not be succeeded co2 pm95 these values are based on the actual measurements and the actual occupations of the classrooms also the co2-concentrations were calculated based on the measurements and the additional increase of the co2 ncentrations based on the design conditions of an occupation of 32 pupils and one teacher in the classroom the so called co2-pm 95 33p value see table 5 because of it significant the co2-pm 95 33p value is presented in figure 7 separately also the effective ventilation rate within the classroom is determined by using the rise of co2-concentrations results questionnairesthe focus of this paper is on the iaq so the focus was on these aspects and the teachers were asked how they perceived the humidity of the air the freshness odors and overall satisfaction about the indoor air quality see figures 8 9 10 and 11 comparison resultsthe following table represents the results of the measurements and questionnaires for the important aspects the comparison is made between the average of the traditional school of series 1 and 2 compared to the specific sustainable design for school b2 and f2 see table 6 to sum up all the results overviews are presented of all the calculated mean pm 95 33 co2 concentration based on the measurements during the winter period of all the projects and the results of questionnaires about aspects of perceived iaq in winter situationas can be seen the sustainable schools do not perform better on all aspects remarkable is the difference in quality of iaq perceived by the teachers of school b2 and measured through the pm 95 33 co2 although the measured improvement is more than 20 related to the co2 concentration the perceived overall satisfaction in school b2 is worst by 21 in school f2 the perceived overall iaq satisfaction is in line with the expectation based on the improved co2 concentration withan 29 better results compared to the average of traditional schoolsthe perceived feeling of humidity by the teachers of thesustainable schools b2 and f2 is worst compared to traditionalschools this can be explained as the ventilation is controlledby co2 and therefore related to the hours of use besides these hours ventilation is kept on a much lower level this lower ventilation rate is probably not sufficient enough to dispose all moisture within the classroom after the pupils have left the classroom also the aspect perceived of odor indicates that the overall ventilation is not enough to dispose of the odor of the pupils after the lessons and maybe also odor of emitting building materials in the classroom with as result that odor is left within the classroomdiscussionin the past in the netherlands different investigations on indoor air quality were conducted and co2 levels measured in 1992 the local health department ggd in west-brabant researched indoor air quality in secondary education buildings measurements of co2 levels were done and levels up to 4800 ppm were detected 16 in 1997 iaq measurements were done at 4 primary schools in the region of east noordbrabant peak levels of 3500 ppm were detected 17 the results of our measurements are well within the range of the earlier dutch resultsalthough the number of questionnaires completed at each school is far too low to have statistical significance average of all schools compared to the two sustainable designed schools still has relevancean important aspect when comparing sustainable schools with traditional schools is the energy variable comparing the energy variable makes it possible to understand the possible trade-offs between