《制冷专业英语》PPT课件.ppt

1,How does air conditioning become needed?,A case study of routes rationales and dynamics.,2,In the UK,air conditioning is becoming increasingly common in non-domestic buildings.From an energy and carbon perspective this is problematic.Identifying methods of preventing further reliance on air conditioning depends on understanding where and why it is being used.We draw on an analysis of the introduction of cooling in one complex case study site a hospital in the north of the UK to explore the processes of change involved.,ABSTRACT,3,3,We find that the spread of air conditioning is an outcome of repeated moments at which multiple,situated forms of need become established.We argue that the various entry points in processes of building design,refurbishment,reuse and thermal system repair are caught up in wider changes in the institutional context and working practices of the hospital.The use and reuse of internal space,increased reliance on heat emitting and heat sensitive technology and intense pressure to meet operational targets come together to create specific conjunctions in which air conditioning is seen to be necessary.,ABSTRACT,INTRODUCTION,Identifying methods of reducing and preventing further reliance on air conditioning depends on understanding the dynamic processes that are involved.,Explanations for the diffusion of technologies are many and varied,but often seek to model processes of change using a limited set of macro level variables.For air conditioning,such analyses have generally centered on the interrelation between climate and afford-ability.,This approach sustains the view that in hot climates further air conditioning is simply inevitable,disregarding potentially important differences of history,culture and context.However,whilst it is true that the cost of installing mechanical cooling has fallen,in the UK outdoor temperatures have not risen dramatically to somehow move it beyond a temperate climatic regime.,INTRODUCTION,Research beyond the US context has also demonstrated that the need for cooling is best understood not as a natural or inevitable requirement but as an outcome of specific situated processes.,Hitchings stresses the cultural differences and contextual dynamics shaping the manner in which urban people across different world regions have come to manage their daily relations with outdoor temperature.In this sense a universal global air conditioning regime has not become established,although as various authors note there are globalizing circulations of standards,norms and conventions that are pushing in that direction.,We focus on this hospital not because it is especially unusual,or because it is in any sense representative of hospitals in general,but because it allows us to understand in microcosm and within a diverse and multifunctional organization,the routes,circumstances and rationales through which air conditioning has over-time become progressively embedded in its functioning as a healthcare provider.,7,First,technologies,including air conditioners,do not exist or function alone.As is always the case,to some degree they are connected to and interdependent with other technologies and infrastructures.,Second,although buildings can appear to be rather static and obdurate,they are from other perspectives full of change and instability.,Third,suchbuilding projectdynamics,as suggested above,are to a significant degree subject to what goes on within them.Whilst buildings can be seen as the locus or site of ongoing practices of many different forms.,9,relatedOBSERVATIONS,First,technologies,including air conditioners,do not exist or function alone.As is always the case,to some degree they are connected to and interdependent with other technologies and infrastructures.,Second,although buildings can appear to be rather static and obdurate,they are from other perspectives full of change and instability,Third,suchbuilding projectdynamics,as suggested above,are to a significant degree subject to what goes on within them.Whilst buildings can be seen as the locus or site of ongoing practices of many different forms,Our case study is a hospital in the north of the UK that is part of the state-run National Health Service(NHS).The original hospital was built in the 1890s and its building profile was not changed significantly until the 1970s when a specialist unit with nearly a hundred new beds was established.Two more major buildings have since been added,one in the 1980s,the other in 1998.Many smaller non-medical buildings have been constructed in-between times,and there have been numerous rounds of refurbishment,extension and adaptation.The site,which consequently includes structures of very different architectural styles,exemplifies a century of developments in building design,and in materials and technologies.,The case study hospital,initial scoping interviews with the lead hospital energy and sustainability personnel,scrutiny of a variety of internal documentation(reports on energy and sustainability topics,minutes of committee meetings,Building Management System(BMS)log books,and databases compiled for maintenance and other purposes),guided tours of various parts of the hospital estate to talk in situ about buildings and air conditioning units,a set of in-depth semi-structured interviews with 10 members of the hospital staff,selected through snowballing from initial contacts and because of their involvement in installing,operating or using air conditioning across the site.,1.,2.,3.,4.,THE MEDICAL BLOCK,The heating,ventilation and air conditioning(HVAC)system integrated into the building design was required to provide mechanical ventilation to the whole block,following strict standards related to infection control,and in addition to provide cooling for the nurses stations and treatment rooms.Initially at least there was no intention of delivering cooling to anything other than these spaces far from external walls and to the windowless rooms at the core of the building.However,given that the system is in place,and that it is technically capable of cooling the wards as well,those operating the HVAC system through the BMS reported being under increasing pressure to use it for this purpose,regardless of the cost or the fact that such a strategy is in conflict with the hospitals ambition of reducing energy consumption and carbon emissions(which will return to later in the paper),12,THE PHARMACY,Our second example concerns one of the most recent installations of air conditioning.The pharmacy building,completed just four years before the time of the research,was described to us as“a metal clad insulated box with very few windows in it”.The pharmacy department is responsible for managing,sorting and issuing all the medication used in the hospital and the building includes a combination of storage areas and staff offices.It was designed and equipped with air handling(for all areas)and cooling just for the drug storage areas,the latter taking the form of five cassette cooling units.These are required to keep the storage areas at a temperature of 21C or below so as to ensure the integrity of the medicines they contain.In this case the need for cooling related to the needs not of people but of drugs,the proper storage of which was vital for the functioning of the hospital as a whole.,13,THE PHARMACY,For this case then we can see two routes in for air conditioning.Again it was part of the initial design,integral to how specific parts of the internal space would be made functional for their intended use,in this case the storage of drugs.Thermal standards for keeping drugs cool were embedded in the design which had to perform to achieve an acceptable degree of controllable thermal stability.The subsequent problem of overheating in other parts of the building galvanised a second,occupational health rationale for needing more cooling.Visible here are the systemic network of linkages between internal heat generation(from people and other technologies),insulation,ventilation and room temperature,such that once new internal spaces are filled and occupied their active use can disrupt assumptions made in initial building designs as to how this system will work.Air conditioning became a way of undertaking repair work to a system out of balance to the degree that it was deemed to threaten the health of its occupants.,14,According to the facilities managers the ICU has always been one of the hotter parts of the hospital.Even in the winter months the indoor temperature was usually well above that to be found else-where in the building.The facilities team was aware of this,and of staff complaints,but since the source of the heat was the substantial and ever increasing amount of(medically necessary)electronic equipment around each of the beds,and since the existing HVAC system was already working flat out,it seemed that there was little that could be done.,THE INTENSIVE CASE UNIT,15,Here we again see two routes in through the initial design and through repair work to an out of balance system.As with the pharmacy building,adding extra air conditioning represented the only possible way out of an otherwise impossible situation,this time occasioned by the damaging overheating not of people but of medical technology.Also in the background we can observe the pressure to reduce costs that were escalating across the NHS.More abstractly,we can see that over a longer time scale than in the pharmacy,the need for additional cooling arose as a result of the changing relation between the building,its cooling system,and the practices of intensive care.,THE INTENSIVE CASE UNIT,16,THANKS,