Koen Steemers

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Adaptability and ChangeLow energy design, urban
microclimate and climate change
Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions

• Koen Steemers
• Cambridge Architectural Research Limited
• and
• The Martin Centre for Architectural and Urban
  Studies
• Department of Architecture, University of
  Cambridge

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• The dilemma
•   Buildings cause 40-50 of emissions, creating
  pollution climate change.
• Buildings will be affected by the urban
  microclimate and climate change.
• 1. Reduce the energy consumption and emissions of
  buildings e.g. through passive design.
• 2. The urban climate and climate change can make
  the energy performance of buildings worse, or
  environmentally unacceptable to the occupants.

Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
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• Overview
• The urban environment and climate change has
  begun to enter the consciousness of the
  construction industry.
• The worry is that the response will be negative
  i.e. to increase the defensive capabilities of
  the building by throwing more energy use and
  systems at it.
• The result would be increased energy use,
  increased emissions and thus increased rate of
  climate changenot a sustainable sequence of
  events.

Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
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• The challenge
• 1. To show that increased energy use (e.g.
  conventional air conditioning) is not the
  solution to adapting to the urban microclimate or
  climate change.
• 2. To demonstrate how low energy design and
  comfort theory can address both mitigation and
  adaptation.

Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
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• Our senses have evolved to respond to a dynamic
  environment.
• Yet our buildings have become increasingly
  closely controlled, whilst consuming
  significantly greater amounts of energy.

Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
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• Implications of poor air con
• Reduced indoor air quality
• Sick building syndrome
• Increased absenteeism
• Reduced productivity
• Performance can be radically different from that
  predicted energy figures of twice those
  calculated are not rare in the first year of
  operation. Why?

Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
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• Performance discrepancies
• hasty commissioning
• lack of awareness of occupant interaction
• lack of post occupancy surveys
• rare feedback to the design team
• As a result, the construction industry tends to
  be slow to learn, change and adapt to new
  challenges.

Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
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• Mechanical control is in its infancy
• Passive design has centuries of tried and tested
  strategies
• Improved understanding of the interactions
  between building, environmental performance and
  occupant satisfaction is emerging.
• - form and fabric are an integral part of the
• environmental strategy
• - reducing the reliance on mechanical systems
• - enabling the occupant to adapt and interact
  with
• their own environment

Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
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• Low energy design and comfort
• Examples from extreme climates
• Adaptation of design and the occupants
• Relevant to challenges presented by the urban
  microclimate and climate change

Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
10

• Hot-arid Courtyard buildings
• Spaces (and locations within spaces) offering
  improved comfort conditions are consistently
  sought by occupants.

Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
Source Abu Merghani, The Martin Centre,
University of Cambridge
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• A range of spatial conditions internal rooms,
  intermediate verandas and external courtyards,
  with various thermal characteristics.

Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
Source Abu Merghani, The Martin Centre,
University of Cambridge
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• Other adaptive opportunities deploying openings
  and shading, changes to dress, activity level,
  posture, hot/cold drinks, sprinkling of courtyard
  and use of fans.
• The range and accumulation of adaptive
  opportunities available significantly improves
  comfort.

Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
Source Nick Baker, The Martin Centre, University
of Cambridge
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• The adaptive office
• Trend towards more flexible working patterns and
  office layouts, exemplified by the work of Frank
  Duffy and DEGW.
• Though not explicitly linked to comfort seeking,
  the notion of for example hot-desking offers
  that potential.
• Also, efficient space use means less floor space,
  which in turn could reduce the energy use per
  occupant.

Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
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• Adaptive building envelope
• Perceived comfort and productivity are associated
  with the opportunity to interact with the
  building envelope.
• e.g. views, operable windows and blinds.
• Small windows v. glazed facades
• temporary spatial adjustments to avoid sun
• more thermal mass
• reduced solar gains
• less need for shading (nb daylight and views)
• localised ventilation
• reduced costs, etc.

Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
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• Adaptive systems
• Avoid centralised BMS which leaves the occupants
  powerless.
• Use sensors and controls which enable local
  occupant interaction.
• Use systems that respond to occupant interaction
  with the building (e.g. opening a window turns
  off heat).
• The system should serve the occupant, combining
  robust climatic design with intelligent controls
  and components, to maximise adaptability.

Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
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• Comfort criteria
• Generally 27oC lt2 of occupied period.
• CIBSE 25oC lt5 of occupied period.
• A change from 27 to 25oC is a step back,
  particularly in the light of climate change.

Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
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• Applying the criteria
• Either criterion requires quite sophisticated
  dynamic thermal modeling.
• Despite such sophistication, no account is taken
  of adaptive opportunities a key determinant of
  comfort and energy use.
• Detailed simulation is only as good as the input
  data and assumptions, and reveals little about
  the robustness of a design.

Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
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Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
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• Conclusions
• Adaptation, through building design and occupant
  interaction (spatial, personal and systems
  control).
• Current criteria are insufficient to determine
  occupant comfort, complex to apply, and likely to
  result in the increased energy demand.
• EU standards should be designed so as not to
  limit diversity and regionalism.

Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
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• Conclusions

Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions
School, Como, Italy (Terragni)
Library, Viipuri, Finland (Aalto)
Source Peter Fisher, The Martin Centre,
University of Cambridge
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Introduction Air conditioning Adaptive
comfort Adaptive design Comfort
criteria Conclusions

• The End

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