1. Adaptability and Change: Low 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

2. 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

3. 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 change…not a sustainable sequence of events.
Introduction
Air conditioning
Adaptive comfort
Adaptive design
Comfort criteria
Conclusions

4. 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

5. 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
Air Con
Nat Vent

6. 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

7. 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

8. 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

9. 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

11. 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

12. 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

13. 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

14. 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

15. 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

16. Comfort criteria: Generally: 27oC <2% of occupied period.
CIBSE: 25oC <5% 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

17. 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

18. Introduction
Air conditioning
Adaptive comfort
Adaptive design
Comfort criteria
Conclusions

19. 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

20. 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

21. The End Introduction Air conditioning Adaptive comfort Adaptive design
Comfort criteria
Conclusions
The End