Associate Professor Richard de Dear, PhD
Head, Department of Physical Geography,
Macquarie University,
Sydney, Australia.
A/Prof de Dear is research active across a diverse range of topics in applied climatology and meteorology, but most of his research attention over the last 25 years has been focussed on interactions between buildings, their occupants, and their climatic environment. This topic has been promoted to international prominence in recent years because of three basic facts; a) climates are changing (IPCC IPCC WG I), b) built environments are responsible for about 25% of the greenhouse gas emissions causing climatic change (IPCC WG III), and c) the provision of indoor thermal comfort represents one of the largest energy end-uses within the buildings sector. Connecting these three observations together makes it clear that building occupant comfort will figure prominently in greenhouse mitigation strategies and the broader drive towards sustainable built environments in coming decades.
The overarching theme throughout de Dear’s research career is that occupants represent the crucial link between climates prevailing outside and inside their built environments. Building on the pioneering work of others such as Humphreys, Auliciems, and Nicol in the 1980s, de Dear and Gail Brager (UC Berkeley) have firmly established that building occupants’ adaptations to the broader outdoor climatic milieu have a strong bearing on their expectations of indoor climates. People adapt to outdoor climate through complex and interconnected physiological, behavioural and psychological mechanisms, and these adaptations, when acknowledged and understood by designers and engineers, can bring about major energy savings in buildings. De Dear and Bragers’ work is now widely recognised as “the ASHRAE adaptive model of thermal comfort” and it has been distilled into a algorithm that predicts the range of temperatures that building occupants will find acceptable, based on statistical summaries of the outdoor climate to which they have become adapted. Adaptive temperature ranges provide a useful tool for architects and engineers during the design stages of a building, but they are also relevant to facilities managers or energy auditors who want to assess the performance of a building post-occupancy.
The de Dear and Brager adaptive model of thermal comfort had its most significant international impact in 2004 when it was incorporated into the American Society of Heating, Refrigerating and Air-Conditioning Engineers’ (ASHRAE) influential comfort standard known as ANSI/ASHRAE Standard 55: Indoor Environmental Conditions for Human Occupancy. This new American standard includes an entire section dealing with the implementation of de Dear and Bragers’ adaptive comfort model in naturally ventilated buildings. The Netherlands’ new Adaptive Temperature Guideline for use in building energy performance assessments is also based upon the de Dear and Brager adaptive comfort model.
The adaptive model of thermal comfort has earned de Dear numerous Australian and international keynote invitations in recent years, including:
- The 18th International Congress of Biometeorology (ICB’08), Tokyo, Japan, 22-26 September 2008.
- The 6th International Indoor Air Quality, Ventilation and Energy Conservation in Buildings Conference (IAQVEC ’07), October 2007, Sendai Japan.
- Subtropical Cities 2006 , Brisbane, 26-30 September 2006
- Healthy Buildings 2006 , Lisbon Portugal, 4-8 June 2006.
- The 17th International Congress of Biometeorology (ICB’05) , Garmisch-Partenkirchen, Germany, 5-9 September 2005.
- AIRAH Conference, Systems Design Approach for Air Conditioning . Sydney 17-18 March 2005.
- Symposium in Honour of Professor Ole Fanger’s Retirement from the Technical University of Denmark , Lyngby, Denmark, August 2004.
- The 10th International Conference on Environmental Ergonomics , Fukuoka Japan, 23-28 September 2002.
de Dear’s list of research publications can be found here. According to Google Scholar bibliometric tool these publications have received 856 citations (as at 16 August 2007).
Perhaps more important than citations in the research literature are impacts on architectural and engineering practice; i.e. applications of the model during the design and engineering of buildings. There are numerous Australian and international examples, but perhaps the most famous to date is the San Francisco Federal Building, due for completion in 2007. When completed this 60,000 m 2 flagship green office building will house five different agencies of the USA Federal Government. he building deploys a number of innovative technologies, including an integrated custom window wall, thermal mass storage, and active sun shading devices to regulate internal thermal environmental conditions within the adaptive model’s seasonally adjusted comfort ranges. The interested reader is referred to this design documentation to learn more about how the comfort model was used to calculate indoor design temperatures for the San Francisco Federal Building.