The Effect of Facades on Outdoor
Microclimate
Jonathan Fox PhD Candidate Faculty of Built Environment UNSW Australia
ACCARNSI Early Career Researcher Forum Canberra 15-17 February 2016
Acknowledgments
Research funding provided by CRC for Low Carbon Living under
Program 2 – Low Carbon Precincts, Research Project RP2005 – Urban Micro Climates: Comparative study of major contributors to the Urban Heat Island
effect in three Australian cities: Sydney, Melbourne, Adelaide Relationship to RP2005 Institutions
Research Context –
2050: 66% 6.3 billion 2014: 54% 3.9 billion United Na*ons, Department of Economic and Social Affairs (UNDESA), Popula*on Division (2014). World Urbaniza-on Prospects: The 2014 Revision, Highlights Research Context –
2887
heatwave deaths in
Australian cities 1890 - 2013
89% 93%
5 million
2050: 66% 6.3 billion 2014: 54% 3.9 billion current and projected 2050 Australian
urban population. Projected Sydney
population in April 2016
0.5m 1.9m
18% 19%
current and projected 2055 Australian
population over 85yo; projected % over
65yo and % 65yo living in cities
Quan*fying the impact of climate change on extreme heat in Australia by Will Steffen (Climate Council of Australia). 2015 Research Context – Cities and Heat
o  Climate change amplifies the Urban Heat Island Effect - extreme urban heat
o  At
+1-­‐12oC street
scaleair temperatures
vary
due
toand urban
(Nocturnal temperature difference between urban rural areas – different rates of nighNme cooling) structure and materials
o  Urban density (taller, more compact) typically correlated with higher urban heating
o  Paucity of applications for decision-makers to mitigate and adapt to urban heating
hOp://www.epa.gov/hea*sland/resources/pdf/1_Welcome-­‐Introduc*on_Victoria_Ludwig_US_EPA.pdf Voogt 2015 ASI Scales of Urban Climate
o  urban canopy layer (UCL) = atmospheric zone below mean roof level o  microscale (<102m) exchange processes generate unique “microclimates” o  influenced by its surface properties and structure of its surroundings
2050: 66% 6.3 billion 2014: 54% 3.9 billion AWer Oke 1997, from Voogt 2015 ASI Physical Basis for Urban Effects
o  Cities modify “surface properties” - structure, cover, fabric, metabolism
o  Surface properties govern fundamental energy exchanges o  Occur at multiple spatial and temporal scales
Source: Voogt J, How Researchers Measure Urban Heat Islands -­‐ US EPA The Physics – Surface Energy Balance
2050: 66% 6.3 billion 2014: 54% 3.9 billion AWer Oke 1987, from Voogt 2015 ASI From Grimmond and Christen 2012 Q* = net all-wave radiation flux
QF = anthropogenic heat flux
QH = sensible heat flux QE = latent heat flux
QG = storage heat flux
Surface Temperature - Significance and Uncertainty
2050: 66% 6.3 billion 2014: 54% 3.9 billion from Voogt 2015 ASI
Gaps in urban heat information
o  Active VERTICAL surfaces are unobserved by conventional nadir-sensing
(e.g. satellite) remote technologies
(Voogt and Oke 2003) o  result in directional bias or
“thermal anisotropy” at local scales
o  Up to 12oC difference between
complete and nadir temperatures
o  Not truly “representa*ve” of an urban surface’s thermal state o  Microscale variability of surface temperature due to microstructures – awnings, balconies, etc. -­‐ amplify bias
Voogt and Oke 1997 Significance of Ver*cal Surfaces o  Proportion of walls relative to total 3-D surface area in contact with the
atmosphere: walls in urban core account for 46.7% of total surface area
o  Aerial fraction of the complete urban surface: active surface area is 3 x the plan
area for urban cores
(Source: Ellefsen 1990/91) Data Collection - Instrumentation
Variables
Meteorological
parameters
Thermal
Spectral
albedo
Platform
Sensors and Instruments
3 x net radiometers (Hukseflux NR01)
40mm grey-globe thermometer (Pt100/RAL7001)
3-axis ultrasonic anemometer (Gill WindMaster)
Shielded temp and RH sensor (Rotronic HC-S3)
Barometric pressure sensor (Vaisala PTB 110)
Pyrano-albedometer (Middleton Solar SK16)
2050: 66% 6.3 billion •  FLIR B335, f = 10mm, 45o (IFOV: 2.59 mrad/pixel) •  IR resolution 320 x 240 pixels (DC 2048 x 1536)
•  billion FPA uncooled microbolometer: 7.5 – 13μm
2014: 54% 3.9 •  IR accuracy: ±2°C or 2% of reading
•  IR sensitivity: 0.05°C @ +30°C • 
• 
• 
• 
• 
• 
•  Tetracam ADC multispectral camera
•  3.2 megapixel CMOS sensor 2048 x 1536 pixels
•  3 wavebands 0.52-0.90μm (Red: 0.52 - 0.60μm:
Green: 0.63 - 0.69μm; NIR 0.76 - 0.90μm)
•  f = 8mm (IFOV: 0.54 mrad/pixel) Sydney Case Study Areas – Canyon Structure
•  Sydney Latitude 33°51’ S Longitude 151°12’ E 4.76 million people in June 2013 •  Spatially “representative” urban and suburban canyons in metropolitan Sydney Aspect Ratio H/W
Sky View Factor
Ultimo
H:17.5 W:21 ABS Nearmap 17 November 2015 C1 H/W:0.8
Zetland
H:24.5 W:18 C2 H/W:1.3
LCZ 2 Compact Midrise
Axis Orientation
LCZ 4 Open highrsie
LCZ
Data Processing and Analysis – Thermal Model
visible
multisp
Georeferenced base plan . shp file
ectral 2050: 66% 6.3 billion thermal
2014: 54% 3.9 billion Workflow
Methods
•  Orthomosaic
Photogrammetry
•  Georeferencing
ArcGIS (ArcMap)
•  Cell-based
analysis
•  Raster Analysis
Spatial Analyst Tool
Spatial Modeling and
linear regression
Data Processing and Analysis – Comfort Model
2050: 66% 6.3 billion 2014: 54% 3.9 billion Air temp
Ground surface
temperature 29.32oC av
Wall surface
temperature 28oC av
Ground albedo
0.136 av
19 Nov 2015
9:45-10:05am
KENSINGTON, NSW,-­‐33:54:16, -­‐151:12:50 10am -­‐ AZI:63o 10am -­‐ ALT:63o Data Processing and Analysis – Comfort Model
23 Archibald Ave, Zetland
76 Carlton St, Kensington
1 Regent St, Chippendale
Building
Sensor
Orientation and H/W
ToC and GGT: 5m Max, Min, Ave
ENE
0.85
T
Wall surface
temperature 28oC av
Ground albedo
0.136 av
NNE
0.6
27.8 24.1 26.2
GGT 30.9 26.1 29.9
2014: 54% 3.9 billion Ground surface
temperature 29.32oC av
2050: 66% 6.3 billion 19 Nov 2015
9:45-10:05am
KENSINGTON, NSW,-­‐33:54:16, -­‐151:12:50 10am -­‐ AZI:63o 10am -­‐ ALT:63o 10:35am – 12:30pm; 1.01.2016
T
26.8 24.3 25.6
GGT 27.4 24.4 26.0
2pm – 3:35pm; 1.01.2016
NNE
0.53
T
29.7 28.9 29.2
GGT 31.6 30.0 30.6
1:40pm – 3:05pm; 11.01.2016
The Effect of Facades on Outdoor
Microclimate
Thank you!
[email protected]