Environmental Fluid Mechanics

, Volume 16, Issue 2, pp 347–371 | Cite as

The role of materials selection in the urban heat island effect in dry mid-latitude climates

  • Androula Kakoniti
  • Gregoria Georgiou
  • Konstantinos Marakkos
  • Prashant Kumar
  • Marina K.-A. NeophytouEmail author
Original Article


This work investigates the role of materials selected for different urban surfaces (e.g. on building walls, roofs and pavements) in the intensity of the urban heat island (UHI) phenomenon. Three archetypal street-canyon geometries are considered, reflecting two-dimensional canyon arrays with frontal packing densities (λf) of 0.5, 0.25 and 0.125 under direct solar radiation and ground heating. The impact of radiative heat transfer in the urban environment is examined for each of the different built packing densities. A number of extreme heat scenarios were modelled in order to mimic conditions often found at low- to mid-latitudes dry climates. The investigation involved a suite of different computational fluid dynamics (CFD) simulations using the Reynolds-Averaged Navier–Stokes equations for mass and momentum coupled with the energy equation as well as using the standard k-ε turbulence model. Results indicate that a higher rate of ventilation within the street canyon is observed in areas with sparser built packing density. However, such higher ventilation rates were not necessarily found to be linked with lower temperatures within the canyon; this is because such sparser geometries are associated with higher heat transfer from the wider surfaces of road material under the condition of direct solar radiation and ground heating. Sparser canyon arrays corresponding to wider asphalt street roads in particular, have been found to yield substantially higher air temperatures. Additional simulations indicated that replacing asphalt road surfaces in streets with concrete roads (of different albedo or emissivity characteristics) can lead up to a ~5 °C reduction in the canyon air temperature in dry climates. It is finally concluded that an optimized selection of materials in the urban infrastructure design can lead to a more effective mitigation of the UHI phenomenon than the optimisation of the built packing density.


Heat transfer Urban microclimate Urban design Building design Road design CFD RANS simulations 



Windward (frontal) area of the building array


Building lot area


Specific heat capacity (J kg−1 K−1)


Displacement height (m)


Street canyon height (m)


Turbulent kinetic energy per unit mass (m2 s−2)


Thermal conductivity (W m−1 K−1)


Turbulent thermal conductivity (W m−1 K−1)


Prandtl number (-)


Reynolds number (-)


Richardson number (-)


Ambient air temperature (K)


Ambient (inlet) reference air temperature (K)

TS, Thot

Street surface temperature (K)


Air temperature for thermal comfort (=298 K)


Computed temperature (K)


Friction velocity (m s−1)


Ambient air velocity magnitude (m s−1)


Mean streamwise and vertical velocity (m s−1)


Dimensionless velocity magnitude (=U/Uambient)


Street canyon width (m)


Surface roughness length (m)


Boundary layer height (m)


Emissivity (-)


Dissipation rate of turbulent kinetic energy (m2 s−3)


Von Karman constant (0.4)


Frontal packing density (−)


Density (kg m−3)



The authors wish to acknowledge the anonymous reviewers for comments and suggestions that helped to improve substantially the manuscript. Part of this work was funded by the Cyprus Research Promotion Foundation under the contracts ΑΕΙΦΟΡΙΑ/ΑΣΤΙ/0308(ΒΙΕ) as well as ΑΝΑΒΑΘΜΙΣΗ/ΠΑΓΙΟ/0308/33. Drs. Prashant Kumar and Marina Neophytou also acknowledge the funding support received from the Erasmus Exchange programme that allowed them to interact and develop this article collaboratively. MKAN also acknowledges Mr Nestoras Antoniou for assistance in the post-processing and figure production during the revision process.


  1. 1.
    Allegrini J, Dorer V, Carmeliet J (2013) Wind tunnel measurements of buoyant flows in street canyons. Build Environ 59:315–326CrossRefGoogle Scholar
  2. 2.
    Allegrini J, Dorer V, Carmeliet J (2014) Buoyant flows in street canyons: validation of CFD simulations with wind tunnel measurements. Build Environ 72:63–74CrossRefGoogle Scholar
  3. 3.
    Bansal NK, Garg SN, Kothari S (1992) Effect of exterior surface colour on the thermal performance of buildings. Build Environ 27:31–37CrossRefGoogle Scholar
  4. 4.
    Bezpalcova K, Harms F (2005) EWTL data report/part I: summarized test description mock urban setting test. Environmental Wind Tunnel Laboratory, Centre for Marine and Atmospheric Research, University of Hamburg, HamburgGoogle Scholar
  5. 5.
    Bretz S, Akbari H, Rosenfeld A (1998) Practical issues for using solar-reflective materials to mitigate urban heat islands. Atmos Environ 32:95–101CrossRefGoogle Scholar
  6. 6.
    Britter RE, Hanna SR (2003) Flow and dispersion in urban areas. Annu Rev Fluid Mech 35:469–496CrossRefGoogle Scholar
  7. 7.
    Brown MJ, Lawson RE, DeCroix DS, Lee RL (2001) Comparison of centerline velocity measurements obtained around 2D and 3D buildings arrays in a wind tunnel. Report LA-UR-01-4138, Los Alamos National Laboratory, Los AlamosGoogle Scholar
  8. 8.
    Castro IP (2003) CFD for external aerodynamics in the built environment. QNETCFD Netw Newsl 2:4–7Google Scholar
  9. 9.
    CRES (1999) A guide for energy saving through heat isolation, Report E.P.E./3.4.6, Cres, (In Greek)Google Scholar
  10. 10.
    Dallman A, Magnusson S, Britter RE, Norford L, Entekhabi D, Fernando HJS (2014) Conditions for thermal circulation in urban street canyons. Build Environ 80:184–191CrossRefGoogle Scholar
  11. 11.
    Defraeye T, Blocken B, Carmeliet J (2011) Convective heat transfer coefficients for exterior building surfaces: existing correlations and CFD modelling. Energy Convers Manag 52:512–522CrossRefGoogle Scholar
  12. 12.
    Doulos L, Santamouris M, Livada I (2004) Passive cooling of outdoor urban spaces. The role of materials. Solar Energy 77:231–249CrossRefGoogle Scholar
  13. 13.
    Fernando HJS (2010) Fluid dynamics of urban atmospheres in complex terrain. Ann Rev Fluid Mech 42:365–389CrossRefGoogle Scholar
  14. 14.
    Fluent Inc (2005) FLUENT 6.2 User’s guide. Fluent Inc, LebanonGoogle Scholar
  15. 15.
    Franke J, Hellsen A, Schlunzen H, Carissimo B (2007) Best practice guideline for the CFD simulation of flows in the urban environment, EU-COST Action 732, May 2007Google Scholar
  16. 16.
    Gromke C, Blocken B (2015) Influence of avenue-trees on air quality at the urban neighborhood scale. Part II: traffic pollutant concentrations at pedestrian level. Environ Pollut 196:176–184CrossRefGoogle Scholar
  17. 17.
    Hamlyn D, Britter RE (2005) A numerical study of the flow field and exchange processes within a canopy of urban-type roughness. Atmos Environ 39:3243–3254CrossRefGoogle Scholar
  18. 18.
    IPCC (2007) In: S Soloman, D Qin, M Manning, Z Chen, M Marquis, KB Averyt, M Tignor, HL Miller (eds) Climate change 2007: the physical science basis. Contribution of working group I to the fourth assessment report of the intergovernmental panel on climate change. Cambridge University Press, CambridgeGoogle Scholar
  19. 19.
    Kumar P, Garmory A, Ketzel M, Berkowicz R, Britter R (2009) Comparative study of measured and modelled number concentrations of nanoparticles in an urban street canyon. Atmos Environ 43:949–958CrossRefGoogle Scholar
  20. 20.
    Kumar P, Morawska L (2013) Energy-pollution nexus for urban buildings. Environ Sci Technol 47:7591–7592CrossRefGoogle Scholar
  21. 21.
    Kumar P, Morawska L, Birmili W, Paasonen P, Hu M, Kulmala M, Harrison RM, Norford L, Britter R (2014) Ultrafine particles in cities. Environ Int 66:1–10CrossRefGoogle Scholar
  22. 22.
    Kumar P, Morawska L, Martani C, Biskos G, Neophytou M, Di Sabatino S, Bell M, Norford L, Britter R (2015) The rise of low cost sensing for managing air pollution in cities. Environ Int 75:199–205CrossRefGoogle Scholar
  23. 23.
    Launder BE, Spalding DB (1974) The numerical computation of turbulent flows. Comput Methods Appl Mech Eng 3:269–289CrossRefGoogle Scholar
  24. 24.
    Louka P, Vachon G, Sini JF, Mestayer PG, Rosant JM (2002) Thermal effects on the airflow in a street canyon-Nantes’99 experimental results and model simulation. Water Air Soil Pollut 2:351–364CrossRefGoogle Scholar
  25. 25.
    Macdonald RW, Schofield SC, Slawson PR (2002) Physical modelling of urban roughness using arrays of regular roughness elements. Water Air Soil Pollut 2:541–554CrossRefGoogle Scholar
  26. 26.
    Magnusson S, Dallman A, Entekhabi D, Britter R, Fernando HJS, Norford L (2014) On thermally forced flows in urban street canyons. Environ Fluid Mech 14:1427–1441CrossRefGoogle Scholar
  27. 27.
    Memon RA, Leung DYC, Liu C-H (2010) Effects of building aspect ratio and wind speed on air temperatures in urban-like street canyons. Build Environ 45:176–188CrossRefGoogle Scholar
  28. 28.
    Mouzourides P, Kumar P, Neophytou MKA (2015) Assessment of long-term measurements of particulate matter and gaseous pollutants in South-East Mediterranean. Atmos Environ. doi: 10.1016/j.atmosenv.2015.02.031 Google Scholar
  29. 29.
    Mouzourides P, Kyprianou A, Brown MJ, Carissimo B, Choudhary R, Neophytou MKA (2014) Searching for the distinctive signature of a city: could the MRA provide the DNA of a city? Urban Climate (in press). doi: 10.1016/j.uclim.2014.04.001 Google Scholar
  30. 30.
    Mouzourides P, Kyprianou A, Neophytou MKA (2013) A scale-adaptive approach for spatially-varying urban morphology characterization in the boundary layer parameterization using multi-resolution analysis. Bound-Layer Meteorol 149(3):455–481. doi: 10.1007/s10546-013-9848-4 CrossRefGoogle Scholar
  31. 31.
    Neophytou MK, Goussis DA, Mastorakos E, Britter RE (2005) The conceptual development of a simple scale-adaptive reactive pollutant dispersion model. Atmos Environ 39:2787–2794CrossRefGoogle Scholar
  32. 32.
    Neophytou MKA, Markides CN, Fokaides PA (2014) The flow through homogeneous urban street-canyon geometries and deductions for urban-scale parameterizations for atmospheric boundary layer modeling: an experimental study using particle image velocimetry. Phys Fluids 26:086603. doi: 10.1063/1.4892979 CrossRefGoogle Scholar
  33. 33.
    Panagiotou I, Neophytou MKA, Hamlyn D, Britter RE (2013) City breathability as quantified by the exchange velocity and its spatial variation in real inhomogeneous urban geometries: an example from central London area. Sci Total Environ 442:466–477CrossRefGoogle Scholar
  34. 34.
    Park SB, Baik JJ, Raasch S, Letzel MO (2012) A large-eddy simulation study of thermal effects on turbulent flow and dispersion in and above a street canyon. J Appl Meteorol Climatol 51(5):829–841CrossRefGoogle Scholar
  35. 35.
    Santamouris M (2001) Energy and climate in the urban building environment. James and James Science Publishers, LondonGoogle Scholar
  36. 36.
    Santiago J, Martilli A, Martín F (2007) CFD simulation of airflow over a regular array of cubes. Part I: Three-dimensional simulation of the flow and validation with wind-tunnel measurements. Bound-Layer Meteorol 122:609–634CrossRefGoogle Scholar
  37. 37.
    Santiago JL, Dejoan A, Martilli A, Martin F, Pinelli A (2009) LES and RANS simulations of the MUST expriment. Study of indent wind direction effects on the flow and plume dispersion. In: The 7th International Conference on Urban Climate 2009, YokohamaGoogle Scholar
  38. 38.
    Schatzmann M, Britter RE (2010) COST Action 732 model evaluation case studies: approach and results: quality assurance and improvement of microscale meteorological models. COST OfficeGoogle Scholar
  39. 39.
    Schwarz-van Manen AD, Geloven AFM, Nieuwenhuizen J, Stouthart JC, Krishna Prasad K, Nieuwstadt FTM (1993) Friction velocity and virtual origin estimates for mean velocity profiles above smooth and triangular riblet surfaces. Appl Sci Res 50:233–254CrossRefGoogle Scholar
  40. 40.
    Simpson JR, McPherson EG (1998) Simulation of tree shade impacts on residential energy use for space conditioning in Sacramento. Atmos Environ 32:69–74CrossRefGoogle Scholar
  41. 41.
    Solazzo E, Britter RE (2007) Transfer processes in a simulated urban street canyon. Bound Layer Meteorol 124:43–60CrossRefGoogle Scholar
  42. 42.
    Synnefa A, Santamouris M, Livada I (2006) A study of the thermal performance of reflective coatings for the urban environment. Sol Energy 80:968–981CrossRefGoogle Scholar
  43. 43.
    Tan S-A, Fwa T-F (1992) Influence of pavement materials on the thermal environment of outdoor spaces. Build Environ 27:289–295CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2015

Authors and Affiliations

  • Androula Kakoniti
    • 1
  • Gregoria Georgiou
    • 1
  • Konstantinos Marakkos
    • 1
    • 4
  • Prashant Kumar
    • 2
    • 3
  • Marina K.-A. Neophytou
    • 1
    Email author
  1. 1.Environmental Fluid Mechanics Laboratory, Department of Civil and Environmental EngineeringUniversity of CyprusNicosiaCyprus
  2. 2.Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences (FEPS)University of SurreyGuildfordUK
  3. 3.Environmental Flow (EnFlo) Research Centre, FEPSUniversity of SurreyGuildfordUK
  4. 4.The Cyprus Institute, Energy and Environment and Water Research CenterNicosiaCyprus

Personalised recommendations