Thermal footprint effect of rooftop urban cooling strategies

Dylan Botham-Myint, Gerald W. Recktenwald, David Sailor

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Simulation results indicate that urban morphology plays an important role in determining the efficacy of rooftop urban cooling strategies for improving pedestrian thermal comfort. Results suggest that a white roof has the greatest effect on near-surface air temperatures within the urban canyon when used on buildings of 1-2 stories height and almost no near-surface effect when applied to 4 story buildings. However, the near-surface effect is more substantial when complex urban morphology introduces enhanced vertical mixing. Of the cases studied the largest near-surface cooling benefit of implementing white roofs was found for the case when a taller building existed downwind from a building with a white roof. Using the Thermal Footprint Ratio it was found that by placing a tall building behind a building with a white roof in an otherwise uniform array of 2 story buildings, the cool roof would be twice as effective at reducing air temperatures at the pedestrian level. Calculations of the volumetric heat removal confirmed this result, indicating that the positioning of the tall building downwind of the modified roof would be 2.6 times as effective at cooling the pedestrian level air volume as compared to the case where all buildings were a uniform height.

Original languageEnglish (US)
JournalUrban Climate
DOIs
StateAccepted/In press - May 5 2015

Fingerprint

footprint
roof
building
cooling
pedestrian
urban morphology
air
air temperature
vertical mixing
positioning
canyon
effect
surface temperature
heat
simulation

Keywords

  • Building heights
  • Cool roofs
  • Heat island mitigation
  • Urban climate
  • Urban heat islands

ASJC Scopus subject areas

  • Atmospheric Science
  • Environmental Science (miscellaneous)
  • Geography, Planning and Development
  • Urban Studies

Cite this

Thermal footprint effect of rooftop urban cooling strategies. / Botham-Myint, Dylan; Recktenwald, Gerald W.; Sailor, David.

In: Urban Climate, 05.05.2015.

Research output: Contribution to journalArticle

Botham-Myint, Dylan ; Recktenwald, Gerald W. ; Sailor, David. / Thermal footprint effect of rooftop urban cooling strategies. In: Urban Climate. 2015.
@article{2000de1313a649fa988e3141dbf01ad1,
title = "Thermal footprint effect of rooftop urban cooling strategies",
abstract = "Simulation results indicate that urban morphology plays an important role in determining the efficacy of rooftop urban cooling strategies for improving pedestrian thermal comfort. Results suggest that a white roof has the greatest effect on near-surface air temperatures within the urban canyon when used on buildings of 1-2 stories height and almost no near-surface effect when applied to 4 story buildings. However, the near-surface effect is more substantial when complex urban morphology introduces enhanced vertical mixing. Of the cases studied the largest near-surface cooling benefit of implementing white roofs was found for the case when a taller building existed downwind from a building with a white roof. Using the Thermal Footprint Ratio it was found that by placing a tall building behind a building with a white roof in an otherwise uniform array of 2 story buildings, the cool roof would be twice as effective at reducing air temperatures at the pedestrian level. Calculations of the volumetric heat removal confirmed this result, indicating that the positioning of the tall building downwind of the modified roof would be 2.6 times as effective at cooling the pedestrian level air volume as compared to the case where all buildings were a uniform height.",
keywords = "Building heights, Cool roofs, Heat island mitigation, Urban climate, Urban heat islands",
author = "Dylan Botham-Myint and Recktenwald, {Gerald W.} and David Sailor",
year = "2015",
month = "5",
day = "5",
doi = "10.1016/j.uclim.2015.07.005",
language = "English (US)",
journal = "Urban Climate",
issn = "2212-0955",
publisher = "Elsevier BV",

}

TY - JOUR

T1 - Thermal footprint effect of rooftop urban cooling strategies

AU - Botham-Myint, Dylan

AU - Recktenwald, Gerald W.

AU - Sailor, David

PY - 2015/5/5

Y1 - 2015/5/5

N2 - Simulation results indicate that urban morphology plays an important role in determining the efficacy of rooftop urban cooling strategies for improving pedestrian thermal comfort. Results suggest that a white roof has the greatest effect on near-surface air temperatures within the urban canyon when used on buildings of 1-2 stories height and almost no near-surface effect when applied to 4 story buildings. However, the near-surface effect is more substantial when complex urban morphology introduces enhanced vertical mixing. Of the cases studied the largest near-surface cooling benefit of implementing white roofs was found for the case when a taller building existed downwind from a building with a white roof. Using the Thermal Footprint Ratio it was found that by placing a tall building behind a building with a white roof in an otherwise uniform array of 2 story buildings, the cool roof would be twice as effective at reducing air temperatures at the pedestrian level. Calculations of the volumetric heat removal confirmed this result, indicating that the positioning of the tall building downwind of the modified roof would be 2.6 times as effective at cooling the pedestrian level air volume as compared to the case where all buildings were a uniform height.

AB - Simulation results indicate that urban morphology plays an important role in determining the efficacy of rooftop urban cooling strategies for improving pedestrian thermal comfort. Results suggest that a white roof has the greatest effect on near-surface air temperatures within the urban canyon when used on buildings of 1-2 stories height and almost no near-surface effect when applied to 4 story buildings. However, the near-surface effect is more substantial when complex urban morphology introduces enhanced vertical mixing. Of the cases studied the largest near-surface cooling benefit of implementing white roofs was found for the case when a taller building existed downwind from a building with a white roof. Using the Thermal Footprint Ratio it was found that by placing a tall building behind a building with a white roof in an otherwise uniform array of 2 story buildings, the cool roof would be twice as effective at reducing air temperatures at the pedestrian level. Calculations of the volumetric heat removal confirmed this result, indicating that the positioning of the tall building downwind of the modified roof would be 2.6 times as effective at cooling the pedestrian level air volume as compared to the case where all buildings were a uniform height.

KW - Building heights

KW - Cool roofs

KW - Heat island mitigation

KW - Urban climate

KW - Urban heat islands

UR - http://www.scopus.com/inward/record.url?scp=84939526910&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84939526910&partnerID=8YFLogxK

U2 - 10.1016/j.uclim.2015.07.005

DO - 10.1016/j.uclim.2015.07.005

M3 - Article

AN - SCOPUS:84939526910

JO - Urban Climate

JF - Urban Climate

SN - 2212-0955

ER -