Assessing the accuracy of globe thermometer method in predicting outdoor mean radiant temperature under Malaysia tropical microclimate

N. G. Khrit, M. A. Alghoul, Kamaruzzaman Sopian, A. A. Lahimer, O. K. Elayeb

Research output: Contribution to journalArticle

Abstract

Assessing outdoor human thermal comfort and urban climate quality require experimental investigation of microclimatic conditions and their variations in open urban spaces. For this, it is essential to provide quantitative information on air temperature, humidity, wind velocity and mean radiant temperature. These parameters can be quantified directly except mean radiant temperature (Tmrt). The most accurate method to quantify Tmrt is integral radiation measurements (3-D shortwave and long-wave) which require using expensive radiometer instruments. To overcome this limitation the well-known globe thermometer method was suggested to calculate Tmrt. The aim of this study was to assess the possibility of using indoor globe thermometer method in predicting outdoor mean radiant temperature under Malaysia tropical microclimate. Globe thermometer method using small and large sizes of black-painted copper globes (50mm, 150mm) were used to estimate Tmrt and compare it with the reference Tmrt estimated by integral radiation method. The results revealed that the globe thermometer method considerably overestimated Tmrt during the middle of the day and slightly underestimated it in the morning and late evening. The difference between the two methods was obvious when the amount of incoming solar radiation was high. The results also showed that the effect of globe size on the estimated Tmrt is mostly small. Though, the estimated Tmrt by the small globe showed a relatively large amount of scattering caused by rapid changes in radiation and wind speed.

Original languageEnglish
Article number01006
JournalE3S Web of Conferences
Volume23
DOIs
Publication statusPublished - 20 Nov 2017

Fingerprint

Thermometers
microclimate
temperature
Temperature
Radiation
wind velocity
method
urban climate
Thermal comfort
Radiometers
radiometer
Solar radiation
solar radiation
humidity
air temperature
Atmospheric humidity
scattering
copper
Scattering
Copper

ASJC Scopus subject areas

  • Environmental Science(all)
  • Energy(all)
  • Earth and Planetary Sciences(all)

Cite this

Assessing the accuracy of globe thermometer method in predicting outdoor mean radiant temperature under Malaysia tropical microclimate. / Khrit, N. G.; Alghoul, M. A.; Sopian, Kamaruzzaman; Lahimer, A. A.; Elayeb, O. K.

In: E3S Web of Conferences, Vol. 23, 01006, 20.11.2017.

Research output: Contribution to journalArticle

@article{0a6fc65ce9724ff6a231f07e9134cae5,
title = "Assessing the accuracy of globe thermometer method in predicting outdoor mean radiant temperature under Malaysia tropical microclimate",
abstract = "Assessing outdoor human thermal comfort and urban climate quality require experimental investigation of microclimatic conditions and their variations in open urban spaces. For this, it is essential to provide quantitative information on air temperature, humidity, wind velocity and mean radiant temperature. These parameters can be quantified directly except mean radiant temperature (Tmrt). The most accurate method to quantify Tmrt is integral radiation measurements (3-D shortwave and long-wave) which require using expensive radiometer instruments. To overcome this limitation the well-known globe thermometer method was suggested to calculate Tmrt. The aim of this study was to assess the possibility of using indoor globe thermometer method in predicting outdoor mean radiant temperature under Malaysia tropical microclimate. Globe thermometer method using small and large sizes of black-painted copper globes (50mm, 150mm) were used to estimate Tmrt and compare it with the reference Tmrt estimated by integral radiation method. The results revealed that the globe thermometer method considerably overestimated Tmrt during the middle of the day and slightly underestimated it in the morning and late evening. The difference between the two methods was obvious when the amount of incoming solar radiation was high. The results also showed that the effect of globe size on the estimated Tmrt is mostly small. Though, the estimated Tmrt by the small globe showed a relatively large amount of scattering caused by rapid changes in radiation and wind speed.",
author = "Khrit, {N. G.} and Alghoul, {M. A.} and Kamaruzzaman Sopian and Lahimer, {A. A.} and Elayeb, {O. K.}",
year = "2017",
month = "11",
day = "20",
doi = "10.1051/e3sconf/20172301006",
language = "English",
volume = "23",
journal = "E3S Web of Conferences",
issn = "2267-1242",
publisher = "EDP Sciences",

}

TY - JOUR

T1 - Assessing the accuracy of globe thermometer method in predicting outdoor mean radiant temperature under Malaysia tropical microclimate

AU - Khrit, N. G.

AU - Alghoul, M. A.

AU - Sopian, Kamaruzzaman

AU - Lahimer, A. A.

AU - Elayeb, O. K.

PY - 2017/11/20

Y1 - 2017/11/20

N2 - Assessing outdoor human thermal comfort and urban climate quality require experimental investigation of microclimatic conditions and their variations in open urban spaces. For this, it is essential to provide quantitative information on air temperature, humidity, wind velocity and mean radiant temperature. These parameters can be quantified directly except mean radiant temperature (Tmrt). The most accurate method to quantify Tmrt is integral radiation measurements (3-D shortwave and long-wave) which require using expensive radiometer instruments. To overcome this limitation the well-known globe thermometer method was suggested to calculate Tmrt. The aim of this study was to assess the possibility of using indoor globe thermometer method in predicting outdoor mean radiant temperature under Malaysia tropical microclimate. Globe thermometer method using small and large sizes of black-painted copper globes (50mm, 150mm) were used to estimate Tmrt and compare it with the reference Tmrt estimated by integral radiation method. The results revealed that the globe thermometer method considerably overestimated Tmrt during the middle of the day and slightly underestimated it in the morning and late evening. The difference between the two methods was obvious when the amount of incoming solar radiation was high. The results also showed that the effect of globe size on the estimated Tmrt is mostly small. Though, the estimated Tmrt by the small globe showed a relatively large amount of scattering caused by rapid changes in radiation and wind speed.

AB - Assessing outdoor human thermal comfort and urban climate quality require experimental investigation of microclimatic conditions and their variations in open urban spaces. For this, it is essential to provide quantitative information on air temperature, humidity, wind velocity and mean radiant temperature. These parameters can be quantified directly except mean radiant temperature (Tmrt). The most accurate method to quantify Tmrt is integral radiation measurements (3-D shortwave and long-wave) which require using expensive radiometer instruments. To overcome this limitation the well-known globe thermometer method was suggested to calculate Tmrt. The aim of this study was to assess the possibility of using indoor globe thermometer method in predicting outdoor mean radiant temperature under Malaysia tropical microclimate. Globe thermometer method using small and large sizes of black-painted copper globes (50mm, 150mm) were used to estimate Tmrt and compare it with the reference Tmrt estimated by integral radiation method. The results revealed that the globe thermometer method considerably overestimated Tmrt during the middle of the day and slightly underestimated it in the morning and late evening. The difference between the two methods was obvious when the amount of incoming solar radiation was high. The results also showed that the effect of globe size on the estimated Tmrt is mostly small. Though, the estimated Tmrt by the small globe showed a relatively large amount of scattering caused by rapid changes in radiation and wind speed.

UR - http://www.scopus.com/inward/record.url?scp=85036606204&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85036606204&partnerID=8YFLogxK

U2 - 10.1051/e3sconf/20172301006

DO - 10.1051/e3sconf/20172301006

M3 - Article

VL - 23

JO - E3S Web of Conferences

JF - E3S Web of Conferences

SN - 2267-1242

M1 - 01006

ER -