Till sidans topp

Sidansvarig: Webbredaktion
Sidan uppdaterades: 2012-09-11 15:12

Tipsa en vän
Utskriftsversion

Different methods for est… - Göteborgs universitet Till startsida
Webbkarta
Till innehåll Läs mer om hur kakor används på gu.se

Different methods for estimating the mean radiant temperature in an outdoor setting

Artikel i vetenskaplig tidskrift
Författare Sofia Thorsson
Fredrik Lindberg
Ingegärd Eliasson
Björn Holmer
Publicerad i International Journal of Climatology
Volym 27
Nummer/häfte 14
Sidor 1983-1993
ISSN 0899-8418
Publiceringsår 2007
Publicerad vid Institutionen för geovetenskaper
Sidor 1983-1993
Språk en
Länkar DOI: 10.1002/joc.1537
Ämnesord mean radiant temperature • outdoor setting • integral radiation measurements • 38 mm flat grey globe thermometer • Rayman 1.2
Ämneskategorier Geovetenskap och miljövetenskap

Sammanfattning

The mean radiant temperature (Tmrt) is one of the most important meteorological parameters governing human energy balance. In this paper, three different methods of obtaining the Tmrt in an outdoor urban setting are compared. Method A is based on integral radiation measurements and angular factors, method B is based on measurements with a 38-mm flat grey globe thermometer and in method C makes use of the Rayman 1.2 software is used. Measurements were performed in a large open square in a high latitude city - Göteborg, Sweden - during clear to overcast weather conditions in October 2005 and in July and August 2006. Results show that the difference between Method A and Method B was generally relatively small. Most of the discrepancy, caused by rapid changes in radiation, temperature and wind speed was smoothed out using 5 min mean values. By systematically and empirically changing the mean convection coefficient, the accuracy of Method B was improved and a new equation expressing the Tmrt was obtained. With this new equation the 38 mm flat grey globe thermometer could successfully be used to estimate the Tmrt in an outdoor urban setting provided that the wind speed and the air and globe temperatures are measured accurately. The study also shows that the flat grey colour of the globe thermometer slightly underestimates the level of short-wave radiation (i.e. sunshine). Method C works very well during the middle of the day in July, i.e. at high sun elevations. However, the model considerably underestimates the Tmrt in the morning and evening in July and during the whole day in October, i.e. at low sun elevations. In outdoor urban settings where thermal comfort researchers or urban planners and designers require an easy and reliable method of estimating mean radiant temperature, the 38 mm flat grey globe thermometer provides a good and cheap solution.

Sidansvarig: Webbredaktion|Sidan uppdaterades: 2012-09-11
Dela:

På Göteborgs universitet använder vi kakor (cookies) för att webbplatsen ska fungera på ett bra sätt för dig. Genom att surfa vidare godkänner du att vi använder kakor.  Vad är kakor?