Globe temperature
The globe thermometer was introduced by Vernon in 1930 as a means of assessing the combined effects of radiation, air temperature and air velocity on human comfort.
It consists of a hollow copper sphere painted matt black to absorb radiant heat, with a temperature sensor at its centre. When it reaches a steady state (after 15 minutes or so depending on the size of the globe and the environmental conditions) the heat exchanges by convection and radiation will be in equilibrium, and the temperature recorded by the sensor will be somewhere between the air and radiant temperature. This is referred to as the globe temperature (tg) or black globe temperature and resembles the thermal conditions felt by the human body.
The standard sphere has a diameter of 150 mm. Other sizes do exist, but the smaller the diameter of the globe, the greater the effect of convection on the temperature recorded.
From the temperature recorded, the mean radiant temperature (mrt) in can be calculated:
MRT = tg + 2.42 x air velocity in m/s (globe temperature – air temperature)
(equation ref Novalynx Corporation 2010 - this equation is dependent on the size and emissivity of the globe thermometer, and the units they show for air velocity are incorrect - cm/s, rather than the correct m/s shown above)
Mean radiant temperature is a measure of the average temperature of the surfaces surrounding a body.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
The 5 elements of seiri, seiton, seiso, seiketsu and shitsuke.
Shading for housing, a design guide
A look back at embedding a new culture of shading.
The Architectural Technology Awards
The AT Awards 2025 are open for entries!
ECA Blueprint for Electrification
The 'mosaic of interconnected challenges' and how to deliver the UK’s Transition to Clean Power.
Grenfell Tower Principal Contractor Award notice
Tower repair and maintenance contractor announced as demolition contractor.
Passivhaus social homes benefit from heat pump service
Sixteen new homes designed and built to achieve Passivhaus constructed in Dumfries & Galloway.
CABE Publishes Results of 2025 Building Control Survey
Concern over lack of understanding of how roles have changed since the introduction of the BSA 2022.
British Architectural Sculpture 1851-1951
A rich heritage of decorative and figurative sculpture. Book review.
A programme to tackle the lack of diversity.
Independent Building Control review panel
Five members of the newly established, Grenfell Tower Inquiry recommended, panel appointed.
Welsh Recharging Electrical Skills Charter progresses
ECA progressing on the ‘asks’ of the Recharging Electrical Skills Charter at the Senedd in Wales.
A brief history from 1890s to 2020s.
CIOB and CORBON combine forces
To elevate professional standards in Nigeria’s construction industry.
Amendment to the GB Energy Bill welcomed by ECA
Move prevents nationally-owned energy company from investing in solar panels produced by modern slavery.
Gregor Harvie argues that AI is state-sanctioned theft of IP.
Experimental AI housing target help for councils
Experimental AI could help councils meet housing targets by digitising records.
BSRIA Occupant Wellbeing survey BOW
Occupant satisfaction and wellbeing tool inc. physical environment, indoor facilities, functionality and accessibility.