Dry-bulb temperature
Dry-bulb temperature (Tdb, DBT or Td), is a measure of air temperature. It is referred to as dry-bulb temperature because the thermometer bulb is dry and so the temperature recorded does not vary with the moisture content of the air. This is as opposed to wet-bulb temperature which is the temperature recorded by a thermometer that has its bulb wrapped in cloth and moistened with distilled water. Wet-bulb temperatures are the same as dry-bulb temperatures at a relative humidity of 100%, but otherwise wet-bulb temperatures will be lower than dry-bulb temperatures due to the cooling effect of evaporation (described as wet-bulb depression).
A sling psychrometer holds both wet and dry-bulb thermometers and can be used to express the physical and thermal properties of moist air on a psychrometric chart.
Dry-bulb temperature can be measured by a thermometer exposed to the air but shielded from radiation and moisture. It can be expressed in Celsius (C), Fahrenheit (F) or Kelvin (K).
Dry-bulb temperature can be used as to express a component of thermal comfort. For example, the wet bulb globe temperature index (WBGT) is widely used for the assessment of heat stress and combines wet-bulb temperature, dry-bulb temperature and globe temperature (mean radiant temperature).
[edit] Related articles on Designing Buildings
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.