- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 14 Jan 2016
Wet-bulb temperature (Twb, Tw or WBT) is the temperature recorded by a thermometer that has its bulb wrapped in cloth and moistened with distilled water. It can be expressed in Celsius (C), Fahrenheit (F) or Kelvin (K).
The rate of evaporation from the wet bulb, and so the temperature it records varies depending on the humidity of the air it is exposed to. The higher the humidity, the lower the rate of evaporation and so the higher the temperature recorded. Wet-bulb temperatures are the same as dry-bulb temperatures at a relative humidity of 100%, but otherwise they will be lower than dry-bulb temperatures due to the cooling effect of evaporation (described as wet-bulb depression).
Wet-bulb temperature is an indicator of the temperature felt when damp skin is exposed to the air and so can be used to express a component of thermal comfort. 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).
 FIND OUT MORE
 Related articles on Designing Buildings Wiki
Featured articles and news
Getting organised below the surface.
Securing suitable water systems.
Love them or hate them, they are popping up everywhere.
The initiative to enhance the environment continues.
Could underused community spaces offer an alternative to working from home?
Keeping workers and workplaces safe in the United States.
A history lesson in geographic information systems.
A low tech, easy to use method of extinguishing small fires.
How can these valued spaces be reused?
Partnership avoids the need for listed building consent.
Connecting building design from inception to completion to operations.
Gregor Harvie predicts interoperability will be construction’s Uber moment.