Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

# Wet Bulb Globe Temperature (WBGT)

## The Wet Bulb Globe Temperature can be used to measure the general Heat-Stress index.

The Wet Bulb Globe Temperature (WBGT) can be measured by

• the black globe temperature
• the natural wet-bulb temperature

The Wet Bulb Globe Temperature (WBGT) for outdoor conditions:

WBGT = 0.7 Tnwb + 0.2 Tg + 0.1 Ta                                (1)

where

WBGT = the Wet Bulb Globe Temperature (oC)

Tnwb =  the natural wet-bulb temperature (oC)

Tg = the black globe temperature (oC)

Ta = the (shade) air temperature (oC)

#### The black globe thermometer (Tg)

A 150 mm (6 inch) black globe with a thermometer located at the centre.

Represents the integrated effects of radiation and wind.

#### The natural wet-bulb temperature (Tnwb)

A thermometer with its bulb covered with a wettened cotton wick supplied with water. Evaporation cools the thermometer. Not shielded from wind or radiation.

Represents the integrated effect of humidity, wind and radiation.

#### The (shade) air temperature (Ta)

Measured by a thermometer shielded from radiation.

### Indoor - with negligible Solar Radiation

The Wet Bulb Globe Temperature (WBGT) can be calculated for indoor conditions as

WBGT = 0.7 Tnwb + 0.3 Tg                            (2)

## Related Topics

• ### Air Psychrometrics

Moist and humid air - psychrometric charts, Mollier diagrams, air-condition temperatures and absolute and relative humidity and moisture content.
• ### Physiology

Human physiology, air quality and comfort temperatures, activity and metabolic rates, health effects of carbon monoxide and more.

## Related Documents

• ### Air - Humidity Measurement from Dry and Wet Bulb Temperature

Relative humidity in moist air can estimated by measuring the dry and wet bulb temperature.
• ### Compressible Gas Flow - Entropy

Calculating the entropy in a compressible gas flow.
• ### Dry Bulb, Wet Bulb and Dew Point Temperatures

Dry Bulb, Wet Bulb and Dew Point temperatures can be used to determine the state of humid air.
• ### Heat Index

Equivalent heat index vs. air temperature and relative humidity - in degrees Fahrenheit and Celsius.
• ### Indoor Comfort Temperatures vs. Outdoor Temperatures

Recommended indoor comfort temperatures vs. outdoor temperatures.
• ### Indoor Conditions - Summer or Winter

Recommended indoor design conditions summer or winter.
• ### Metabolic Heat Gain from Persons

Human metabolic heat gain in air conditioned rooms.
• ### Moist Air - Psychrometric Terms

Dry and wet bulb temperature, specific volume, relative humidity,  enthalpy and more.
• ### Moist Air - Relative Humidity

Relative humidity in moist air is the ratio of partial vapor pressure to air pressure.
• ### Moist Air - Water Vapor and Saturation Pressure

Saturation pressure of water vapor in moist air vs. temperature.
• ### Predicted Mean Vote Index (PMV)

PMV index predicts mean comfort response of a larger group of people.
• ### Solar Heat Transmission through Windows

Solar heat gain through windows with roller shades, vertical blinds and Venetian blinds
• ### Wet Bulb Globe Temperature (WBGT)

The Wet Bulb Globe Temperature can be used to measure the general Heat-Stress index.
• ### Wet Bulb Globe Temperature (WBGT)

The Wet Bulb Globe Temperature can be used to measure the general Heat-Stress index.

## Search

Search is the most efficient way to navigate the Engineering ToolBox.

## Engineering ToolBox - SketchUp Extension - Online 3D modeling!

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with older versions of the amazing SketchUp Make and the newer "up to date" SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp Make/Pro from the Extension Warehouse !

We don't collect information from our users. More about

## Citation

• The Engineering ToolBox (2010). Wet Bulb Globe Temperature (WBGT). [online] Available at: https://www.engineeringtoolbox.com/wet-bulb-globe-temperature-WBGT-d_1630.html [Accessed Day Month Year].

Modify the access date according your visit.

12.8.9