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

This is an AMP page - Open full page! for all features.

Human Need of Air

Fresh air is required for respiration and for transport of heat and vapor emitted from the human body

Sponsored Links

Respiration

An adult at rest breathes 15 - 18 respiration per minute - exchanging 0.5 liter - approximately 0.5 m3/h. With harder work the rate is 3 to 6 times more (1.5 - 3 m3/h).

The average composition of exhaled air is

  • Oxygen 16.5%
  • Carbon dioxide 4.0%
  • Nitrogen and Argon 79.5%

The quantity of carbon dioxide exhaled in 24 hrs is about 1 kg.

Equilibrium of Heat

Heat is generated within the human body by the combustion of food. The heat is lost from the body by

  • Conduction and convection - about 25%
  • Radiation - about 43%
  • Evaporation and moisture - about 30%
  • Exhaled air - about 2%

Evaporation prevails at high ambient temperatures. Conduction and convection prevails at low ambient temperatures. Heat is liberated in a rate maintaining the internal body temperature at 37oC.

Heat loss from human body

The total heat loss from an adult at normal activity is approximately 118 W (2 Met) in at room with temperatures between 19oC and 34oC.

Dry bulb temperature
(oC)
Load Calculator!
10141822263034
Sensible heat (W)
Load Calculator!
135 112 100 95 84 59 29
Latent heat (W)
Load Calculator!
22 22 22 24 34 59 90
Total heat (W)
Load Calculator!
157 134 122 118 118 118 119
Sponsored Links

Related Topics

Related Documents

Sponsored Links

Share

Search Engineering ToolBox

  • the most efficient way to navigate the 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 the amazing, fun and free SketchUp Make and SketchUp Pro .Add the Engineering ToolBox extension to your SketchUp from the Sketchup Extension Warehouse!

Topics

Unit Converters

Temperature

oC
oF


Load Calculator!

Length

m
km
in
ft
yards
miles
naut miles


Load Calculator!

Area

m2
km2
in2
ft2
miles2
acres


Load Calculator!

Volume

m3
liters
in3
ft3
us gal


Load Calculator!

Weight

kgf
N
lbf


Load Calculator!

Velocity

m/s
km/h
ft/min
ft/s
mph
knots


Load Calculator!

Pressure

Pa (N/m2)
bar
mm H2O
kg/cm2
psi
inches H2O


Load Calculator!

Flow

m3/s
m3/h
US gpm
cfm


Load Calculator!

8 17